Hi Leo! If you decide to go the mild steel route, and are looking for a manufacturer, let me know. I run a fabrication shop in Indiana, and if you have DXF files of the design, I could have these made very quickly (5-8 days) and could do for cost just so I can say our company made something for this amazing project. We have cnc lasers and some amazing welders. We do mainly MIG welding , which isn’t the best welding application for aluminum but we do have aluminum laser cutting and aluminum mig welding capabilities…. We have made many tanks for very large international companies which I could share with you in a private message. Obviously we would pressure test them in house before ever shipping them. Let me know! I take as much pride in our work as you do yours. Love the project, have followed from the beginning.
Thank you so much David! And sorry for the delay, I only just saw this comment. I think we are on track with a good plan now but I really appreciate the offer and will be back in touch if if falls though! Thanks again
Hey Leo. THIS IS IMPORTANT. IF YOU READ NOTHING ELSE, PLEASE READ THE PART THAT ARE WRITTEN IN CAPS. I can finally give you advice from my expertise that will help. I was lucky enough to happen along your podcasts at episode #3. So after quickly catching up with #1 and #2 I've been completely fascinated by your wherewithal, knowledge, tenacity, perseverance and your even-keeled personality. I haven't missed an episode since. Not Australian, but I have to say, "Good on ya, Mate!" Now, coming from an aviation background it never seemed possible that I could ever be of assistance with anything you are doing, but now I can. SO PLEASE HEAR THIS... STOP WRAPPING UP YOUR POLY TANKS TO SEND BACK. KEEP THEM. THEY ARE ABSOLUTELY BEAUTIFUL IN BOTH FORM AND FUNCTION. ALL YOU NEED TO DO IS SEND THE SPECS TO AN AVIATION FUEL BLADDER MAKING COMPANY AND YOU CAN USE THOSE TANKS AS-IS AND THE BLADDER WILL SUPPLY ALL THE LEAK-PROOFING YOU WILL EVER NEED - FOREVER! Fuel bladders in the wings of airplanes is as common as wings. As well, should there ever be any leakage (hard to imagine - but accidents can happen), the bladder is relatively easy to remove and replace (always keeping ease of maintenance in mind). Since leakage through the plastic would no longer be a problem, it would be easy to cut an access hatch in the top of each plastic tank in order to facilitate installing, and possibly removing and replacing the bladder should it be needed at some time in the future. I HAVE EVERY CONFIDENCE THAT THIS WOULD WORK REALLY WELL AND WOULD BE, BY FAR, THE MOST EXPEDIENT AND EFFICIENT WAY TO SOLVE THIS PROBLEM. AS WELL, IT MAY ALSO BE THE LEAST COSTLY. YOU COULD EVEN HAVE TWO BLADDERS PER TANK MADE AND THEN BE ABLE TO REPLACE A BLADDER IMMEDIATELY AND ON-THE-GO, SHOULD WORSE COME TO WORSE FOR SOME REASON. I'm grateful for the opportunity to finally be able to provide something from my expertise in order to help you with something in your expertise. I'm really looking forward to the time when I'll be able to follow you through some of your early voyages in this wonderful boat (though you haven't mentioned this prospect yet.) BTW: With enough research and ingenuity, it would be possible that you, or your team, could actually make custom bladders yourselves. Ambitious, but a do-able thing. Getting proficient at heat sealing and gluing isn't an impossible task at all. After all, the bladder doesn't have to hold any pressure at all. It's just a fuel barrier. Practice a little bit on small scale stuff and I'm confident you would do fine. Will Robertson
45 years in the aviation industry pilot/ame fuel bladders are absolutely the way to go period I can attest to personal experience including ballistic self sealing tanks used in the military.
I was thinking on these lines. Integral aliminumen tanks in no bladder tanks we used to add Prist to the fuel (Jet A1) it mixed with any water in the fuel and supposedly made the water an inhibiter, It's a long time since I worked with aircraft so it may not be used these days. I'm sure someone will know. LOL
I am a machinist many years thinking outside the box. So I researched your tank problem and I have a suggestion. As you know a leaking fuel tank has a serious accessibility problem. I see where you are installing your tanks. Consider using 8 X Aluminum Coal Tar Epoxy double coated tanks, 4 x each side. This will reduce the size and allow removal of individual leaking tanks later without ripping your precious Tally Ho to pieces removing a monster size tank. Leaking tanks can be emptied and bypassed at sea until it is more convenient to service. Love you ALL.
That idea makes good sense. Even just breaking the two large tanks down to 4 or 6 smaller tanks. The ease and convenience of repairs or replacement would justify the weight of the additional material. They could be secured to one another to minimize any wear from movement.
@@LesFelts Yes, smaller tanks would be better from a maintenance view for sure. Also when the Boat is moving around in the sea less diesel will move around in the tanks with less internal forces. So this solution seems the way to go I think. Perhaps even a good way to have control of how much diesel is left at a given time will be easier to see.
What a great idea. Smaller tanks prevent sloshing. Large tanks usually would have a slosh baffle, but joining smaller tanks prevents the need for those. I didn't see any outline of slosh baffles in those plastic welded tanks
Big tanks for bulk transport, small tanks for survivability. Rather than plumbing each tank to the next, run a single feed line with T joints and valve to each tank. So any tank can be isolated and removed without effecting the function of the overall fuel storage. The catch, it will increase weight and reduce capacity.
They may have and they may have met the standard for diesel fuel. Nitrogen is a tiny atom and can fit through gaps that no other atom would fit through. So while it may leak with nitrogen, there could be zero chance of diesel or even other gaseous atoms leaking.
21:04 you're hand hammering with the mallet inches away!! Those hands will be upset with you in the years to come! Haha use the tools! Anyways nice to see you enjoy the project and the fun environment 🙂
Always great to see new faces aboard Nic. I hope you enjoy your time and also mutually learn a lot from Leo, his great crew and each other. I am sure you will be a great asset to the team.
Really cool to see two separate craftsman I have watched before come together. It was a bit like an Avengers movie. All you need now is Mr chickadee making some Poplar binnacle or something like that.
As an old(very old) Royal Navy shipwright (or artificer as we became) It makes me so happy to see you young engineers and volunteers keeping the old traditional working skills alive. Well done all of you.
"Artificer" can also describe my abilities with computers. I can still program for DOS in assembly using MS Debug as an assembler instead of using a compiler. Translation: I can make my own tools for any need in the old ship by using a pocket knife and a file. I am always glad to know other "artificers" are still around.
Hi Leo. First, thanks for all your videos. I'm a mariner and sailor and grew up on the Pacific Ocean. I've worked in and on many boats and have owned a few sailboats. My wife and I wife sailed our Morgan 382 more than 25,000 miles south from San Francisco along California and the Pacific coast of Mexico, visiting many of the anchorages between there and those along Central American countries until we reached the Panama Canal. Then it was off to the Galapagos Islands for a couple months. We cruised through all the South Pacific islands we could find, finally arriving in New Zealand/Australian waters with tropical cyclones threatening north of us. We eventually swallowed the hook after a couple great years down under. We had the same Westerbeke engine as you -- you made a good choice. Regarding the fuel tank questions you have, if you do it correctly, virtually all the materials you mentioned will work. I have personal experience with Aluminum, Fiberglass, and Mild Steel. The big thing with aluminum is corrosion, not just from salt water, but also from any galvanic dissimilar metals that come into contact with aluminum. A bit of spilled mercury or copper bits resting on aluminum in salt air will hole it. Fiberglass is fine. I've had both solid fiberglass and fiberglass over marine plywood tanks. Made carefully, they don't leak, but I sense that the ply + glass is weaker than solid fg. Maybe carbon fiber? West Marine published a very good book that had extensive information on building fg fuel tanks. Read it if you still have an open decision on fg. I know you gave up on plastic, but there are literally hundreds of thousands if not millions of molded plastic tanks made that generally hold corrosive commercial chemical products. They can be huge -- many thousands of gallons! The key is that they are rotomolded. That is, a female mold is made which is mounted on a machine that rotates the mold in all directions while hot liquified poly is injected into the tank. It spreads evenly due to the rotation method and the result is a seamless tank with uniform wall thickness, as thick as you want it to be. Want it thicker or thinner? Just add or leave out plastic. I wonder if you're dealing with somewhat similar designs between your port and starboard tanks. If so, you might be able to make a tank design with a universal fit and save bucks by inserting a filler mold piece inside the 150-gallon mold, ending up with a cheap mold for your smaller 120- or 130-gallon tank. You'll have to be clever with fill tubes and vents, but you guys will easily handle it, and I'm sure the tank company will have one or more staff engineers to help create a superb tank. You can weld poly with a hot air gun. A big consideration with rotomolded tanks is to design-in a robust mounting method, generally requiring that the tank be thicker wherever fasteners or straps are used to secure the tanks, and no square corners, especially around mounts or fasteners. You may also want to consider installing a third (much smaller) "Day Tank" to directly feed the engine clean, freshly filtered fuel to help avoid fuel contamination issues that likely will visit you in time, especially in rough wx when you're praying that the engine will keep running. Been there. Wow! Aluminum, when well protected and maintained, is a good choice, but I'm a bit lazy, so my choice would probably be mild steel tanks made by a commercial welding company with MIG/TIG modern welding equipment that has fabricated many diesel tanks over the years and has a good engineer on staff. The USCG regs for fuel tanks are rigorous and worth following carefully. All those rules came from investigations of fuel leaks and fires, thus every rule eliminates one or more failure points. I'm not so sure that steel tanks need to be as heavy as you may believe. Discuss with the tank guys their recommendation for steel thickness, perhaps using somewhat thinner steel (your tanks are relatively small when compared to those in offshore commercial boats). They all use internal stiffener ribs between the baffles, made of the same metal as the tank. Use lots of baffles. The baffles should be located just above the frames to further stiffen, strengthen, and support the tanks. You'll end up with well supported steel tanks that should last a lifetime. Be sure you use appropriate padding between the tank and the frames (and under all straps plus where the tanks mount (long ago we used rectangles of rubber cut from car-tire sidewalls). Please don't use metal fasteners to install those pads. One pair of new 150--gallon tanks lasted only 18-months because nails rusted holes into the tank bottom corners. It's a small thing but remember to have all your grounding tabs welded onto the tank in all the places where you'll need grounding wires (see the USCG regs) and add a few extras. Also, you ought to consider calling the Boeing Aircraft Company in Washington and find the manager who knows the most about installing new fuel tanks. They use aluminum tanks, but they also (at least they did in the past) coated every square millimeter of the inside of their tanks with a sealant coating that remains flexible as it seals perfectly. It permanently adheres to all interior metal surfaces, thus preventing all leaks from the inside out. The material is probably too soft for an external coating. It's hideous smelling stuff when applied, so if you decide to use it in your metal tanks, be careful and breathe via really good masks with forced ventilation. I assume you've given careful thought to how you'll remove condensed water from inside the tanks. Using the boat in colder waters with warm days will pump a lot of moisture-saturated air in and out of the tanks on a daily basis, leaving a lot of condensates behind. Keeping the tanks full of diesel will control most of it, but one of the best systems I've seen for this problem was a low condensate tank where all the condensed water was collected by gravity feed. The design of that tank allowed all water to be pumped out until fuel reached the low point and the drain valve. Sorry to be so wordy. If you can use any of the above great. Otherwise, you know where your delete key is. Cheers! Jim, S/V Aurora
I've been a carpenter for 45 years. I'm impressed with the level of detail on this project and the level of precision, and yes, I agree with the other posters regarding Patrick, his confidence and skills have made him a real asset. I hope he still has time for his pottery, he does great work there as well. What a life artist!
I was a plastics welder at a chemical company in the UK. We manufactured tanks that absolutely had to be leakproof, as some of the chemicals were dangerous and/or expensive (potassium gold cyanide being a classic example of both dangerous and expensive) All welds were tested with DC spark testers and then pressure tested with liquid, NOT GAS EVER. Some polypropylene comes with fibreglass mesh embedded in one side, which can then be reinforced with resin/fibre (after passing all leak tests) and ridged reinforcing could be added at this stage to prevent bowing, the resin fibre also took a fire-resistant coating well. The dodgy threads shown look as if no lube or ordinary oil was used as a lube. We used Swarfega hand cleaning gel as a tapping lube, used to give a really crisp cut thread in poly and uPVC. It looks like you were very unlucky with your choice of contractor, those welds didn't look too good.
I’ve built hundreds of fuel tanks for boats using aluminum and mild steel. None of which have I aloud out of my shop without a timely pressure test and in the last 25 +/- none year have came back with any leaks, corrosion or failures. If the tanks are built properly no matter what materials are used,that are used to make reliable and long lasting fuel tanks weight sounds like would only be the deciding factor! Hope this helps Leo and crew. Good luck from the east coast builder!💪🏼
You are quite right, how did they leave the factory like that? Leo could have named and shamed them (justifyably so). Being an English gentlemen, he decided against that, for which the manufacturer should be eternally grateful.
Over the years, as a welder, I have built literally hundreds of metal tanks and I agree with you whole heartedly about pressure testing each and everyone of them before they left my possession. No legitimate firm would ship any tank without pressure testing. I have also dabbled in plastic welding and I can honestly say that those welds were done by either someone who didn't care about their work or a complete novice and again I have to aske the question as why a legitimate fabricator would let those units out the door. As for using plastic for this application, I wouldn't do it. I would use stainless steel with a coating liner like POR-15 or KBS Gold Standard Tank Sealer inside. Some might question this but my rationale is simple. Stainless would have far fewer seams as it can be formed to shape in a sheet metal brake. I can also get stainless steel repaired and relined almost any where in the world should it become necessary. Plastic tanks, not so much.
Im a poly welder, i knew the second i saw it was welded with an extrusion gun this was going to leak.. the company who made this knew it was going to leak before they even started making it, and if they didnt this was the first tank theyve ever made.. the welds on it were embarrassing to look at for starters also , either they never welded a tank like this before, or they just completely didnt care..
I own a Nordhavn trawler, built in Taiwan and China. They’ve been building and installing fiberglass diesel tanks very successfully for years. I understand that they use a very specific type of frp, called cross-linked polyethylene (XPE). The tanks are strong, light, and they don’t sweat like aluminum, which reduces water build up in the bottom of the tank. You can have them built to fit in odd spaces, and the tanks will last forever!
Yes, why not consider fiberglass? Light and durable and you already have male molds in the form of the current leaky plastic tanks that are about to be trashed.
My own boat had bronze tanks from Navy surplus. Also watched the removal of large tanks from a big old wooden yawl, EVENING STAR, built in 1937. They were copper, fully baffled, in perfect shape, not a leak. They were being removed at the beginning of a renovation. Baffles are important. Fuel surging in a half empty large tank can do some pounding. Congratulations on your craftsmanship and thanks for spreading the knowledge. The work is stunning. Aloha Barry (the dog’s Dad)
I thought Leo said something in another episode about silicon bronze being one of the most corrosion resistant materials. Bronze or copper would certainly look better than plastic. Maybe relatively thin bronze could be used to save weight. Wood could be used to support the walls from too much flexing.
Leo, I’ve worked in marine environments a long time, and I understand your predicament with making a choice. My personal recommendation would be to go with a good quality mild steel. Aluminum is also good however. My issues with Aluminum are the potential for stress cracking, and of course galvanic action. Good luck with your decision, whichever way you choose. Just curious, did you consider dividing the tanks into more than two units? I know the strong impulse to save space on such a small boat, but one disadvantage is that it is holding up the work, and once installed it won’t be easily accessible. And in the event of a leak or puncture, the entire tank is unusable. With smaller ones, they could be individually Valverde, and join to a common line. In the event that you have an issue, just close the valve from that tank. This also gives you an extra bit of insurance against burning too much without notice. I’ve seen experienced operators have a lapse in attention and run tanks dry. And another benefit is separate storage. We have bought dodgy diesel before in a pinch, (and I bet you have too) and with a separated system, you can keep it from contaminating the rest of the known good fuel.
With four smaller tanks it also allows for the possibility of removing the tanks at a later time for inspection or repair. It's a lot easier to remove a small tank than a large one.
This approach appears so obvious (to a non-ship builder) that I am puzzled that Leo didn't go for it. Maybe there were other issues we don't know about? Perhaps that insane shape makes it dificult?!
@@paulhaynes8045 They would be very simple to fabricate. Aluminium can be brilliant but also extremely painful in a marine environment, when it starts to laminate with age and seawater/fuel gets into it it's pain in the ass to repair but Is doable. Just requires good maintenance. One of the pilot boats I was working on that had aluminium tanks actually started getting algae growth in the diesal on the aluminium which was braking off and filling the fuel system. Blocking up filters etc. I could not recommend aluminium tanks from my experience in the industry. Steel tanks I could but for the size of the vessel it's not worth the weight impact, I'd be going for plastics. Whether that's getting a custom mould made for rotational moulding or getting several smaller off the shelf tanks to place around the vessel for ballast like mentioned above.
shipping out tanks that are leaking .. everywhere ... that is just ... unacceptable (insert stronger word here) at least they are stepping up to repair them or give your money back (I'm with you going with "not up to marine standards" and "getting new tanks"
Totally dumbfounded they were not pressure tested before leaving the shop. The main purpose of any tank is to hold the intended contents. Astonishing the manufacturer indicated he stands behind the quality of the welds when they are obviously substandard… he must understand his statement doesn’t help his credibility. Hope the next attempt is successful.
I saw this and thought of you... Image: A sepia-effect photograph of Douglas Adams. “I remembered once, in Japan, having been to see the Gold Pavilion Temple in Kyoto and being mildly surprised at quite how well it had weathered the passage of time since it was first built in the fourteenth century. "I was told it hadn’t weathered well at all, and had in fact been burnt to the ground twice in this century. "“So it isn’t the original building?” I had asked my Japanese guide. "“But yes, of course it is,” he insisted, rather surprised at my question. "“But it’s burnt down?” “Yes.” “Twice.” “Many times.” “And rebuilt.” “Of course. It is an important and historic building.” “With completely new materials.” “But of course. It was burnt down.” “So how can it be the same building?” “It is always the same building.” "I had to admit to myself that this was in fact a perfectly rational point of view, it merely started from an unexpected premise. "The idea of the building, the intention of it, its design, are all immutable and are the essence of the building. "The intention of the original builders is what survives. The wood of which the design is constructed decays and is replaced when necessary. "To be overly concerned with the original materials, which are merely sentimental souvenirs of the past, is to fail to see the living building itself.” "― Douglas Adams, Last Chance to See"
My last boat had four 3000 gallon mild steel diesel tanks with baffle plates inside fore and aft as well as athwartships. Similar to yours, there's were corners that stuck down lower than the floor of the tank. About six inches up from those corners a 3/4"pipe bushing was welded and into that was threaded a brass ball valve with a 3/8" copper tube about seven inches long sticking out of it.. All of it was sealed up. The valve and tube were Telfoned and threaded into the bushing - the copper pipe pointing straight ahead, and the access panel was opened, in our case letting a man to enter, and the copper tube was bent downward into that lower corner, about 1/4- 3/8 inch off the bottom. Depending on our sailings; whether we went from tropics to temperate climes, those valves were cracked and a quart bottle used to capture what came out. Routinely there was one or two ounces of water, but sometimes a lot more. But we had a day tank so return from the engines went into the day tank and didn't heat up the storage tank. Three take aways from this: have a day tank, have surge bulkheads, collect the condensate from your storage tanks. Hope. this helps...
Brupeg’s mild steel fuel tanks are 50 years old and when we climb inside them we can read the builders writing still on the steel from 1974. Ours are 6mm steel and because of that they are stiff and don’t need as many baffles but you could easily build from 1.6mm mild and add in a number of baffles that become structural therefore creating a strong lightweight mild steel tank. With alloy it’s lighter but you still need to use heavier gauge plate compared to steel. The total weight savings are not as high as first thought
where i am from it is a rule of thumb the steel and aluminium have the same strength pund for pund if it is specd out the same. So it is more of a question of material properties than of weight.
Yes, so seeing that he is in a rush, the best answer is to get a quote for both aluminum and steel and pick the lighter of the two, because it will depend on what gauges of the metal are readily available, and if it is close then go with the steel because it is cheaper and easier to maintain.
Damn Leo, that sucks. I've built numerous fuel, water and hydraulic tanks from mild steel, aluminum and stainless for boats. If you budget allows it as well as the weight, I'd be going with stainless. Wish I were closer, I'd be building you a set just for the honour of doing it. My choice in order would be 1/8" stainless steel, (You mention corrosion in SS, if it's passivated after welding it'll prevent weld corrosion),10ga mild steel and then 3/16" aluminum all properly baffled and all with drains in the lowest point. No lugs for mounting, the tanks would have to fit in a cradle as it looks like yours are. Any lugs welded to the tanks would be a place for cracking to start. Any company that would build a set of tanks without testing is not a reputable company IMHO, you're a lot more civil than I would have been. Just noticed...no baffles neither, that's a lot of fluid to be moving and banging around when partially full....Mike
I do some work on Helicopters...They use #310 Stainless Steel...Less Pron to stress cracks from vibration, harder to fine After welding have the weld passivized. Mike Milburn is correct about the baffles...See if #310 S.S. is suitable for the marine application.
Having owned a 40 ' sailboat with a 84 gal. 1/8" SS fuel tank for the last 20 of its 44 years with no issues I would say go with stainless. It looks like you are planning on installing the inspection/pickups on the side. A bad idea. If you reduce the height to have the inspection port and hook ups on top not only will it save weight but make maintenance easier. Half full tanks cause condensation so if you don't plan on keeping them full opt for smaller.
Having seen a few steel tanks come out of boats, it's important to note that the ones that survive longest are the ones that are brimmed full pretty often. If you're going to be doing extended periods with less than half a fill in each, that can allow condensation to form on the top half of the tank, and rust to start. If they're brimmed every few journeys, like in a commercial boat etc, it's not an issue
That's what I was about to comment. I'm surprised I have not seen other comments to this "Granted I have not read every comment there being so few of them"😅
That is poor quality control from the tank manufacturers to say the least !! There’s never any compensation for lost time and money when the mistakes are not even your fault. Leo has the patience of a saint on top of all his other qualities 👍
Leo, I have just very recently finished the design and prototype manufacturing of aluminium diesel (actually kerosene) tanks for an aircraft, about 75 gal each. Although it may not sound like it, they have a lot in common with the tanks for Tally Ho. I obviously can't offer any experience with the longevity of this material under marine conditions but I can share some of the design considerations and experience from manufacturing. Based on this experience, aluminum tanks might be a great choice for Tally Ho. We decided to go with a welded aluminium structure, mainly for how leak proof the weld seams are when done right and for the inherent corrosion resistance. The tanks are made from annealed AlMg3 which welds nicely and is really forgiving to work with and pretty rigid once assembled. The alloy is really soft but does not deteriorate further around the welds. Our weld technician is rated for aluminium but had little practical experience, nevertheless he got the hang of it quickly. Thay may translate into ease of repair anywhere in the world once in service (apparently diesel tanks are welded completely full when repaired, although I would not want to be anywhere near that). As for the mass, our tank structure weighs about 90 lbs for 75 gal. The skin is from 2.5 mm sheetmetal which is stiffened with stringers and ribs on the inside. This was necessary due to the shape (over 3 m long) and the accelerations and safety factors required. The ribs also help spread the load from the four support brackets A stiffened structure may go a long way for your tank design as well, especially if you want to save weight and reduce slosh (no Idea if that is relevant in your case). It worked out nicely for us to design the sheetmetal structure in CAD to maximize use of the space available and to include the stiffeners and sloshing ribs. We fitted those to the outer skin with tabs and slots, that are included in the lasercut parts. After assembling the puzzle, the tabs were spot welded from the inside and through welded from the outside. If you decide to go with Alu, I would be glad to help out with more details from this project.
Homebuilt aircraft (think Vans) typically use alclad 2024-T3 alloy. If a builder lives near the ocean and wants more protection, a Sherwin Williams P60G2 coating or some other primer is used.
Absolutely agree with everything. You definitely want to have a couple of ribs in the center to stop the slosh, because with high seas pushing the boat around, that fuel can slam back and forth like a hammer, and depending on if you have an electric pump sticking down into the tank like a vehicle, that fuel sloshing around can break the pump, etc.. You can have holes all in your ribs to reduce weight. The oscillation of the fuel can also resonate and tip the boat more than you want it to possibly; (well, especially on much larger tanks- it's more essential on cruise ships and carriers, etc.). You can definitely weld on diesel tanks, (don't ever try that with gasoline though)... You can also use "pourable polymer" -- I thought that they could maybe use a pourable polymer in the plastic tanks and it would likely work well. But given how large they are, (and it didn't seem like those plastic tanks had ribs in them) -- I'm not sure if they would have held up to a full tank of diesel anyway, without the mounts breaking. I fully agree with you: Go with aluminum and paint it. With the interior, you could always empty them later and do the "pourable polymer" if needed; and if you're really worried about the bottom rotting out, you could always put in a false bottom in the tank so if it ever does corrode a hole into it, you'll still have a second outer bottom to give it a second lifespan. For me personally, I think I'd rather have 4 or even 6 smaller tanks-- so that if it does have a leak eventually, you can isolate that tank and reduce your losses, reduce the mess and not find yourself stranded because one little leak made you lose all your diesel fuel; to have some multiple redundancy built in I guess.. Sure it adds more fittings and more places to leak, but I think it's a better trade off than putting all your fuel in two large baskets; but that's just me.
Hi Leo I am a retired marine engineer and classic boat restorer Over 50 years experience I have found steel tanks to be the recommended choice in most applications and have used steel for septic tanks and fuel tanks the only time I have recommended plastic tanks is when petrol is being used because the water content causes rust Aluminium is fine but can suffer from electrolysis Stainless too can be preferred but can suffer long term with leaky seams when petrol is the fuel but have not had any problems when diesel is being used Now I don't know whether you have considered having a separate main fuel tank lower in the hull and an electric lift pump + a manual lift pump for emergency transfer then having a second tank to provide say 24 hours cruising higher in the boat Also such a system with a round baffled tank laid fore and aft would lower the potential of an unstable centre of gravity also diesel tanks will need cleaning periodically and therefore an access plate wold be advisable hope this helps I'm impressed with your excellent project management and enjoy the videos immensely best regards James Rawson
Hi Leo This episod was very interesting. I have been working with leak testing during my whole active working life. Especially leak testing of fueltanks within the automotive industry. Traditionally there have been steel tanks for petrol and diesel. Later came the plastic fuel tanks who where leighter an more durable. These tanks where originally made of plypropelene. The manufacturing process where blow moulding( high volume manufacturing). One of the problems with plastic fuel tanks is the high diffusion rate through the material. There are today some other plastic versions of fuel tanks but they are very expensive. For example co extruded tanks with seven differen layers of different plastic material. Among other a nylon material in the center layer who have a relatively low diffusion rate. I am glad you are locking for other material than the plastic alternative because the tanks would add some diesel smell into the boat. Today with the strong demands of hydro corbon escape from the car, fuel tank, the best material is stainless steel or other steel material with a zink coating. US fuel tanks for the green states ( california among other) havet theese steel materials in the automotive industy. Aluminum is a light material but it is difficult to make a leak proof weld. I would recommend stainless steel. Regarding leak rates on a diesel fueltank. Even very smal leaks will bring a leak who you do not see but it will come out in gas form. The pressure test is really a very rough test, mening it will detect very large leaks and not the small oance you need to find. The soap method is really effective so stick to that. A pressure of 0,025 to 0,05 athmosphere overpressure is enough. Using air or nitrogen is just fine. There are other detection methods but expensive. Please contact me if you have any questions. There are so mutch more to say on this subject. Thank you for sharing your nice job on Tally ho😀
I think because of the sea water stainless steel wouldn't be an option, you would need to go to duplex but the price for these would make them not practical unless a youtuber could make them.
I agree stainless is the go for tanks but Ali does just as good a job, never had a problem welding Ali tanks even repairs with diesel still in the tank. Not so keen welding petrol tanks though for obvious reasons.
@@edderube1247 welding duplex will be more time consuming. I would say that Tally Ho project is time consuming too. So I would go with duplex -) One might re-design the tanks in the way were the welding seams go. I don't like the way these plastic tanks were welded together.
Hi Leo and crew, We have a 30 ft 1975 cruiser on the Norfolk Broads in the UK, a far cry from the beautiful Tally Ho ! We have just had to replace our mild steel Diesel tank as it sprang a leak after 47 years in service, rusted through a seam!!! We have gone for Stainless Steel as a replacement, our tank is similar (but obviously smaller) in design to Tally Ho’s tanks in that they are contoured to the shape of her hull. Good luck with the rest of the project, I do most of the work on our boat ‘ Luna Aurora’ so I can to an to an extent appreciate the frustrations you have when things don’t go to plan. And I pick up loads of tips and ideas from you guys. Keep rolling boys and girls, she’s looking good so far. Thanks Graham
The way you dealt with the manufacturers of the fuel tanks was amazing. You role modelled the most superb civilised reaction to really disappointing product. Wow.
Agree and in aviation we.call it being Professional . The problem.with losing your rag is both side are loosers and you destroy the relationship, it doesn't really fix anything.
All airplanes have drainpoints in their tanks to avoid bacterial growth that will waste all the kerosine and fuelfilters quit rapidly. Diesel is not that much different from kerosine. A minimum amount of water in your tanks ( for example condensation) will sink to the lowest point , all what is needed for bacteria to multiply. For bacteria a pool of water is like an ocean for a person. Great job you are doing and take care.
The only positive I can think of on your tanks is that at least you know that your drawings/patterns are good to go, and fit, and at least you discovered the problem before you installed them. Great video Leo - Thank you for bringing us along.
Tip for using a holesaw in hardwood: drill a hole inside the perimeter that touches the outside edge of the hole. The saw dust will drop through the hole instead of being ground continually.
Not just wood. For metals, touch the saw to the work to mark a ring and then drill a slightly smaller ring of holes intersecting the kerf space, spaced maybe 30 or 40 mm apart. This will prevent swarf jamming the gullets, which is what heats the teeth (even with flood coolant because it can't get in). When run slowy enough in a mill or industrial strength drill press, this method can be used in mild steel up to 80 dia x 100 thick provided the saw is sharp
I am a retired diesel technician. I worked as a planner/estimator in the Philadelphia Naval Repair Facility Philadelphia Naval Shipyard in the 80's. PLANNER/ ESTIMATOR OF DIESEL ENGINES. The diesel tanks must be constructed as to repair them as easily as possible. One body construction is not preferable. Two bodies, one molded inner body seamless from a mold. The outer shell can be constructed by bolting it together. The molded body would be the inner. By doing this style you can have a drain plug on the outer body (prefer aluminium - weight - consious) this method of construction is more intensive. It solves to problems - 1. Better security for diesel leakage and 2. A second emergency tank if inner tank fails while underway. It would be easier to replace a molded inner tank instead of labor intensive new tech tank where there a seal seam lrakages as had happened in the tanks recieved. That is my suggestion. Your tanks are not as large as large ship tanks the process I described would be cost effective in repair.
In our boats, fleet of over 40, the larger of them, around 17 or so, all had bladders installed through the inspection hatch. The oldest, a 27 rib ex navy training vessle from the 30s or early 40s, is still running with her tanks that I helped install in the 80s.
Yep, why not keep those tanks and ask the manufacturer to provide suitable bladders that can be introduced via the existing or new access hatches - I presume there are no baffles in them?
Fuel Tanks: I work with large boats that deal with aluminum tanks for diesel storage. They are well manufactured and they are reliable. If you do the proper maintenance they'll last a long time. There's no reason to go crazy with different metal tanks. I think you can get lost doing the research. If water is a concern and boat building allows, you could add two fittings at the lowest point of the tanks, run to the center line of the boat with the sight glass and a petcock. You can drain out any residual water in the bottom of the tanks. Fuel water separators on pickup tubes on most diesel tanks are about an inch to inch and a half off the bottom of the tank and will only grab the small amount of water that is there. Love the videos, Love what you're doing with the boat. Looks beautiful. You have a wonderful group of people! Keep it up.
I would vote to go with good old mild steel. Coat it on the outside. The billions of automotive tanks in the world will agree with you, it is cheap but also has very reasonable performance. It can also be repaired by relatively low skilled labor. Good job guys! Great progress!
Greetings again Leo, if you utilise polypropylene and travel to the African shores you will find most diesel is manufactured with a high sulphur content and ethanol which unfortunately makes polypropylene very very brittle. Please consider another material. Thank you don’t want to alarm you. Lloyd from African shores.
You handled the tank debacle with class. I hate you have to hurry up and wait again. I love this channel because of the workmanship... For one thing. Thank you for the close views and descriptions. You have quite a talented crew. I could watch a two hour video of you all working. Take care and thank you for another excellent episode. Good luck with the tanks. ⛵❤️
Hello to all. I'm in the process of renovating a 1934 Saunders Roe gentlemens launch. We have recently reinstalled the original copper tanks. We couldn't fault them so....if it ain't broken.... Love the project. Ours is teak on rock elm which is why I started studying your build. Loads of ideas. Sublime attention to detail. Keep it up, Cheers Paul From Yorkshire
I think you handled and dealt with the tank issues honorably and very professionally. A real credit to you, lot can be learned from your outlook in life in general. A pleasure to watch your great videos as always. Cheers 👍
@@tavpierce1880 What about keeping the plastic tanks and putting fuel bladders inside them? If the bladder ever goes bad, it is much easier to replace too.
We had exactly the same discussion here. This incident was an indictment of that company. The tank shouldn't have gotten out the door without thorough testing and this tank suggests major problems with their manufacturing processes. Their response suggests that they have a company culture of test and repair. That is a potentially disastrous approach. Every time the product is sent back for repair additional manufacturing costs are incurred and a quality product is almost impossible with this approach because products that just barely pass the tests will be sent out to fail in the field. Leo was not without blame in this situation. From my perspective he took a risk on a technology that was not worth the risk given the long term cruising purposes he has in mind for the boat and he failed badly on vetting this company. Although my words might seem harsh on this I am a big fan of Leo and this channel. To have gotten this far with only a couple of failures like this, is very good IMO (I'm counting the keel fun as the other failure).
My aluminum tank says it was pressure tested at 3 PSI when it was manufactured/installed. I fabricated and installed some inspection hatches and matching backing rings when I had to clean it out, because the old inspection ports were only big enough for my wrist. When I was done I pressure tested it on my bench at 3 PSI and the aluminum tank bulged slightly, so the bulge on the plastic tanks is not surprising. Unfortunate that yours leaked. My aluminum tank is 40+ years old and it has held up great despite its battle with diesel bug and water.
Stainless tank 44 years old in my sailboat diesel of various fill level and purity still good I recently installed an inspection hatch and inside was fine apart from the sludge
Hi Leo, Go with mild steel tanks.4mm plate. Hot zinc the the exterior of the tanks once fabricated and then epoxy paint with a polyurethane finish coat. Important to include a spring loaded draw off cock (table "E" flange) at the lowest level to check for water/impurities - most don't do this in any tank, its "ship stuff". Since water sits in the bottom of the tank you can remove it, best checked every couple of weeks. Since it is not an integral tank as in a steel vessel you will not have a problem with condensation. I looked at a wooden fishing vessel we built 45 years ago, with tanks just like yours and was shocked at how well the port and starboard tanks looked - perfect condition! A fishing vessel has a lot more fuel turnover than you ever will. Don't worry about the extra weight over aluminium. While it might be three times, your vessel is heavy displacement anyway. The difference overall will be insignificant. Displacement equals comfort!
Right, the weight is about the weight of a heavier crew member and certainly less than the weight of 2 crew. It is also down lower in the boat not on the deck.
Even with Leos calm and cool demeanor I bet there was a moment when that wasn't so and I wouldn't blame him. Such a shame that such beautiful craftsmanship has to be delayed by such ineptitude
He was a real gentleman about it, but I could definitely hear a tremble in his voice that bespoke real disappointment and some righteous anger. I'm glad that the company at least promised a refund and hope it really comes. Quality problems like this don't fit with a prosperous business.
In process industry, we first fill the tanks with water and then pressurize with N2. The thought is that there is a lot less energy stored in the tank and things can’t go flying if you have a rupture.
It's the same way we pressure test pipe systems. If you fill them with air across an entire system, bad things happen if you have a blow out. It becomes a catastrophic failure. Doing a hydro test with N2 really minimizes the risk during a failure as the hydraulic pressure can immediately dissipate without making it a massive blow out.
@@1994kage67 I would not like to stand near that if it decided to blow, even with only 3psi. If you multiply the volume by the pressure, you get a significant amount of stored energy. More than enough to physically throw someone several meters.
@@WS102 It is not "immediate dissipation" that makes hydro tests safer. It is that fluids are a lot less compressible than gasses, and thus a LOT less energy is required to bring the same volume of fluid to a certain pressure than a gas. And so there is a lot less energy to release in case of a failure. Energy = force times distance; the forces (=pressures) are the same but with a fluid the distance is a LOT smaller -- ergo the energy is a LOT smaller. Less energy stored in the container means less energy can be imparted to the bits that fly off in case of a rupture.
@@TheEvertw Exactly, the resultant low volume of compressed air is insignificant compared to a fully compressed air only test. The level of kinetic energy generated is minor compared to charging an entire system with compressed air which has the potential to create major damage should the pipe or any fittings fail. Hydraulics make it possible to do it safely.
Emotional intelligence shows through again with the diesel tank issues experienced. Like others have said, well handled, Leo. You've chosen materials throughout the build for longevity of the boat. In my humble opinion for a sailing/working vessel, don't sacrifice proven longevity for the weight savings of a material that might have a short lifespan & amounts to 1.5 deckhands. Keep up the great build, craftsmanship, and content!
Decisions, decisions, decisions! But you're on top of it and are being careful with your engineering. Returning the plastic tanks is essential for you, and it's actually useful feedback for the manufacturer. Next time they will be more careful and will build a better and thoroughly tested tank. A fuel tank is not simply a bucket to store fuel. It is an integral part of a dynamic system and requires precise engineering and installation. (Check with the folks at Ford concerning their Pinto experience!) I'm going to guess that you will go with the time tested, steel tank, well-baffled, ventilated and with adequate and accessible drain clocks. No matter the material, or construction, keeping water out of your tanks and fuel lines is essential to basic operation, longevity and safety. And, while we are dealing with combustibles issues, I hope you will be equally careful about fire suppression in and around your fuel and engine compartments. The motor coach builders have some very nice systems in some of their vehicles, from which you could choose, or you can design your own. Either way will be costly, but fires happen. When they do, they need to be immediately put out. A motorcoach can be fully involved by fire within 2 minutes. Those folks have largely learned their lesson about putting a multi-million dollar machine at risk, due to a small fuel leak, overheated engine, or collision. You might check with you insurance underwriter, as well, to see what they may require, or recommend.
As well has his speaking of what he is doing. He at first was an immature youngster having fun and learning. Now, still having fun and learning, just much more mature. Nice watching him grow up.
These are to reenforce the wood structure, to avoid that it could crack in a natural wood defect that you don't see. Just like in a building outside walls, the old ones. As you can see, there are more skilled person's to explain to you more cientifically the purpose of putting those axes and bolts.
The bolts are actually to support the thinner cross grain sections that are the weakest part of the wood grain. Stress along the grain lines in the wood block are the strongest, (like the tree standing up) but force at 90 deg. to the grain lines will separate with less force. Hence the use of the bronze bolts is to introduce 90 deg reinforcement and added stress capability to those weaker areas.
Patrick always had skills. His transformation into shipwright is a testament to what happens when talented people are lucky enough to have experienced mentors who share, coach, and teach them the art of craftsmen ship.
Now that's a fact!!! We could all do similar things, but having a good guide is key.. n more importantly, is willing to admit u don't know it all along the way.. it's wonderful to pass on the knowledge obtained, but it's also nice to have a person to draw from their experiences......
Hi Leo, I have a few thoughts on the diesel tank problem, on large steel ships what usually writes the ship off to be an un-economical repair is the tank tops rusting out. The tops of the tank are vulnerable as condensation gathers there due to the air gap that is at atmospheric the bigger the gap the more condensation especially as Tally Ho's tanks are in a relatively warm place. I will cite HMS Britania, she had such a problem and it was more than financial. Anyhow it brings me around to the absolute bulletproof blow-molded ABS plastic used in the automotive trade by most volume manufacturers, it has got to be about the perfect material for the job as there are no welds involved, you have the molds already formed, but finding someone to blow them will be difficult, that's my thought, hope it helps. Cheers from the UK!
It is possible to "positive"-form those by blowing ABD into a form, or negative-forming by pulling the ABS into a form with vacuum. Problem here would be the "one-off" character of these tanks. The cost of a proper form to blow/vacuum the tank to does give reasonable results with high numbers of parts only.
I'm assuming maritime tanks must have a drain valve for the water accumulation like aircraft tanks? Take a look at the aluminum fuel tank on a Pitts Special, it's mounted to the fuse with straps, somewhat isolating it. Some of the examples on experimental amateur built Pitts S-1's are very crudely welded, yet despite the twisting of the fuselage during aerobatics, they hold up astonishingly well and also repair well
Really glad you detected the leaks prior to installation and filling , imagine how much of a mess that could have created . Leo , your attention to detail and quality control is very impressive . I performed Construction QC on large projects , and was amazed how often new equipment or materials were defective . Great woodworking & music , great video .
This is one of those great times to be documenting everything publicly and on camera! Also, that "great on hemorrhoids" joke absolutely killed me. Great work as always, guys. I love this channel.
Happy to see, but not surprised, that the folks at Google/RUclips recognize one of the top channels. And I agree, bring back the dislike button with counter. It’s helpful.
Leo, I’ve seen a few comments regarding aircraft bladder type tanks. It is definitely worth looking at how they would handle marine conditions. Probably comparable in weight to aluminium, but more durable. Back when I worked in motorsport we turned to the aviation industry for quite a few techniques, tools, materials and suppliers.
Retired A&P mechanic. Bladder type cells work good. And are tested on the workbench before installation into the cavity. They have aluminum flanges for rigid or flexible plumping. And most are laced into the cavity, installed though a oval manhole. Seldom have problems, if correctly installed. Can also removed and patched.
Wow lots of comments! My vote is for steel tanks. I would use cold rolled sheet as it will accept the epoxy much better without sandblasting. Hot rolled sheet really should have the scale removed by blasting before coating for maximum adhesion. Round aluminum tanks are really strong and durable but square or odd shaped aluminum tanks seem to fail way more often. You are really studious on these things so no matter what you choose I am sure it will be what is best for the boat long term.
Leo, you show what a true gentleman you are by how you handled the issues with the tanks. Many, many of us, would have been angry and thrown the manufacturer under the bus but despite a huge setback you kept your cool and forged forward. I could see how these skills would be of great value while captaining the boat under trying circumstances. My admiration gains through every episode. Cheers.
Hi Leo A masterful series. And I learned a lot from your journey.. The automotive industry uses aluminium which is anodised. Under-saddle motorcycle components are exposed to severe corrosion due to salted road conditions. Anodised aluminium is less likely to corrode than standard aluminium because it has a thicker oxide layer. Finally, anodised aluminium offers greater adhesion for adhesives and primers. This is because the oxide surface of anodised aluminium has deeper pores than that of standard aluminium. The pores are essentially holes in which adhesive, primers or liquids will flow when applied to the surface. As the anodized aluminium soaks up the liquids, it allows for greater adhesion.
For diesel tanks on offshore vessels, in my opinion, carbon steel. The external corrosion can be managed. One important item not talked about is the tank fittings. As you witnessed the concept of tapping NPT thread into any parent material will often go badly. Wall is too thin typically and requires reinforcement pad that will have a seam/flaw between shell and re-pad joint. All tank penetrations should use welded threaded fitting, ASTM flat thredolet is recommended to achieve proper thread engagement and reinforcement of tank shell for mechanical strength. For tank bottom fittings use a NPT size that allows sch 80 or sch 160 pipe nipples before your first shut off valve with sufficient ID for required fuel flow. Standard wall pipe nipples are too thin and weak at the threads for any accidental mechanical loads or an over zealous pipe fitter. Of course minimum guidance from ABYC H33: Diesel fuel systems. After all these years I don't mind diesel odor but many do and diesel has habit of weeping from poorly executed threads and fittings.
I made a plywood tank because I had run short on cash but I coated the inside with Epoxy and reinforced the seams and baffles with glass tape and then did the same on the outside. I have never had a drip of a leak and 42 years on there has been quite a lot of diesel pass through it. I have a drain cock at the bottom which I drain every few years. I wonder how much better a job one would do now with thinner ply impregnated with resin and using kevlar instead of glass. Neither expensive nor difficult and all so easy to fabricate to fit!
Think about glass fiber reinforced epoxy diesel tanks (or carbon fiber), you may be able to use the old plastic tanks as a mold (inside or out). You do have baffles designed in for added strength and anti-slosh, don't you? Also design in large access holes for inspection, maintenance and repair.
Hey Rich, i believe your fiberglass idea wont work at all, the tanks have access holes already so you dont need to tell and there are other ways to stop sloshing in a tank than baffles.
@@mm-hl7gh i love how nice and polite most of the audience in this channel is. this is constructive and it inspires me. my own me would have said something more like "hey rich, you sound a bit arrogant there, barking your bad ideas down from up on your high horse" but clearing it up like you did is just nicer. cheers!
These tanks fit well. Use them to make molds and then build fiberglass tanks. Well build fiberglass tanks will last a very long time. Keep the molds and spares can be made in the distant future.
With two tanks, particularly if you don’t see yourself running through a lot of diesel, you might install a fuel polishing system. You could then polish (clean) the fuel from one tank to the other and then back, removing sediment and moisture, thus keeping the fuel clean and reducing your concern about aluminum tanks.
Having a small buffer tank below that main ones, and the drain of these two at the lowest corner, so the water will always be at the small (probably plastic made) tank
Leo a Question...??? Have you investigated fuel tanks similar to aircraft? They have an aluminum structure of course but have a Goodyear Bladder insert, the bladders are custom built to fit several angles and have transfer tubes installed so you can remove the tanks due to age or leakage. We used them in many aircraft for the Military and they can be made to be self sealing as well, in case a bullet should penetrate the structure. The weight would be similar to you plastic tanks but will not leak like those did.....
I really love the way you dealt with the tank issue, and it is so different from what cable tv shows would have done and why I love watching content like this. Instead of milking the drama for all you could, you made the most of it and I actually learned a lot from the failure of those tanks and your exploration of other options that I wouldn’t have if everything worked well. And to me this is an example of how people should strive to act in frustrating moments. Despite obvious extreme frustration you didn’t dwell on it. I of course don’t know what happened off camera, and maybe there was lots of yelling and cursing, which is reasonable, but this incident is why I love this channel. (Also, hemorrhoid joke caught me off guard and was hilarious)
I don't know tanks in boats but I do suspect there's a tank manufacturer out there who'd be glad to fast track your project in order to be the subject of one of your excellent videos. It might even be a welded plastic guy who wants to do it right. Good things happen to good people. Every crisis has turned into an opportunity for you thus far. Your eager fans eagerly await the next episode!
Hey Leo - As always, excellent video and great project. With 35yrs. in the Marine Industry, and a former Boatyard Manager I have had many years of exposure to a variety of diesel fuel tanks...and without a doubt mild steel tanks with a proper epoxy coated exterior is the best option. As you said, most commercial boats use steel and there are tanks 80yrs. in service without problems. And if your calculations say that you only have a 200# difference between steel and aluminum ... then send that "fat guy" in the cockpit up to the foredeck!! 🤣🤣🤣
Hi Leo great job so far ...... I have worked on and built working boats for over 45 years, building altering and as a professional fisherman on both steel and aluminum with both types of tanks. Welded aluminum tanks are a bit weak in the weld department especially if 1/2 a tank of fuel can slop around in rough seas and are next to impossible to repair if a leak does appear. The one I have had a bit to do with were marine grade aluminum and usually made as a part of the hull. Besides the weight of steel tanks you have to be a bit careful if they are kept partially empty for extended periods of time as they can rust internally when the fuel coating dries out ( does take time thou and good filters can usually take care of that). What ever you decide to use make sure they are tested before any coating are put over them, in the case of steel preferably after sand blasting and before painting. Ps I have had to repair both steel and aluminum, the steel one had had diesel in it for years and wasn't a problem to weld where as the aluminum was new and had water put into it for testing and it took days with die grinders and welding to fix it.
In Australia, it’s fairly common in timber boats to have 316 grade stainless tanks. Id highly recommend them! We have almost a small sump on them so any water sediment can easily be drained off.
I agree, A4/316 is really really corrosion resistant. No experience of it's compatibility with diesel though. Really good diving equipment is made of it. Pricey though.
I've owned a 55' steel yacht for 16 years (in Australia) and it has 1400 litres of diesel spread across 5 ss tanks. The boat is 40 years old and the tanks are still holding together ... that said, the seam in one tank began to leak 9 years ago, which required me to cut the top of it open (after dismantling the starboard saloon furniture) in order to fit another slightly smaller ss tank inside it. So on reflection, I feel your dilemma, but would probably still go with ss again.
Such a shame that someone would send something out of their shop in this condition. Whomever was responsible for quality control in this facility should be held accountable for this disaster.
Leo, as a former long haul trucker, that spent a lot of time in and out of coastal ports, I would recommend the steel tanks. Yeah, there is the weight consideration, but you can balance out with ballast in the bow if need be, and it shouldn't raise the LWL on the hull by maybe an inch, two at best. The trick for keeping condensation rot at a minimum, even with a water drain in the bottom of the tanks, is to put a blown in liner inside the tanks when manufactured, before they're ever filled with any testing gasses or fuel/diesel. And, of course, as you've said, a sturdy epoxy paint or outer powder coating finish as well. The inner coating should be easy enough with your inspection ports as a lot of diesel truck tanks and motorcycle tanks inner liners are blown in through the filled neck. Just something to think about. Good luck. Oh, another consideration. Should anything get tossed about in rough seas, steel tanks would take a hit from a random object better than aluminum ones would. 🤔
If you're gonna blow in a liner, why not aluminum? Weight on a floating vehicle is a bit more sensitive than weight on a truck, and impact resistance should be handled by where they're installed, whereas most trucks' tanks are right out there ready to catch gravel.
The added weight is more complicated than just balancing it out with more weight at the other end of the boat. There is moment of inertia to think of as well... Take two boats of the same overall weight; one that has more of its weight concentrated amidships will ride better in a sea than one which is heavier at the bow and stern, even if the overall center of mass is the same in both boats.
@@danjelowitsch If the tanks already have cracks then any flexing over time will propagate the cracks. Like when your car window gets a tiny crack and then it spreads.
Leo I have designed equipment for the offshore oil industry for 30+ years and I can see that you have done your research. I would offer another option for the stainless alloy tank. In the last 15 years when corrosion and stress corrosion cracking is a concern the most logical materials are duplex or super duplex stainless steel. Besides the extreme corrosion resistance it is also more than twice as strong as regular stainless steel so the tank could be fabricated out of thinner material thus saving weight. Although many people are not familiar with this material it is quite readily available. I hope this helps some.
Hi Leo, just adding to the discussion on the best material for fuel tank. A 43' plywood boat was built over 40yrs ago in Fiji with a mild steel fuel tanks install. It lasted only 5yrs before it was replaced with marine grade plywood fuel tanks heavily coated with epiglass everdure wood sealer. The plywood fuel tanks are still in use today, 35yrs later.
The rain has finally come, the wildfire smoke is gone and a new Sampson Boat Co. video... happy birthday to me :) Edit: I vote aluminum since you're weight sensitive and I know you'll maintain it properly.
Hello Leo Every second Sunday morning a great pleasure to watch your videos with a good cup of coffee- all these years long! A comment to your tank-theme: it seems your plastictanks have no middleparts or sheets to withdraw the movement of the Diesel. If the tank is half filled and you are in heavy weather there is an extrem force running against the front and rear wall- plastic and even polypropylene will not resist very long -even your low pressure test shows a very high deformation, imagine this in a 5 seconds rhythm for hours and days! In my experience a Steeltank is the favorite, 5mm thickness, at least one sheet with holes, traditional or wig/tig-welded (no inert gas welding) from inside and outside and a good epoxycover- and don’t forget the wateroutlet at the bottom! Good luck and always a hand´s breadth underneath! Norbert from Germany
As soon as I heard you say that you bought welded plastic tanks, I was like, “NOOOOOOO!” We (water/wastewater treatment) have several that we use for NaOCL, NaOH, NaMnO4 (and others) and have had nothing but leaks from day one. The company is two states away, so we have to deal with the containment until they come out to repair them (which, has never went well - worse leaking). We do have a small, 100 gallon stainless steel tank that we use to refill emergency generators with, and has lasted for going on two decades now without any issues.
A tank like that is required to pass a pressure test post production and before delivery. I do a lot of tank testing in my field working on luxury yachts. The fact that those tanks were delivered in such condition is scarry.
@@AllFlimmits 2 thoughts: 1. Maybe the welds were somewhat faulty but passed inspection at the manufacturer and later on split open at the welds during shipping due to vibrations. 2. Maybe QC was only done with water, and no additional pressure, just like its use case would be, so none of the welds split open compared with the high amounts of pressure Leo put on there. But that begs the question if they would have lasted over the years.
Hi Leo, I'm half into a bottle wine in already, but when I saw these were welded plastic tanks my hair stood on end. I have been in aerospace engineering for 40+ years and would not trust those for fatigue when the fuel was sloshing around, so very well done to you team for the pressure test and I think you have had a near miss. That is no reflection on the manufacturer, I'm sure they made their best endeavour and plastic when moulded can be wonderful for this task. Your challenge is achieving maximum capacity for the available space and reliability. As stated, I would not go for aluminium either. For my input, I would investigate steel tanks made in Cor-Ten steel, as I'm sure you are aware steel yachts are made from it (I have zero experience). Put plenty of fully welded baffles in place too.
he needs to implement anti sloshing fins inside the tanks for more stability just like they do in airplanes ,he already has more range than he needs and i think its a fair trade !! stability for capacity
I have an S&S yawl that needed new diesel tanks and ended up using 3/16" or even 1/4" aluminum, it's been 16 years now and I forget which. The tanks have baffles. On the exterior, I had them Rino Coated (like they use on truck beds) and mounted on sleepers. The exterior of the tanks has held up well and look like the day I put them in. I worked on building the Matthew Turner in Sausalito, CA for a few years and enjoy your videos. Great Job!
To the manufacturer of the plastic tanks: You did understand that Leo has a famous RUclips channel. Your workmanship was gonna be front and center and yet you still sent them looking like this. I thank you for having intestinal fortitude to make it right and pay Leo back and cover shipping. You should take this as a learning experience and treat the construction of you products as if it is gonna be seen by thousands of people.
Hey when you get metal tanks, make sure they weld a plate and some eye hooks up there so you can move it around! Have another set of eye hooks screwed to the bottom of the deck so that you can use a rope to lift the tank into place using the sets if eye hooks . I.e. pull the tank up into pace by bringing the sets of eye hooks together.
When I saw the plastic diesel tanks they looked sub standard and I thought they would need to be supported on all sides to stop the sides bowing. I’d go for 5083 marine grade aluminium tanks. The thickness of the aluminium will be the key to longevity. I’d put the inspection lids/holes as high as possible if they can’t be on the top of the tank with near zero pressure from the fuel. I installed a 60 gallon aluminium diesel tank in a 71ft narrowboat here in England in the early 80’s which was expensive at the time but gave me no issues at all and looked pretty neat too. Love your channel and maybe one day you’ll sail into Gloucester docks so we can come and visit. 😎
Mast step piece looked like a lot of planning and work. Nicely done. Sorry to hear of the wasted time and effort on the tanks. Classy resolution, as expected, by Leo. Good to hear the company will be honest in resolving.
You can make molds for rotomolded tanks. It's quite easy. The labor and materials is basically the same as making a tank from AL. I have made large molds for a product I manufactured. Wall thickness was 5/16". The mold can also be used for a tank too. Also you can build the tank from alluminum and fill it with plastic and produce an inner liner that isn't removable. I'm in Vancouver BC and there is a company here that has the ability to produce large parts. If you would like to discuss this option send me a message. I'd like to help with your project and this might be just the opportunity.
Go with aluminum and add water socks to your routine maintenance schedule. In a nut shell they are a sock designed to sit at the bottom of a tank and absorb only water. Also a big aircraft company not far from you have been building fuel tanks for a long time. Maybe you can glean some knowledge from that industry. I have been watching for a long time and look forward to the weekly updates. Tally Ho!
The following coating spec or some equivalent would pretty much guarantee to nip corrosion in the bud: 1) Clean the tank and treat inside and out with Alodine 600: it's formulated for brush or spray, but because it's an aqueous solution it also works for dipping: the interior could be sprayed generously using a 90 degree spray nozzle on the end of a long tube, and any excess immediately tipped out and brushed on the outside before proceeding to brush fresh solution on the rest of the outside. This solution chemically converts the oxide layer. "...the film formed during the alodine process is not as thick as an anodizing layer. This film is a complex metal-chrome molecule film, and it later forms into a continuous gelatinous coating. It is the continuous gelatinous coating that prevents corrosion from happening by eliminating chemical processes." 2) Alodine does not resist abrasion, so it is used in (for example) the aircraft industry as a preparation for paint. The best paint works by chromate conversion, like Alodine, but zinc chromate paint is not very healthy (if precautions are inadequate) for those who use it day in day out so it's no longer used in the industry - some who have been around for a while will have seen the characteristic olive green colour before aluminium aero components got finish painted. The paint is still available, eg : www.aircraftspruce.com/catalog/cspages/ptiprimers.php?clickkey=17411, click on "Zinc Chromate Primer" 3) For ultimate corrosion and abrasion resistance, cover the paint with a proprietary truck bed liner, like Rhino Liner (which I believe is from Seattle), or with coal tar epoxy.
I omitted to say that Alodine would doubtless be sufficient inside the tank, but I suppose a gold-standard solution would prevent the ingestion of water vapour by sealing the tank filler, and using a nitrogen-filled bladder as a volume compensator (eg Pronal EXP inflatable separator) inside the tank, maintained a tad above maximum atmospheric pressure, in lieu of a breather! High spec coastal rescue boats, which are expected to experience inversion during operation, sometimes have something along these lines. Along with gravity operated closures to the air vents feeding the cabin and engine room forced ventilation systems, and similar units on the snorkels for the engine intakes. Such a system, for a cruising boat, would require refuelling to be done via an intermediate chamber (perhaps a day tank) from which it would be pumped into the storage tanks, to collapse the compensator bladder as well as prevent air entering the tank.
Hi Leo! If you decide to go the mild steel route, and are looking for a manufacturer, let me know. I run a fabrication shop in Indiana, and if you have DXF files of the design, I could have these made very quickly (5-8 days) and could do for cost just so I can say our company made something for this amazing project. We have cnc lasers and some amazing welders. We do mainly MIG welding , which isn’t the best welding application for aluminum but we do have aluminum laser cutting and aluminum mig welding capabilities…. We have made many tanks for very large international companies which I could share with you in a private message. Obviously we would pressure test them in house before ever shipping them. Let me know! I take as much pride in our work as you do yours. Love the project, have followed from the beginning.
Get this man up top in the comments right now
What a legend!!
Thank you so much David! And sorry for the delay, I only just saw this comment. I think we are on track with a good plan now but I really appreciate the offer and will be back in touch if if falls though! Thanks again
Much better than welded plastic.
Steel is real.
Hey Leo. THIS IS IMPORTANT. IF YOU READ NOTHING ELSE, PLEASE READ THE PART THAT ARE WRITTEN IN CAPS. I can finally give you advice from my expertise that will help.
I was lucky enough to happen along your podcasts at episode #3. So after quickly catching up with #1 and #2 I've been completely fascinated by your wherewithal, knowledge, tenacity, perseverance and your even-keeled personality. I haven't missed an episode since. Not Australian, but I have to say, "Good on ya, Mate!"
Now, coming from an aviation background it never seemed possible that I could ever be of assistance with anything you are doing, but now I can. SO PLEASE HEAR THIS... STOP WRAPPING UP YOUR POLY TANKS TO SEND BACK. KEEP THEM. THEY ARE ABSOLUTELY BEAUTIFUL IN BOTH FORM AND FUNCTION. ALL YOU NEED TO DO IS SEND THE SPECS TO AN AVIATION FUEL BLADDER MAKING COMPANY AND YOU CAN USE THOSE TANKS AS-IS AND THE BLADDER WILL SUPPLY ALL THE LEAK-PROOFING YOU WILL EVER NEED - FOREVER! Fuel bladders in the wings of airplanes is as common as wings. As well, should there ever be any leakage (hard to imagine - but accidents can happen), the bladder is relatively easy to remove and replace (always keeping ease of maintenance in mind). Since leakage through the plastic would no longer be a problem, it would be easy to cut an access hatch in the top of each plastic tank in order to facilitate installing, and possibly removing and replacing the bladder should it be needed at some time in the future. I HAVE EVERY CONFIDENCE THAT THIS WOULD WORK REALLY WELL AND WOULD BE, BY FAR, THE MOST EXPEDIENT AND EFFICIENT WAY TO SOLVE THIS PROBLEM. AS WELL, IT MAY ALSO BE THE LEAST COSTLY. YOU COULD EVEN HAVE TWO BLADDERS PER TANK MADE AND THEN BE ABLE TO REPLACE A BLADDER IMMEDIATELY AND ON-THE-GO, SHOULD WORSE COME TO WORSE FOR SOME REASON.
I'm grateful for the opportunity to finally be able to provide something from my expertise in order to help you with something in your expertise. I'm really looking forward to the time when I'll be able to follow you through some of your early voyages in this wonderful boat (though you haven't mentioned this prospect yet.) BTW: With enough research and ingenuity, it would be possible that you, or your team, could actually make custom bladders yourselves. Ambitious, but a do-able thing. Getting proficient at heat sealing and gluing isn't an impossible task at all. After all, the bladder doesn't have to hold any pressure at all. It's just a fuel barrier. Practice a little bit on small scale stuff and I'm confident you would do fine. Will Robertson
Not a bad idea actually!
Hi Will, can the bladders be fitted with baffles?
45 years in the aviation industry pilot/ame fuel bladders are absolutely the way to go period I can attest to personal experience including ballistic self sealing tanks used in the military.
Seems the use of bladders in aircraft is a tried and true technology, how does this option go cost wise?
I was thinking on these lines. Integral aliminumen tanks in no bladder tanks we used to add Prist to the fuel (Jet A1) it mixed with any water in the fuel and supposedly made the water an inhibiter, It's a long time since I worked with aircraft so it may not be used these days. I'm sure someone will know. LOL
I am a machinist many years thinking outside the box. So I researched your tank problem and I have a suggestion. As you know a leaking fuel tank has a serious accessibility problem. I see where you are installing your tanks. Consider using 8 X Aluminum Coal Tar Epoxy double coated tanks, 4 x each side. This will reduce the size and allow removal of individual leaking tanks later without ripping your precious Tally Ho to pieces removing a monster size tank. Leaking tanks can be emptied and bypassed at sea until it is more convenient to service. Love you ALL.
That idea makes good sense. Even just breaking the two large tanks down to 4 or 6 smaller tanks. The ease and convenience of repairs or replacement would justify the weight of the additional material. They could be secured to one another to minimize any wear from movement.
@@LesFelts Yes, smaller tanks would be better from a maintenance view for sure. Also when the Boat is moving around in the sea less diesel will move around in the tanks with less internal forces. So this solution seems the way to go I think. Perhaps even a good way to have control of how much diesel is left at a given time will be easier to see.
Being a retired Plumber--PipeFitter Welder and Welding my whole life I would Never use Plastic Tanks.... The Joints always fail over time 🙄..
What a great idea. Smaller tanks prevent sloshing. Large tanks usually would have a slosh baffle, but joining smaller tanks prevents the need for those. I didn't see any outline of slosh baffles in those plastic welded tanks
Big tanks for bulk transport, small tanks for survivability.
Rather than plumbing each tank to the next, run a single feed line with T joints and valve to each tank.
So any tank can be isolated and removed without effecting the function of the overall fuel storage.
The catch, it will increase weight and reduce capacity.
The manufacturer of those tanks should have pressure-checked them before shipping. Full stop! You're too nice and very diplomatic, Leo.
Hard to understand why they didn't do quality control check out of tanks prior to shipping. Totally unacceptable....😞😞😞
You get more with honey than vinegar, if you want your money back. Getting worked up and busting a vein over it, doesn't do anyone any good.
Honestly the silicone around the cover screws was a tell on the quality. What a mess.
They definitely were not fit for purpose! No sale, for sure.
They may have and they may have met the standard for diesel fuel. Nitrogen is a tiny atom and can fit through gaps that no other atom would fit through. So while it may leak with nitrogen, there could be zero chance of diesel or even other gaseous atoms leaking.
Stoked to be a part of the crew! Great video, as always, Leo.
21:04 you're hand hammering with the mallet inches away!! Those hands will be upset with you in the years to come! Haha use the tools! Anyways nice to see you enjoy the project and the fun environment 🙂
Stop kissing up to the boss. 😂😂😂😂.
Always great to see new faces aboard Nic. I hope you enjoy your time and also mutually learn a lot from Leo, his great crew and each other. I am sure you will be a great asset to the team.
Really cool to see two separate craftsman I have watched before come together. It was a bit like an Avengers movie. All you need now is Mr chickadee making some Poplar binnacle or something like that.
As an old(very old) Royal Navy shipwright (or artificer as we became) It makes me so happy to see you young engineers and volunteers keeping the old traditional working skills alive. Well done all of you.
"Artificer" can also describe my abilities with computers. I can still program for DOS in assembly using MS Debug as an assembler instead of using a compiler. Translation: I can make my own tools for any need in the old ship by using a pocket knife and a file.
I am always glad to know other "artificers" are still around.
Ahh yes the old steam computers ;) :D @@leathernluv
Hi Leo. First, thanks for all your videos. I'm a mariner and sailor and grew up on the Pacific Ocean. I've worked in and on many boats and have owned a few sailboats. My wife and I wife sailed our Morgan 382 more than 25,000 miles south from San Francisco along California and the Pacific coast of Mexico, visiting many of the anchorages between there and those along Central American countries until we reached the Panama Canal. Then it was off to the Galapagos Islands for a couple months. We cruised through all the South Pacific islands we could find, finally arriving in New Zealand/Australian waters with tropical cyclones threatening north of us. We eventually swallowed the hook after a couple great years down under. We had the same Westerbeke engine as you -- you made a good choice.
Regarding the fuel tank questions you have, if you do it correctly, virtually all the materials you mentioned will work. I have personal experience with Aluminum, Fiberglass, and Mild Steel. The big thing with aluminum is corrosion, not just from salt water, but also from any galvanic dissimilar metals that come into contact with aluminum. A bit of spilled mercury or copper bits resting on aluminum in salt air will hole it. Fiberglass is fine. I've had both solid fiberglass and fiberglass over marine plywood tanks. Made carefully, they don't leak, but I sense that the ply + glass is weaker than solid fg. Maybe carbon fiber? West Marine published a very good book that had extensive information on building fg fuel tanks. Read it if you still have an open decision on fg.
I know you gave up on plastic, but there are literally hundreds of thousands if not millions of molded plastic tanks made that generally hold corrosive commercial chemical products. They can be huge -- many thousands of gallons! The key is that they are rotomolded. That is, a female mold is made which is mounted on a machine that rotates the mold in all directions while hot liquified poly is injected into the tank. It spreads evenly due to the rotation method and the result is a seamless tank with uniform wall thickness, as thick as you want it to be. Want it thicker or thinner? Just add or leave out plastic.
I wonder if you're dealing with somewhat similar designs between your port and starboard tanks. If so, you might be able to make a tank design with a universal fit and save bucks by inserting a filler mold piece inside the 150-gallon mold, ending up with a cheap mold for your smaller 120- or 130-gallon tank. You'll have to be clever with fill tubes and vents, but you guys will easily handle it, and I'm sure the tank company will have one or more staff engineers to help create a superb tank. You can weld poly with a hot air gun.
A big consideration with rotomolded tanks is to design-in a robust mounting method, generally requiring that the tank be thicker wherever fasteners or straps are used to secure the tanks, and no square corners, especially around mounts or fasteners. You may also want to consider installing a third (much smaller) "Day Tank" to directly feed the engine clean, freshly filtered fuel to help avoid fuel contamination issues that likely will visit you in time, especially in rough wx when you're praying that the engine will keep running. Been there. Wow!
Aluminum, when well protected and maintained, is a good choice, but I'm a bit lazy, so my choice would probably be mild steel tanks made by a commercial welding company with MIG/TIG modern welding equipment that has fabricated many diesel tanks over the years and has a good engineer on staff. The USCG regs for fuel tanks are rigorous and worth following carefully. All those rules came from investigations of fuel leaks and fires, thus every rule eliminates one or more failure points. I'm not so sure that steel tanks need to be as heavy as you may believe. Discuss with the tank guys their recommendation for steel thickness, perhaps using somewhat thinner steel (your tanks are relatively small when compared to those in offshore commercial boats). They all use internal stiffener ribs between the baffles, made of the same metal as the tank. Use lots of baffles. The baffles should be located just above the frames to further stiffen, strengthen, and support the tanks. You'll end up with well supported steel tanks that should last a lifetime. Be sure you use appropriate padding between the tank and the frames (and under all straps plus where the tanks mount (long ago we used rectangles of rubber cut from car-tire sidewalls). Please don't use metal fasteners to install those pads. One pair of new 150--gallon tanks lasted only 18-months because nails rusted holes into the tank bottom corners.
It's a small thing but remember to have all your grounding tabs welded onto the tank in all the places where you'll need grounding wires (see the USCG regs) and add a few extras. Also, you ought to consider calling the Boeing Aircraft Company in Washington and find the manager who knows the most about installing new fuel tanks. They use aluminum tanks, but they also (at least they did in the past) coated every square millimeter of the inside of their tanks with a sealant coating that remains flexible as it seals perfectly. It permanently adheres to all interior metal surfaces, thus preventing all leaks from the inside out. The material is probably too soft for an external coating. It's hideous smelling stuff when applied, so if you decide to use it in your metal tanks, be careful and breathe via really good masks with forced ventilation.
I assume you've given careful thought to how you'll remove condensed water from inside the tanks. Using the boat in colder waters with warm days will pump a lot of moisture-saturated air in and out of the tanks on a daily basis, leaving a lot of condensates behind. Keeping the tanks full of diesel will control most of it, but one of the best systems I've seen for this problem was a low condensate tank where all the condensed water was collected by gravity feed. The design of that tank allowed all water to be pumped out until fuel reached the low point and the drain valve.
Sorry to be so wordy. If you can use any of the above great. Otherwise, you know where your delete key is.
Cheers!
Jim, S/V Aurora
How would you fit the baffles which are vital in any tank that is being thrown about in a boat if you are fabricating using the rotomoulding process?
❤
I've been a carpenter for 45 years. I'm impressed with the level of detail on this project and the level of precision, and yes, I agree with the other posters regarding Patrick, his confidence and skills have made him a real asset. I hope he still has time for his pottery, he does great work there as well. What a life artist!
I was a plastics welder at a chemical company in the UK. We manufactured tanks that absolutely had to be leakproof, as some of the chemicals were dangerous and/or expensive (potassium gold cyanide being a classic example of both dangerous and expensive) All welds were tested with DC spark testers and then pressure tested with liquid, NOT GAS EVER. Some polypropylene comes with fibreglass mesh embedded in one side, which can then be reinforced with resin/fibre (after passing all leak tests) and ridged reinforcing could be added at this stage to prevent bowing, the resin fibre also took a fire-resistant coating well. The dodgy threads shown look as if no lube or ordinary oil was used as a lube. We used Swarfega hand cleaning gel as a tapping lube, used to give a really crisp cut thread in poly and uPVC. It looks like you were very unlucky with your choice of contractor, those welds didn't look too good.
I’ve built hundreds of fuel tanks for boats using aluminum and mild steel. None of which have I aloud out of my shop without a timely pressure test and in the last 25 +/- none year have came back with any leaks, corrosion or failures.
If the tanks are built properly no matter what materials are used,that are used to make reliable and long lasting fuel tanks weight sounds like would only be the deciding factor! Hope this helps Leo and crew. Good luck from the east coast builder!💪🏼
Sounds like you should touch base with Leo. How fast can you make 2 tanks of this size?
You are quite right, how did they leave the factory like that? Leo could have named and shamed them (justifyably so). Being an English gentlemen, he decided against that, for which the manufacturer should be eternally grateful.
@@johncollier608 That might change if they fail to refund in full.
Over the years, as a welder, I have built literally hundreds of metal tanks and I agree with you whole heartedly about pressure testing each and everyone of them before they left my possession. No legitimate firm would ship any tank without pressure testing. I have also dabbled in plastic welding and I can honestly say that those welds were done by either someone who didn't care about their work or a complete novice and again I have to aske the question as why a legitimate fabricator would let those units out the door.
As for using plastic for this application, I wouldn't do it. I would use stainless steel with a coating liner like POR-15 or KBS Gold Standard Tank Sealer inside. Some might question this but my rationale is simple. Stainless would have far fewer seams as it can be formed to shape in a sheet metal brake. I can also get stainless steel repaired and relined almost any where in the world should it become necessary. Plastic tanks, not so much.
Im a poly welder, i knew the second i saw it was welded with an extrusion gun this was going to leak.. the company who made this knew it was going to leak before they even started making it, and if they didnt this was the first tank theyve ever made.. the welds on it were embarrassing to look at for starters also , either they never welded a tank like this before, or they just completely didnt care..
I own a Nordhavn trawler, built in Taiwan and China. They’ve been building and installing fiberglass diesel tanks very successfully for years. I understand that they use a very specific type of frp, called cross-linked polyethylene (XPE). The tanks are strong, light, and they don’t sweat like aluminum, which reduces water build up in the bottom of the tank. You can have them built to fit in odd spaces, and the tanks will last forever!
Yes, why not consider fiberglass? Light and durable and you already have male molds in the form of the current leaky plastic tanks that are about to be trashed.
I was also wondering about fiberglass. But I am not really qualified to comment.
Composites make sense. Just be sure to use vinylester resin, if there is any ethanol in the fuel.
Nordhavn, amazing brand! And they know what they are talking about. Fibreglass is the best for these tanks. I was surprised Leo did not mention it.
FRP = Fiberglass Reinforced Plastic.
My own boat had bronze tanks from Navy surplus. Also watched the removal of large tanks from a big old wooden yawl, EVENING STAR, built in 1937. They were copper, fully baffled, in perfect shape, not a leak. They were being removed at the beginning of a renovation.
Baffles are important. Fuel surging in a half empty large tank can do some pounding.
Congratulations on your craftsmanship and thanks for spreading the knowledge. The work is stunning.
Aloha
Barry (the dog’s Dad)
I thought Leo said something in another episode about silicon bronze being one of the most corrosion resistant materials. Bronze or copper would certainly look better than plastic. Maybe relatively thin bronze could be used to save weight. Wood could be used to support the walls from too much flexing.
Is the Evening Star work halted indefinitely at this point?
Leo, I’ve worked in marine environments a long time, and I understand your predicament with making a choice. My personal recommendation would be to go with a good quality mild steel. Aluminum is also good however. My issues with Aluminum are the potential for stress cracking, and of course galvanic action. Good luck with your decision, whichever way you choose. Just curious, did you consider dividing the tanks into more than two units? I know the strong impulse to save space on such a small boat, but one disadvantage is that it is holding up the work, and once installed it won’t be easily accessible. And in the event of a leak or puncture, the entire tank is unusable. With smaller ones, they could be individually Valverde, and join to a common line. In the event that you have an issue, just close the valve from that tank. This also gives you an extra bit of insurance against burning too much without notice. I’ve seen experienced operators have a lapse in attention and run tanks dry. And another benefit is separate storage. We have bought dodgy diesel before in a pinch, (and I bet you have too) and with a separated system, you can keep it from contaminating the rest of the known good fuel.
Well said. Easy to think we obsess about tanks. Until you've had to deal with all this. Those are two darn big tanks, imo.
With four smaller tanks it also allows for the possibility of removing the tanks at a later time for inspection or repair. It's a lot easier to remove a small tank than a large one.
S/V Seeker has multiple tanks for this reason also to use as ballast via moving fuel around to different tanks.
This approach appears so obvious (to a non-ship builder) that I am puzzled that Leo didn't go for it. Maybe there were other issues we don't know about? Perhaps that insane shape makes it dificult?!
@@paulhaynes8045 They would be very simple to fabricate.
Aluminium can be brilliant but also extremely painful in a marine environment, when it starts to laminate with age and seawater/fuel gets into it it's pain in the ass to repair but Is doable. Just requires good maintenance.
One of the pilot boats I was working on that had aluminium tanks actually started getting algae growth in the diesal on the aluminium which was braking off and filling the fuel system. Blocking up filters etc.
I could not recommend aluminium tanks from my experience in the industry.
Steel tanks I could but for the size of the vessel it's not worth the weight impact, I'd be going for plastics.
Whether that's getting a custom mould made for rotational moulding or getting several smaller off the shelf tanks to place around the vessel for ballast like mentioned above.
shipping out tanks that are leaking .. everywhere ... that is just ... unacceptable (insert stronger word here) at least they are stepping up to repair them or give your money back (I'm with you going with "not up to marine standards" and "getting new tanks"
Not up to tank standards?
American made lol
@@ReinoGoo the standard, not to leak, do they ? Yes . Then they are not of useable quality !!!
Totally dumbfounded they were not pressure tested before leaving the shop. The main purpose of any tank is to hold the intended contents. Astonishing the manufacturer indicated he stands behind the quality of the welds when they are obviously substandard… he must understand his statement doesn’t help his credibility. Hope the next attempt is successful.
I saw this and thought of you...
Image: A sepia-effect photograph of Douglas Adams.
“I remembered once, in Japan, having been to see the Gold Pavilion Temple in Kyoto and being mildly surprised at quite how well it had weathered the passage of time since it was first built in the fourteenth century.
"I was told it hadn’t weathered well at all, and had in fact been burnt to the ground twice in this century.
"“So it isn’t the original building?” I had asked my Japanese guide.
"“But yes, of course it is,” he insisted, rather surprised at my question.
"“But it’s burnt down?”
“Yes.”
“Twice.”
“Many times.”
“And rebuilt.”
“Of course. It is an important and historic building.”
“With completely new materials.”
“But of course. It was burnt down.”
“So how can it be the same building?”
“It is always the same building.”
"I had to admit to myself that this was in fact a perfectly rational point of view, it merely started from an unexpected premise.
"The idea of the building, the intention of it, its design, are all immutable and are the essence of the building.
"The intention of the original builders is what survives. The wood of which the design is constructed decays and is replaced when necessary.
"To be overly concerned with the original materials, which are merely sentimental souvenirs of the past, is to fail to see the living building itself.”
"― Douglas Adams, Last Chance to See"
My last boat had four 3000 gallon mild steel diesel tanks with baffle plates inside fore and aft as well as athwartships. Similar to yours, there's were corners that stuck down lower than the floor of the tank. About six inches up from those corners a 3/4"pipe bushing was welded and into that was threaded a brass ball valve with a 3/8" copper tube about seven inches long sticking out of it.. All of it was sealed up. The valve and tube were Telfoned and threaded into the bushing - the copper pipe pointing straight ahead, and the access panel was opened, in our case letting a man to enter, and the copper tube was bent downward into that lower corner, about 1/4- 3/8 inch off the bottom. Depending on our sailings; whether we went from tropics to temperate climes, those valves were cracked and a quart bottle used to capture what came out. Routinely there was one or two ounces of water, but sometimes a lot more. But we had a day tank so return from the engines went into the day tank and didn't heat up the storage tank. Three take aways from this: have a day tank, have surge bulkheads, collect the condensate from your storage tanks. Hope. this helps...
Brupeg’s mild steel fuel tanks are 50 years old and when we climb inside them we can read the builders writing still on the steel from 1974. Ours are 6mm steel and because of that they are stiff and don’t need as many baffles but you could easily build from 1.6mm mild and add in a number of baffles that become structural therefore creating a strong lightweight mild steel tank. With alloy it’s lighter but you still need to use heavier gauge plate compared to steel. The total weight savings are not as high as first thought
where i am from it is a rule of thumb the steel and aluminium have the same strength pund for pund if it is specd out the same. So it is more of a question of material properties than of weight.
Yes, so seeing that he is in a rush, the best answer is to get a quote for both aluminum and steel and pick the lighter of the two, because it will depend on what gauges of the metal are readily available, and if it is close then go with the steel because it is cheaper and easier to maintain.
What about corten steel?
Dame and Jess, great to see my other favorite channel doing a cross-over!
Perhaps when you consider it will be mostly at least half if not 3/4 full of diesel then the weight of the empty tank is not such a factor.
Watching Patrick's skillset improve over time has been a pleasure to see
Damn Leo, that sucks. I've built numerous fuel, water and hydraulic tanks from mild steel, aluminum and stainless for boats. If you budget allows it as well as the weight, I'd be going with stainless. Wish I were closer, I'd be building you a set just for the honour of doing it.
My choice in order would be 1/8" stainless steel, (You mention corrosion in SS, if it's passivated after welding it'll prevent weld corrosion),10ga mild steel and then 3/16" aluminum all properly baffled and all with drains in the lowest point. No lugs for mounting, the tanks would have to fit in a cradle as it looks like yours are. Any lugs welded to the tanks would be a place for cracking to start.
Any company that would build a set of tanks without testing is not a reputable company IMHO, you're a lot more civil than I would have been. Just noticed...no baffles neither, that's a lot of fluid to be moving and banging around when partially full....Mike
I do some work on Helicopters...They use #310 Stainless Steel...Less Pron to stress cracks from vibration, harder to fine After welding have the weld passivized. Mike Milburn is correct about the baffles...See if #310 S.S. is suitable for the marine application.
Having owned a 40 ' sailboat with a 84 gal. 1/8" SS fuel tank for the last 20 of its 44 years with no issues I would say go with stainless. It looks like you are planning on installing the inspection/pickups on the side. A bad idea. If you reduce the height to have the inspection port and hook ups on top not only will it save weight but make maintenance easier. Half full tanks cause condensation so if you don't plan on keeping them full opt for smaller.
@@rmsflorida 316L is the most corfosino resistant
i love how every little piece of the entire ship is a work of art. just that little mast step was gorgeous.
yes it is a shame to have to cover that beautiful purple heart with paint though.
@@weird1600 word
@@weird1600 Purple heart doesn't stay purple forever, though (sadly).
@@ep1981 still a beautiful piece of wood!
Having seen a few steel tanks come out of boats, it's important to note that the ones that survive longest are the ones that are brimmed full pretty often. If you're going to be doing extended periods with less than half a fill in each, that can allow condensation to form on the top half of the tank, and rust to start. If they're brimmed every few journeys, like in a commercial boat etc, it's not an issue
That's what I was about to comment. I'm surprised I have not seen other comments to this "Granted I have not read every comment there being so few of them"😅
That is poor quality control from the tank manufacturers to say the least !!
There’s never any compensation for lost time and money when the mistakes are not even your fault.
Leo has the patience of a saint on top of all his other qualities 👍
You are correct that IS A CRAP JOB.
@@philipstreechon4523 As soon as I saw how they were delivered - no packaging and barely held on the pallet I was worried.
I want to kiss him too, but he doesn't even notice me
Well, he has patience on camera. I bet he was cussing like a sailor off camera, LOL. I would have been more than cussing......
Hard to believe the company didn't even test the tanks for leaks before shipping. Not a good moniker for the company whoever they are.
Leo, I have just very recently finished the design and prototype manufacturing of aluminium diesel (actually kerosene) tanks for an aircraft, about 75 gal each. Although it may not sound like it, they have a lot in common with the tanks for Tally Ho. I obviously can't offer any experience with the longevity of this material under marine conditions but I can share some of the design considerations and experience from manufacturing. Based on this experience, aluminum tanks might be a great choice for Tally Ho.
We decided to go with a welded aluminium structure, mainly for how leak proof the weld seams are when done right and for the inherent corrosion resistance. The tanks are made from annealed AlMg3 which welds nicely and is really forgiving to work with and pretty rigid once assembled. The alloy is really soft but does not deteriorate further around the welds. Our weld technician is rated for aluminium but had little practical experience, nevertheless he got the hang of it quickly. Thay may translate into ease of repair anywhere in the world once in service (apparently diesel tanks are welded completely full when repaired, although I would not want to be anywhere near that).
As for the mass, our tank structure weighs about 90 lbs for 75 gal. The skin is from 2.5 mm sheetmetal which is stiffened with stringers and ribs on the inside. This was necessary due to the shape (over 3 m long) and the accelerations and safety factors required. The ribs also help spread the load from the four support brackets
A stiffened structure may go a long way for your tank design as well, especially if you want to save weight and reduce slosh (no Idea if that is relevant in your case). It worked out nicely for us to design the sheetmetal structure in CAD to maximize use of the space available and to include the stiffeners and sloshing ribs. We fitted those to the outer skin with tabs and slots, that are included in the lasercut parts. After assembling the puzzle, the tabs were spot welded from the inside and through welded from the outside.
If you decide to go with Alu, I would be glad to help out with more details from this project.
Nice write up. I vote for your team to get the job.
Homebuilt aircraft (think Vans) typically use alclad 2024-T3 alloy. If a builder lives near the ocean and wants more protection, a Sherwin Williams P60G2 coating or some other primer is used.
The thought of rubber aircraft fuel bladders crossed my mind.
Absolutely agree with everything. You definitely want to have a couple of ribs in the center to stop the slosh, because with high seas pushing the boat around, that fuel can slam back and forth like a hammer, and depending on if you have an electric pump sticking down into the tank like a vehicle, that fuel sloshing around can break the pump, etc.. You can have holes all in your ribs to reduce weight. The oscillation of the fuel can also resonate and tip the boat more than you want it to possibly; (well, especially on much larger tanks- it's more essential on cruise ships and carriers, etc.). You can definitely weld on diesel tanks, (don't ever try that with gasoline though)...
You can also use "pourable polymer" -- I thought that they could maybe use a pourable polymer in the plastic tanks and it would likely work well. But given how large they are, (and it didn't seem like those plastic tanks had ribs in them) -- I'm not sure if they would have held up to a full tank of diesel anyway, without the mounts breaking. I fully agree with you: Go with aluminum and paint it. With the interior, you could always empty them later and do the "pourable polymer" if needed; and if you're really worried about the bottom rotting out, you could always put in a false bottom in the tank so if it ever does corrode a hole into it, you'll still have a second outer bottom to give it a second lifespan. For me personally, I think I'd rather have 4 or even 6 smaller tanks-- so that if it does have a leak eventually, you can isolate that tank and reduce your losses, reduce the mess and not find yourself stranded because one little leak made you lose all your diesel fuel; to have some multiple redundancy built in I guess.. Sure it adds more fittings and more places to leak, but I think it's a better trade off than putting all your fuel in two large baskets; but that's just me.
Hi Leo
I am a retired marine engineer and classic boat restorer
Over 50 years experience I have found steel tanks to be the recommended choice in most applications and have used steel for septic tanks and fuel tanks the only time I have recommended plastic tanks is when petrol is being used because the water content causes rust
Aluminium is fine but can suffer from electrolysis
Stainless too can be preferred but can suffer long term with leaky seams when petrol is the fuel but have not had any problems when diesel is being used
Now I don't know whether you have considered having a separate main fuel tank lower in the hull and an electric lift pump + a manual lift pump for emergency transfer then having a second tank to provide say 24 hours cruising higher in the boat
Also such a system with a round baffled tank laid fore and aft would lower the potential of an unstable centre of gravity
also diesel tanks will need cleaning periodically and therefore an access plate wold be advisable
hope this helps
I'm impressed with your excellent project management and enjoy the videos immensely
best regards
James Rawson
“Great on hemorrhoids” 😂 let’s keep Richard building beautiful boats so he doesn’t have to get into the healthcare space
The tool.for hemorrhoids is clearly a pile driver, not used so .much on a boat though.
and that grin , plus the look in his eyes. Definitely do not let him near patients! haha
Nice guy for sure, but it bothers me every time I see him working without eye or dust protection. Luck and hubris are not adequate.
You gotta lean into it..
or sit on it apparently
🤣🤣
Hi Leo
This episod was very interesting. I have been working with leak testing during my whole active working life. Especially leak testing of fueltanks within the automotive industry.
Traditionally there have been steel tanks for petrol and diesel. Later came the plastic fuel tanks who where leighter an more durable. These tanks where originally made of plypropelene. The manufacturing process where blow moulding( high volume manufacturing). One of the problems with plastic fuel tanks is the high diffusion rate through the material. There are today some other plastic versions of fuel tanks but they are very expensive. For example co extruded tanks with seven differen layers of different plastic material. Among other a nylon material in the center layer who have a relatively low diffusion rate.
I am glad you are locking for other material than the plastic alternative because the tanks would add some diesel smell into the boat.
Today with the strong demands of hydro corbon escape from the car, fuel tank, the best material is stainless steel or other steel material with a zink coating.
US fuel tanks for the green states ( california among other) havet theese steel materials in the automotive industy.
Aluminum is a light material but it is difficult to make a leak proof weld.
I would recommend stainless steel.
Regarding leak rates on a diesel fueltank. Even very smal leaks will bring a leak who you do not see but it will come out in gas form.
The pressure test is really a very rough test, mening it will detect very large leaks and not the small oance you need to find. The soap method is really effective so stick to that. A pressure of 0,025 to 0,05 athmosphere overpressure is enough. Using air or nitrogen is just fine.
There are other detection methods but expensive.
Please contact me if you have any questions. There are so mutch more to say on this subject.
Thank you for sharing your nice job on Tally ho😀
I think because of the sea water stainless steel wouldn't be an option, you would need to go to duplex but the price for these would make them not practical unless a youtuber could make them.
I agree stainless is the go for tanks but Ali does just as good a job, never had a problem welding Ali tanks even repairs with diesel still in the tank. Not so keen welding petrol tanks though for obvious reasons.
@@edderube1247 welding duplex will be more time consuming. I would say that Tally Ho project is time consuming too. So I would go with duplex -) One might re-design the tanks in the way were the welding seams go. I don't like the way these plastic tanks were welded together.
@@260160nl You could press brake the side and just weld on the ends and fittings.
I seriously don't get it.. Is there no pressure testing of these tanks at all? Or quality check their products? Disgusting work done on those.
Hi Leo and crew,
We have a 30 ft 1975 cruiser on the Norfolk Broads in the UK, a far cry from the beautiful Tally Ho !
We have just had to replace our mild steel Diesel tank as it sprang a leak after 47 years in service, rusted through a seam!!!
We have gone for Stainless Steel as a replacement, our tank is similar (but obviously smaller) in design to Tally Ho’s tanks in that they are contoured to the shape of her hull.
Good luck with the rest of the project, I do most of the work on our boat ‘ Luna Aurora’ so I can to an to an extent appreciate the frustrations you have when things don’t go to plan. And I pick up loads of tips and ideas from you guys.
Keep rolling boys and girls, she’s looking good so far.
Thanks Graham
The way you dealt with the manufacturers of the fuel tanks was amazing. You role modelled the most superb civilised reaction to really disappointing product. Wow.
How the tanks got out of the shop without testing is a mystery to me, and I'm sure everyone watching this.
Agree! I would be ripping them a new one.
Agree and in aviation we.call it being Professional . The problem.with losing your rag is both side are loosers and you destroy the relationship, it doesn't really fix anything.
First class diplomat he is
I'd imagine the conversation regarding a refund for the poorly made tanks involved the threat of being named in the video, even if only implied.
Patrick always makes me smile! Such good dude!
He's always hiding a laugh :-)
He has learned a lot and is now able to produce intricate pieces for the boat. Nice to see his progress! 🙂
All airplanes have drainpoints in their tanks to avoid bacterial growth that will waste all the kerosine and fuelfilters quit rapidly. Diesel is not that much different from kerosine. A minimum amount of water in your tanks ( for example condensation) will sink to the lowest point , all what is needed for bacteria to multiply. For bacteria a pool of water is like an ocean for a person. Great job you are doing and take care.
The only positive I can think of on your tanks is that at least you know that your drawings/patterns are good to go, and fit, and at least you discovered the problem before you installed them. Great video Leo - Thank you for bringing us along.
And one again, way to handle tough situations with respect, poise and confidence!
Yep, not everyone would even have pressure tested them. The leaks would have been a real problem after all the panels were in place.
Tip for using a holesaw in hardwood: drill a hole inside the perimeter that touches the outside edge of the hole. The saw dust will drop through the hole instead of being ground continually.
Plus, use compressed air to keep the cutter cool an blow the dust away. Works for me every time.
wow nice tip deep in the cpmments.
Not just wood. For metals, touch the saw to the work to mark a ring and then drill a slightly smaller ring of holes intersecting the kerf space, spaced maybe 30 or 40 mm apart. This will prevent swarf jamming the gullets, which is what heats the teeth (even with flood coolant because it can't get in). When run slowy enough in a mill or industrial strength drill press, this method can be used in mild steel up to 80 dia x 100 thick provided the saw is sharp
I am a retired diesel technician. I worked as a planner/estimator in the Philadelphia Naval Repair Facility Philadelphia Naval Shipyard in the 80's. PLANNER/ ESTIMATOR OF DIESEL ENGINES. The diesel tanks must be constructed as to repair them as easily as possible. One body construction is not preferable. Two bodies, one molded inner body seamless from a mold. The outer shell can be constructed by bolting it together. The molded body would be the inner. By doing this style you can have a drain plug on the outer body (prefer aluminium - weight - consious) this method of construction is more intensive. It solves to problems - 1. Better security for diesel leakage and 2. A second emergency tank if inner tank fails while underway. It would be easier to replace a molded inner tank instead of labor intensive new tech tank where there a seal seam lrakages as had happened in the tanks recieved. That is my suggestion. Your tanks are not as large as large ship tanks the process I described would be cost effective in repair.
In our boats, fleet of over 40, the larger of them, around 17 or so, all had bladders installed through the inspection hatch. The oldest, a 27 rib ex navy training vessle from the 30s or early 40s, is still running with her tanks that I helped install in the 80s.
Yep, why not keep those tanks and ask the manufacturer to provide suitable bladders that can be introduced via the existing or new access hatches - I presume there are no baffles in them?
@@Kathikas1 There are baffles. 24:12
Patrick using words like "athwartships" shows us just how far he has come :-)
Fuel Tanks: I work with large boats that deal with aluminum tanks for diesel storage. They are well manufactured and they are reliable. If you do the proper maintenance they'll last a long time. There's no reason to go crazy with different metal tanks. I think you can get lost doing the research. If water is a concern and boat building allows, you could add two fittings at the lowest point of the tanks, run to the center line of the boat with the sight glass and a petcock. You can drain out any residual water in the bottom of the tanks. Fuel water separators on pickup tubes on most diesel tanks are about an inch to inch and a half off the bottom of the tank and will only grab the small amount of water that is there.
Love the videos, Love what you're doing with the boat. Looks beautiful. You have a wonderful group of people! Keep it up.
I would vote to go with good old mild steel. Coat it on the outside. The billions of automotive tanks in the world will agree with you, it is cheap but also has very reasonable performance. It can also be repaired by relatively low skilled labor.
Good job guys! Great progress!
Greetings again Leo, if you utilise polypropylene and travel to the African shores you will find most diesel is manufactured with a high sulphur content and ethanol which unfortunately makes polypropylene very very brittle. Please consider another material. Thank you don’t want to alarm you. Lloyd from African shores.
Interesting to know, thanks!
That Purple Heart is such a beautiful piece of wood! Way to go Patrick!
You handled the tank debacle with class. I hate you have to hurry up and wait again. I love this channel because of the workmanship... For one thing. Thank you for the close views and descriptions. You have quite a talented crew. I could watch a two hour video of you all working. Take care and thank you for another excellent episode. Good luck with the tanks. ⛵❤️
that mast step is finer then many high end pieces of furniture I have see. very nice job sir, be proud!
It seemed a shame to paint it.
The hole saw cut is wider than the slot on the aft end of the step. That minute detail would drive me nuts. Would have been an easy fix.
Hello to all. I'm in the process of renovating a 1934 Saunders Roe gentlemens launch. We have recently reinstalled the original copper tanks. We couldn't fault them so....if it ain't broken....
Love the project. Ours is teak on rock elm which is why I started studying your build. Loads of ideas. Sublime attention to detail. Keep it up,
Cheers
Paul
From Yorkshire
I think you handled and dealt with the tank issues honorably and very professionally. A real credit to you, lot can be learned from your outlook in life in general. A pleasure to watch your great videos as always. Cheers 👍
How could those tanks possibly get out the door of the factory? A complete lack of both workmanship and quality control.
ATL marine fuel locker
@@tavpierce1880 What about keeping the plastic tanks and putting fuel bladders inside them?
If the bladder ever goes bad, it is much easier to replace too.
@@dane5412 What about a complete refund and build in traditional materials
I think you give then too much credit for having a factory. This looks like it was done in the garage.
We had exactly the same discussion here. This incident was an indictment of that company. The tank shouldn't have gotten out the door without thorough testing and this tank suggests major problems with their manufacturing processes. Their response suggests that they have a company culture of test and repair. That is a potentially disastrous approach. Every time the product is sent back for repair additional manufacturing costs are incurred and a quality product is almost impossible with this approach because products that just barely pass the tests will be sent out to fail in the field.
Leo was not without blame in this situation. From my perspective he took a risk on a technology that was not worth the risk given the long term cruising purposes he has in mind for the boat and he failed badly on vetting this company. Although my words might seem harsh on this I am a big fan of Leo and this channel. To have gotten this far with only a couple of failures like this, is very good IMO (I'm counting the keel fun as the other failure).
My aluminum tank says it was pressure tested at 3 PSI when it was manufactured/installed. I fabricated and installed some inspection hatches and matching backing rings when I had to clean it out, because the old inspection ports were only big enough for my wrist. When I was done I pressure tested it on my bench at 3 PSI and the aluminum tank bulged slightly, so the bulge on the plastic tanks is not surprising. Unfortunate that yours leaked.
My aluminum tank is 40+ years old and it has held up great despite its battle with diesel bug and water.
Stainless tank 44 years old in my sailboat diesel of various fill level and purity still good I recently installed an inspection hatch and inside was fine apart from the sludge
I really enjoy that you take the time to explain all of the pros and cons of your decisions.
Hi Leo,
Go with mild steel tanks.4mm plate. Hot zinc the the exterior of the tanks once fabricated and then epoxy paint with a polyurethane finish coat. Important to include a spring loaded draw off cock (table "E" flange) at the lowest level to check for water/impurities - most don't do this in any tank, its "ship stuff". Since water sits in the bottom of the tank you can remove it, best checked every couple of weeks. Since it is not an integral tank as in a steel vessel you will not have a problem with condensation.
I looked at a wooden fishing vessel we built 45 years ago, with tanks just like yours and was shocked at how well the port and starboard tanks looked - perfect condition! A fishing vessel has a lot more fuel turnover than you ever will.
Don't worry about the extra weight over aluminium. While it might be three times, your vessel is heavy displacement anyway. The difference overall will be insignificant. Displacement equals comfort!
Right, the weight is about the weight of a heavier crew member and certainly less than the weight of 2 crew. It is also down lower in the boat not on the deck.
Even with Leos calm and cool demeanor I bet there was a moment when that wasn't so and I wouldn't blame him. Such a shame that such beautiful craftsmanship has to be delayed by such ineptitude
He was a real gentleman about it, but I could definitely hear a tremble in his voice that bespoke real disappointment and some righteous anger. I'm glad that the company at least promised a refund and hope it really comes. Quality problems like this don't fit with a prosperous business.
In process industry, we first fill the tanks with water and then pressurize with N2. The thought is that there is a lot less energy stored in the tank and things can’t go flying if you have a rupture.
It's the same way we pressure test pipe systems. If you fill them with air across an entire system, bad things happen if you have a blow out. It becomes a catastrophic failure. Doing a hydro test with N2 really minimizes the risk during a failure as the hydraulic pressure can immediately dissipate without making it a massive blow out.
@@WS102 its only 200mbar / 3psi not much risk there for a pressure test with gases
@@1994kage67 I would not like to stand near that if it decided to blow, even with only 3psi.
If you multiply the volume by the pressure, you get a significant amount of stored energy. More than enough to physically throw someone several meters.
@@WS102 It is not "immediate dissipation" that makes hydro tests safer. It is that fluids are a lot less compressible than gasses, and thus a LOT less energy is required to bring the same volume of fluid to a certain pressure than a gas. And so there is a lot less energy to release in case of a failure.
Energy = force times distance; the forces (=pressures) are the same but with a fluid the distance is a LOT smaller -- ergo the energy is a LOT smaller. Less energy stored in the container means less energy can be imparted to the bits that fly off in case of a rupture.
@@TheEvertw Exactly, the resultant low volume of compressed air is insignificant compared to a fully compressed air only test. The level of kinetic energy generated is minor compared to charging an entire system with compressed air which has the potential to create major damage should the pipe or any fittings fail. Hydraulics make it possible to do it safely.
Emotional intelligence shows through again with the diesel tank issues experienced. Like others have said, well handled, Leo. You've chosen materials throughout the build for longevity of the boat. In my humble opinion for a sailing/working vessel, don't sacrifice proven longevity for the weight savings of a material that might have a short lifespan & amounts to 1.5 deckhands. Keep up the great build, craftsmanship, and content!
Decisions, decisions, decisions! But you're on top of it and are being careful with your engineering. Returning the plastic tanks is essential for you, and it's actually useful feedback for the manufacturer. Next time they will be more careful and will build a better and thoroughly tested tank.
A fuel tank is not simply a bucket to store fuel. It is an integral part of a dynamic system and requires precise engineering and installation. (Check with the folks at Ford concerning their Pinto experience!)
I'm going to guess that you will go with the time tested, steel tank, well-baffled, ventilated and with adequate and accessible drain clocks. No matter the material, or construction, keeping water out of your tanks and fuel lines is essential to basic operation, longevity and safety.
And, while we are dealing with combustibles issues, I hope you will be equally careful about fire suppression in and around your fuel and engine compartments. The motor coach builders have some very nice systems in some of their vehicles, from which you could choose, or you can design your own. Either way will be costly, but fires happen. When they do, they need to be immediately put out. A motorcoach can be fully involved by fire within 2 minutes. Those folks have largely learned their lesson about putting a multi-million dollar machine at risk, due to a small fuel leak, overheated engine, or collision. You might check with you insurance underwriter, as well, to see what they may require, or recommend.
Patrick's skill progression is just amazing.
As well has his speaking of what he is doing. He at first was an immature youngster having fun and learning. Now, still having fun and learning, just much more mature. Nice watching him grow up.
Total respect for Patrick, this project has benefitted from his skills massively.
Me: I wonder what those horizontal bolts are for?
Leo: You may be wondering what those horizontal bolts are for...
These are to reenforce the wood structure, to avoid that it could crack in a natural wood defect that you don't see.
Just like in a building outside walls, the old ones.
As you can see, there are more skilled person's to explain to you more cientifically the purpose of putting those axes and bolts.
The bolts are actually to support the thinner cross grain sections that are the weakest part of the wood grain. Stress along the grain lines in the wood block are the strongest, (like the tree standing up) but force at 90 deg. to the grain lines will separate with less force. Hence the use of the bronze bolts is to introduce 90 deg reinforcement and added stress capability to those weaker areas.
I think your wit went unnoticed. I was on the same page and timing as you were.
@@davidrenaud736 Thanks David. I was leaning towards "Nautical Flux Capacitor"
I guessed right! , learning so much from these wonderful videos.
Nick is a pretty sharp cookie - his workmanshiop is consistent with the other crew - EXCELLENT!
The way he's sporting his locks makes the girls run crazy. Don't let them distract you from your important work, Nick✌️😁
I'm a fair Carpenter but compared to your crew I'm a Midwestern wood butcher
Patrick always had skills. His transformation into shipwright is a testament to what happens when talented people are lucky enough to have experienced mentors who share, coach, and teach them the art of craftsmen ship.
Now that's a fact!!! We could all do similar things, but having a good guide is key.. n more importantly, is willing to admit u don't know it all along the way.. it's wonderful to pass on the knowledge obtained, but it's also nice to have a person to draw from their experiences......
Oh, my goodness... you are so dead on with That Statement - Thanx
Hi Leo, I have a few thoughts on the diesel tank problem, on large steel ships what usually writes the ship off to be an un-economical repair is the tank tops rusting out. The tops of the tank are vulnerable as condensation gathers there due to the air gap that is at atmospheric the bigger the gap the more condensation especially as Tally Ho's tanks are in a relatively warm place. I will cite HMS Britania, she had such a problem and it was more than financial. Anyhow it brings me around to the absolute bulletproof blow-molded ABS plastic used in the automotive trade by most volume manufacturers, it has got to be about the perfect material for the job as there are no welds involved, you have the molds already formed, but finding someone to blow them will be difficult, that's my thought, hope it helps. Cheers from the UK!
Is it possible to get custom shapes? Because he might end up having to spend too much on tooling
It is possible to "positive"-form those by blowing ABD into a form, or negative-forming by pulling the ABS into a form with vacuum. Problem here would be the "one-off" character of these tanks. The cost of a proper form to blow/vacuum the tank to does give reasonable results with high numbers of parts only.
Love Richard’s safety glasses.
Perfect for those surprise OSHA inspections 😀
Right you are, best gogles what can be provide😎.
I like how a man with his experience simply 'flips the bird' to safety stuff he reckons is over the top. Richard rocks.
I'm assuming maritime tanks must have a drain valve for the water accumulation like aircraft tanks? Take a look at the aluminum fuel tank on a Pitts Special, it's mounted to the fuse with straps, somewhat isolating it. Some of the examples on experimental amateur built Pitts S-1's are very crudely welded, yet despite the twisting of the fuselage during aerobatics, they hold up astonishingly well and also repair well
Really glad you detected the leaks prior to installation and filling , imagine how much of a mess that could have created . Leo , your attention to detail and quality control is very impressive . I performed Construction QC on large projects , and was amazed how often new equipment or materials were defective . Great woodworking & music , great video .
A cursory glance over the seams showed their low quality, I guess that is why they did those pressure tests.
This is one of those great times to be documenting everything publicly and on camera!
Also, that "great on hemorrhoids" joke absolutely killed me. Great work as always, guys. I love this channel.
💙 watching Patrick's skillset improve over time !
I didn't know RUclips watched RUclips
Huh. It's not a fake. That's.......unexpected.
Bring back the dislikes
Happy to see, but not surprised, that the folks at Google/RUclips recognize one of the top channels. And I agree, bring back the dislike button with counter. It’s helpful.
Bring back the dislike button lol! :D :D :D
Leo, I’ve seen a few comments regarding aircraft bladder type tanks. It is definitely worth looking at how they would handle marine conditions. Probably comparable in weight to aluminium, but more durable. Back when I worked in motorsport we turned to the aviation industry for quite a few techniques, tools, materials and suppliers.
I'm assuming that Leo knows about FuelSafe in Oregon but perhaps not. Or he checked with them and the lead time and/or price was prohibitive.
Atl is another manufacturer
Retired A&P mechanic. Bladder type cells work good. And are tested on the workbench before installation into the cavity. They have aluminum flanges for rigid or flexible plumping. And most are laced into the cavity, installed though a oval manhole. Seldom have problems, if correctly installed. Can also removed and patched.
@@bobgregg7469 what are lifetimes like on them these days?
I used to work on some aircraft with bladder tanks. They all leak. Sealed aluminum wings perform much better.
I need episodes every week, I can't live like this anymore😂
Wow lots of comments! My vote is for steel tanks. I would use cold rolled sheet as it will accept the epoxy much better without sandblasting. Hot rolled sheet really should have the scale removed by blasting before coating for maximum adhesion. Round aluminum tanks are really strong and durable but square or odd shaped aluminum tanks seem to fail way more often.
You are really studious on these things so no matter what you choose I am sure it will be what is best for the boat long term.
The weight of the diesel sloshing in a plastic tank would really bother me. It would need to be heavily baffled to prevent rupture in bad weather.
Leo, you show what a true gentleman you are by how you handled the issues with the tanks. Many, many of us, would have been angry and thrown the manufacturer under the bus but despite a huge setback you kept your cool and forged forward. I could see how these skills would be of great value while captaining the boat under trying circumstances. My admiration gains through every episode. Cheers.
Hi Leo
A masterful series. And I learned a lot from your journey..
The automotive industry uses aluminium which is anodised. Under-saddle motorcycle components are exposed to severe corrosion due to salted road conditions. Anodised aluminium is less likely to corrode than standard aluminium because it has a thicker oxide layer. Finally, anodised aluminium offers greater adhesion for adhesives and primers. This is because the oxide surface of anodised aluminium has deeper pores than that of standard aluminium. The pores are essentially holes in which adhesive, primers or liquids will flow when applied to the surface. As the anodized aluminium soaks up the liquids, it allows for greater adhesion.
Fascinating to see you use tools that I didn't know existed.
For diesel tanks on offshore vessels, in my opinion, carbon steel. The external corrosion can be managed. One important item not talked about is the tank fittings. As you witnessed the concept of tapping NPT thread into any parent material will often go badly. Wall is too thin typically and requires reinforcement pad that will have a seam/flaw between shell and re-pad joint. All tank penetrations should use welded threaded fitting, ASTM flat thredolet is recommended to achieve proper thread engagement and reinforcement of tank shell for mechanical strength. For tank bottom fittings use a NPT size that allows sch 80 or sch 160 pipe nipples before your first shut off valve with sufficient ID for required fuel flow. Standard wall pipe nipples are too thin and weak at the threads for any accidental mechanical loads or an over zealous pipe fitter. Of course minimum guidance from ABYC H33: Diesel fuel systems. After all these years I don't mind diesel odor but many do and diesel has habit of weeping from poorly executed threads and fittings.
I made a plywood tank because I had run short on cash but I coated the inside with Epoxy and reinforced the seams and baffles with glass tape and then did the same on the outside. I have never had a drip of a leak and 42 years on there has been quite a lot of diesel pass through it. I have a drain cock at the bottom which I drain every few years. I wonder how much better a job one would do now with thinner ply impregnated with resin and using kevlar instead of glass. Neither expensive nor difficult and all so easy to fabricate to fit!
Think about glass fiber reinforced epoxy diesel tanks (or carbon fiber), you may be able to use the old plastic tanks as a mold (inside or out). You do have baffles designed in for added strength and anti-slosh, don't you? Also design in large access holes for inspection, maintenance and repair.
Hey Rich, i believe your fiberglass idea wont work at all, the tanks have access holes already so you dont need to tell and there are other ways to stop sloshing in a tank than baffles.
@@mm-hl7gh i love how nice and polite most of the audience in this channel is.
this is constructive and it inspires me.
my own me would have said something more like
"hey rich, you sound a bit arrogant there, barking your bad ideas down from up on your high horse"
but clearing it up like you did is just nicer.
cheers!
These tanks fit well. Use them to make molds and then build fiberglass tanks. Well build fiberglass tanks will last a very long time. Keep the molds and spares can be made in the distant future.
That would be some excellent content too.
I see you finally used the Odie's oil we sent you!!!!
With two tanks, particularly if you don’t see yourself running through a lot of diesel, you might install a fuel polishing system. You could then polish (clean) the fuel from one tank to the other and then back, removing sediment and moisture, thus keeping the fuel clean and reducing your concern about aluminum tanks.
Or use a third, small, "day tank" like a lot of ships do that pre-filter or warm the fuel to be used.
@@danweyant707 There recently was an interesting video from Alluring Arctic Sailing about exactly this! ruclips.net/video/9WblFBR-gOE/видео.html
Having a small buffer tank below that main ones, and the drain of these two at the lowest corner, so the water will always be at the small (probably plastic made) tank
@@mathijs58 100% correct, that system looks good.
@@mathijs58 100% correct, that system looks good.
Who knew Richard had such a terrific sense of humor. Hemorrhoids, what a hoot.
And he was so damn proud of himself after that 😆
Old boy dropping a nuke 😅
😆Watch some idiot try that out and them try to sue them.🤣
Leo a Question...??? Have you investigated fuel tanks similar to aircraft? They have an aluminum structure of course but have a Goodyear Bladder insert, the bladders are custom built to fit several angles and have transfer tubes installed so you can remove the tanks due to age or leakage. We used them in many aircraft for the Military and they can be made to be self sealing as well, in case a bullet should penetrate the structure. The weight would be similar to you plastic tanks but will not leak like those did.....
I really love the way you dealt with the tank issue, and it is so different from what cable tv shows would have done and why I love watching content like this. Instead of milking the drama for all you could, you made the most of it and I actually learned a lot from the failure of those tanks and your exploration of other options that I wouldn’t have if everything worked well. And to me this is an example of how people should strive to act in frustrating moments. Despite obvious extreme frustration you didn’t dwell on it. I of course don’t know what happened off camera, and maybe there was lots of yelling and cursing, which is reasonable, but this incident is why I love this channel. (Also, hemorrhoid joke caught me off guard and was hilarious)
I don't know tanks in boats but I do suspect there's a tank manufacturer out there who'd be glad to fast track your project in order to be the subject of one of your excellent videos. It might even be a welded plastic guy who wants to do it right. Good things happen to good people. Every crisis has turned into an opportunity for you thus far. Your eager fans eagerly await the next episode!
for real dude
I completely agree! There are times when drawing more people into the crisis, the better the outcome.
Many hands..... light work.... Stay connected my friends
Hey Leo - As always, excellent video and great project. With 35yrs. in the Marine Industry, and a former Boatyard Manager I have had many years of exposure to a variety of diesel fuel tanks...and without a doubt mild steel tanks with a proper epoxy coated exterior is the best option. As you said, most commercial boats use steel and there are tanks 80yrs. in service without problems. And if your calculations say that you only have a 200# difference between steel and aluminum ... then send that "fat guy" in the cockpit up to the foredeck!! 🤣🤣🤣
Hi Leo great job so far ...... I have worked on and built working boats for over 45 years, building altering and as a professional fisherman on both steel and aluminum with both types of tanks.
Welded aluminum tanks are a bit weak in the weld department especially if 1/2 a tank of fuel can slop around in rough seas and are next to impossible to repair if a leak does appear. The one I have had a bit to do with were marine grade aluminum and usually made as a part of the hull.
Besides the weight of steel tanks you have to be a bit careful if they are kept partially empty for extended periods of time as they can rust internally when the fuel coating dries out ( does take time thou and good filters can usually take care of that).
What ever you decide to use make sure they are tested before any coating are put over them, in the case of steel preferably after sand blasting and before painting.
Ps I have had to repair both steel and aluminum, the steel one had had diesel in it for years and wasn't a problem to weld where as the aluminum was new and had water put into it for testing and it took days with die grinders and welding to fix it.
In Australia, it’s fairly common in timber boats to have 316 grade stainless tanks. Id highly recommend them! We have almost a small sump on them so any water sediment can easily be drained off.
I agree, A4/316 is really really corrosion resistant. No experience of it's compatibility with diesel though. Really good diving equipment is made of it. Pricey though.
I've owned a 55' steel yacht for 16 years (in Australia) and it has 1400 litres of diesel spread across 5 ss tanks. The boat is 40 years old and the tanks are still holding together ... that said, the seam in one tank began to leak 9 years ago, which required me to cut the top of it open (after dismantling the starboard saloon furniture) in order to fit another slightly smaller ss tank inside it. So on reflection, I feel your dilemma, but would probably still go with ss again.
Such a shame that someone would send something out of their shop in this condition. Whomever was responsible for quality control in this facility should be held accountable for this disaster.
Leo, as a former long haul trucker, that spent a lot of time in and out of coastal ports, I would recommend the steel tanks. Yeah, there is the weight consideration, but you can balance out with ballast in the bow if need be, and it shouldn't raise the LWL on the hull by maybe an inch, two at best. The trick for keeping condensation rot at a minimum, even with a water drain in the bottom of the tanks, is to put a blown in liner inside the tanks when manufactured, before they're ever filled with any testing gasses or fuel/diesel. And, of course, as you've said, a sturdy epoxy paint or outer powder coating finish as well. The inner coating should be easy enough with your inspection ports as a lot of diesel truck tanks and motorcycle tanks inner liners are blown in through the filled neck.
Just something to think about.
Good luck.
Oh, another consideration. Should anything get tossed about in rough seas, steel tanks would take a hit from a random object better than aluminum ones would. 🤔
If you're gonna blow in a liner, why not aluminum? Weight on a floating vehicle is a bit more sensitive than weight on a truck, and impact resistance should be handled by where they're installed, whereas most trucks' tanks are right out there ready to catch gravel.
The added weight is more complicated than just balancing it out with more weight at the other end of the boat. There is moment of inertia to think of as well... Take two boats of the same overall weight; one that has more of its weight concentrated amidships will ride better in a sea than one which is heavier at the bow and stern, even if the overall center of mass is the same in both boats.
I liked that idea of the blow in liner. Could you blow this in the plastic tanks you have?
@@danjelowitsch If the tanks already have cracks then any flexing over time will propagate the cracks. Like when your car window gets a tiny crack and then it spreads.
Leo I have designed equipment for the offshore oil industry for 30+ years and I can see that you have done your research. I would offer another option for the stainless alloy tank. In the last 15 years when corrosion and stress corrosion cracking is a concern the most logical materials are duplex or super duplex stainless steel. Besides the extreme corrosion resistance it is also more than twice as strong as regular stainless steel so the tank could be fabricated out of thinner material thus saving weight. Although many people are not familiar with this material it is quite readily available. I hope this helps some.
Hi Leo, just adding to the discussion on the best material for fuel tank. A 43' plywood boat was built over 40yrs ago in Fiji with a mild steel fuel tanks install. It lasted only 5yrs before it was replaced with marine grade plywood fuel tanks heavily coated with epiglass everdure wood sealer. The plywood fuel tanks are still in use today, 35yrs later.
The rain has finally come, the wildfire smoke is gone and a new Sampson Boat Co. video... happy birthday to me :)
Edit: I vote aluminum since you're weight sensitive and I know you'll maintain it properly.
Right?
And happy birthday!
Happy birthday!
Happy birthday, 2024 T3 Alclad aluminum will last for decades. All in
Hello Leo
Every second Sunday morning a great pleasure to watch your videos with a good cup of coffee- all these years long!
A comment to your tank-theme: it seems your plastictanks have no middleparts or sheets to withdraw the movement of the Diesel. If the tank is half filled and you are in heavy weather there is an extrem force running against the front and rear wall- plastic and even polypropylene will not resist very long -even your low pressure test shows a very high deformation, imagine this in a 5 seconds rhythm for hours and days!
In my experience a Steeltank is the favorite, 5mm thickness, at least one sheet with holes, traditional or wig/tig-welded (no inert gas welding) from inside and outside and a good epoxycover- and don’t forget the wateroutlet at the bottom! Good luck and always a hand´s breadth underneath!
Norbert from Germany
As soon as I heard you say that you bought welded plastic tanks, I was like, “NOOOOOOO!” We (water/wastewater treatment) have several that we use for NaOCL, NaOH, NaMnO4 (and others) and have had nothing but leaks from day one. The company is two states away, so we have to deal with the containment until they come out to repair them (which, has never went well - worse leaking). We do have a small, 100 gallon stainless steel tank that we use to refill emergency generators with, and has lasted for going on two decades now without any issues.
No quality control from the manufacturer? Seems messed up to ship a faulty product.
A faulty product definitely can be described as messed up, yeah
A tank like that is required to pass a pressure test post production and before delivery. I do a lot of tank testing in my field working on luxury yachts. The fact that those tanks were delivered in such condition is scarry.
@@AllFlimmits 2 thoughts:
1. Maybe the welds were somewhat faulty but passed inspection at the manufacturer and later on split open at the welds during shipping due to vibrations.
2. Maybe QC was only done with water, and no additional pressure, just like its use case would be, so none of the welds split open compared with the high amounts of pressure Leo put on there.
But that begs the question if they would have lasted over the years.
@@berinslaptop What material would you recommend?
Fibreglass hand layup. Used them in commercial fishing for over 40 years never a problem
Hi Leo, I'm half into a bottle wine in already, but when I saw these were welded plastic tanks my hair stood on end. I have been in aerospace engineering for 40+ years and would not trust those for fatigue when the fuel was sloshing around, so very well done to you team for the pressure test and I think you have had a near miss. That is no reflection on the manufacturer, I'm sure they made their best endeavour and plastic when moulded can be wonderful for this task. Your challenge is achieving maximum capacity for the available space and reliability. As stated, I would not go for aluminium either. For my input, I would investigate steel tanks made in Cor-Ten steel, as I'm sure you are aware steel yachts are made from it (I have zero experience).
Put plenty of fully welded baffles in place too.
he needs to implement anti sloshing fins inside the tanks for more stability just like they do in airplanes ,he already has more range than he needs and i think its a fair trade !! stability for capacity
@@fouzaialaa7962 Agree with the need for baffles to reduce sloshing, I was surprised thet they were not included in the design.
I have an S&S yawl that needed new diesel tanks and ended up using 3/16" or even 1/4" aluminum, it's been 16 years now and I forget which. The tanks have baffles. On the exterior, I had them Rino Coated (like they use on truck beds) and mounted on sleepers. The exterior of the tanks has held up well and look like the day I put them in. I worked on building the Matthew Turner in Sausalito, CA for a few years and enjoy your videos. Great Job!
To the manufacturer of the plastic tanks:
You did understand that Leo has a famous RUclips channel. Your workmanship was gonna be front and center and yet you still sent them looking like this. I thank you for having intestinal fortitude to make it right and pay Leo back and cover shipping. You should take this as a learning experience and treat the construction of you products as if it is gonna be seen by thousands of people.
yes, it's going to be seen by nearly a million people. To send tanks that shoddy out the door is inexcusable.
At least test the tanks before shipping them. SMH
Hey when you get metal tanks, make sure they weld a plate and some eye hooks up there so you can move it around! Have another set of eye hooks screwed to the bottom of the deck so that you can use a rope to lift the tank into place using the sets if eye hooks . I.e. pull the tank up into pace by bringing the sets of eye hooks together.
When I saw the plastic diesel tanks they looked sub standard and I thought they would need to be supported on all sides to stop the sides bowing. I’d go for 5083 marine grade aluminium tanks. The thickness of the aluminium will be the key to longevity. I’d put the inspection lids/holes as high as possible if they can’t be on the top of the tank with near zero pressure from the fuel. I installed a 60 gallon aluminium diesel tank in a 71ft narrowboat here in England in the early 80’s which was expensive at the time but gave me no issues at all and looked pretty neat too. Love your channel and maybe one day you’ll sail into Gloucester docks so we can come and visit. 😎
After careful consideration and long pondering. The answer seems to be fairly simple. One steel tank. One aluminum tank
Mast step piece looked like a lot of planning and work. Nicely done.
Sorry to hear of the wasted time and effort on the tanks. Classy resolution, as expected, by Leo. Good to hear the company will be honest in resolving.
You can make molds for rotomolded tanks. It's quite easy.
The labor and materials is basically the same as making a tank from AL. I have made large molds for a product I manufactured. Wall thickness was 5/16". The mold can also be used for a tank too. Also you can build the tank from alluminum and fill it with plastic and produce an inner liner that isn't removable.
I'm in Vancouver BC and there is a company here that has the ability to produce large parts. If you would like to discuss this option send me a message. I'd like to help with your project and this might be just the opportunity.
It’s a bummer about the tanks, but better to find out now then later, another great episode with Patrick starring and directing .⛵️
Go with aluminum and add water socks to your routine maintenance schedule. In a nut shell they are a sock designed to sit at the bottom of a tank and absorb only water. Also a big aircraft company not far from you have been building fuel tanks for a long time. Maybe you can glean some knowledge from that industry. I have been watching for a long time and look forward to the weekly updates. Tally Ho!
Yeah! Boeing! They know how to build the best fuel tanks.
Good idea. That´s what I would do! Why not name the aircraft company for reference?
" a big aircraft company not far from you" rofl
The following coating spec or some equivalent would pretty much guarantee to nip corrosion in the bud:
1) Clean the tank and treat inside and out with Alodine 600: it's formulated for brush or spray, but because it's an aqueous solution it also works for dipping: the interior could be sprayed generously using a 90 degree spray nozzle on the end of a long tube, and any excess immediately tipped out and brushed on the outside before proceeding to brush fresh solution on the rest of the outside. This solution chemically converts the oxide layer. "...the film formed during the alodine process is not as thick as an anodizing layer. This film is a complex metal-chrome molecule film, and it later forms into a continuous gelatinous coating. It is the continuous gelatinous coating that prevents corrosion from happening by eliminating chemical processes."
2) Alodine does not resist abrasion, so it is used in (for example) the aircraft industry as a preparation for paint.
The best paint works by chromate conversion, like Alodine, but zinc chromate paint is not very healthy (if precautions are inadequate) for those who use it day in day out so it's no longer used in the industry - some who have been around for a while will have seen the characteristic olive green colour before aluminium aero components got finish painted.
The paint is still available, eg : www.aircraftspruce.com/catalog/cspages/ptiprimers.php?clickkey=17411, click on "Zinc Chromate Primer"
3) For ultimate corrosion and abrasion resistance, cover the paint with a proprietary truck bed liner, like Rhino Liner (which I believe is from Seattle), or with coal tar epoxy.
I omitted to say that Alodine would doubtless be sufficient inside the tank, but I suppose a gold-standard solution would prevent the ingestion of water vapour by sealing the tank filler, and using a nitrogen-filled bladder as a volume compensator (eg Pronal EXP inflatable separator) inside the tank, maintained a tad above maximum atmospheric pressure, in lieu of a breather! High spec coastal rescue boats, which are expected to experience inversion during operation, sometimes have something along these lines. Along with gravity operated closures to the air vents feeding the cabin and engine room forced ventilation systems, and similar units on the snorkels for the engine intakes.
Such a system, for a cruising boat, would require refuelling to be done via an intermediate chamber (perhaps a day tank) from which it would be pumped into the storage tanks, to collapse the compensator bladder as well as prevent air entering the tank.