Hi Brian, I've been working in the heavy truck industry for almost 3 decades. We use loctite 5699 to seal rear carriers to the axle housing, the holes are tapped into the axle housing, and the carrier is bolted to the housing, very similar to how you have your tanks set up. The good thing about using this sealant, it can be also added to your threads to help seal around the bolts. We pressure test out axles at 8psi, and this stuff holds every time. It is oil, water, and glycol resistant, and is NSF. We buy the large caulk tubes, and use a caulking gun to apply it, makes things easier. Good luck with whatever you decide. The new boat is looking great!
We installed a small window in the hull just for viewing the prop/rudder area. When kept clear it proved very useful for viewing what had got wrapped around what. If Delos 2 is cruising cold murky kelp and fishing line infested waters with two sets of sterngear to consider you might consider welding in stackpipes that extend higher than the waterline to allow an action cam on a pole to be lowered for examining sterngear and keel without having to first go overboard
Hi, I have a suggestion for your fuel tanks --> Check out how Single Engine or Multiengine trainer aircrafts store fuel in their wings. If I'm not wrong they store fuel in "bladders". Moreover, I notice that when you are trying to seal your fuel tanks you are doing it from the outside. Note that when fumes accumulate in your tanks they will have a propensity to exert outward pressure from within. So note that even in balloon or tubeless car tyres they use a sealant powder to guard against leaking punctures and they use soap and a perfect fit iron gasket seal within the tyre extremities to fit perfectly in the rim. Now you can't use a sealant as it will contaminate the fuel itself. If I were you I would still go in for the "bladder" fuel tank approach. This would drastically reduce the possible number of structural manufacturing defects to 2 - one, the bladder and nozzle seal and two, the nozzle itself. The only other possible operational defect would be one or more punctures. In your current approach, each of the nuts and bolts is a possible defect in addition to the gasket. A gasket is used in the engine manifolds but not the fuel tanks as there you have metal meeting metal which requires a seal which cannot be avoided. But in your fuel tank you can avoid this in the design itself. Even the Refueling heavy aircraft use bladders to store fuel in bulk for their client F-16 or B-2 or Falcon clients. My friend, forgive my bluntness but I think your approach is seriously flawed due to the number of possible defects in your design. Please reduce the number of possible defects in your design.
If Riley had chosen this design and this build method, it is likely that when the collision occurred the other boat would’ve been damaged and this boat would’ve been intact.
Gaining experience is always a long, laborous and expensive adventure. As an aviation mechanic (Electrical-electronic) it would always take me 2 years of a 3-year tour learning the aircraft (ie getting experienced) b4 I could routinely troubleshoot the systems and get it right the first time. It is a glorious feeling to be in that space. Brian, the lessons you are putting on video are invaluable! Thank you and Kazz, you guys are awesome!
I have found in my industrial career that a wider gasket is not as good as a narrow gasket, think of the PSI (pounds per sq inch), more square inches is less PSI while less square inches of gasket equals a higher psi. The Teadit or Gore Tex as we called it should have been perfect fort this application Pat
First Like! Love the Delos crew. I had a similar upbringing as Sierra's, my dad converted an old bus into a mobile home and we spent the first 15 years of my life, I traveled throughout Europe, Africa and the US. Almost completely home schooled. On land vs the sea, but similar traveling experiences. I am so happy to see how Sierra is growing up, she is experiencing wonderful things and will keep these memories with her forever. I love the way Delos 2.0 is coming along, Brian's capacity for engineering and finding creative solutions is so entertaining! I also like how Kazza contributes to the buildout in the living spaces of the ship. I've binge-watched every video Delos has released, simply fascinating in all regards. Go Delos!
Warning!!! Aluminum doe NOT have a fatigue limit like stainless. The Aluminum bolts will stretch and loosen over time!!! I HIGHLY recommend replacing them with stainless bolts...The only issue with your fuel lid was that it needed a stiffener about 1/2" (11mm) x 1(25mm)" wide welded to the top edge where the boats go through... Would have solved all of the issues and I would have use a liquid sealant material. It will also minimize any galvanic corrosion. (just the opinion of an old grouchy engineer)
consider counter sinking the fuel pump mounting surface down lower in the lid to allow for the extra room needed while using the raised flange style on top of the tank.
Consider using two-part aviation fuel tank sealer. I used to repair 3 marine diesel tanks 14 years ago. I used rivits while the sealant was setting. Use for the large panel..
For Your fuel tanks, use barrel nuts and use a sealant such as 8802. That is what we used on aircraft hatches. There should be a sealant that is water safe also. The barrel nuts are usually riveted on. Then use the seals you have for the hatch lid.
Flex, flex, flex! Use screws from the top into closed rivnuts installed in the tank flange. You need twice as many screws as you have now. Use MIL-PRF-81733D (B1/2) to seal the tank and flex and leaks will no longer be an issue.
17:52 Use the same idea here for the tank covers. Cut some slugs out of bar stock drill and tap them, then drill holes in the tank and weld tapped slugs in the tank top and grind flush, and than bolts will be sealed.
I've been through this exact problem with a hydraulic oil tank and trust me you ain't done, yes you might have a seal now with what you've done but it's not reliable and it will leak again. I finally sealed mine by welding 12mm thickening flanges around all the openings, that means welding the inside and outside edges to the tank so there is no path to the bolt holes in the thickening flanges which you should drill and tap before welding them on. Weld up and clean back the existing holes in the tanks first before welding the thickening flanges on so the finished fastening holes are essentially blind tapped holes. Red loctite studs into the flanges don't use bolts. Yes you now have 10mm plate lids, I would have used 12mm. Torque the fastening nuts so clamping pressure is even. Consider making a test rig to check deformation on the 10mm plate lid, just jazz it up with some off cuts and include the rubber gasket material, make it about 4 bolts long at the bolt centers you have chosen for the tanks, torque it up in stages, evenly and measure the deformation with a vernier so you know what the torque limit is without deformation. It is possible you might need to double up on the studs for the fuel tank and of course the flanges would need to have the extra holes drilled and tapped before welding down. A bit of a dribble on a water tank is annoying but a leak on a diesel tank is a pain in the arse, remember diesel is quite capable of finding a hole in a glass bottle with a screw on lid and a drip go's a mile, hydraulic oil is worse it go's about 2 mile.
Brian, great job getting those tanks sealed. As with all projects, sometimes the best thing to do is take a step back, get your mind off of it, and let the solution come to you. Sometimes, the closer you are to something, the less you can see! Loved the aluminum washer idea. I can see how torquing those nylon washers down would cause deformation. And yes, the fiber washers are a great idea. I use them on my boat engine carb (I have an Atomic 4 engine. Great engine, if you stay on top of the fuel system and properly vent engine compartment). Also, good idea switching to the aluminum bolts. I know they're not as strong as stainless but like you said, this isn't a high torque area. You just need something that keeps a stead pressure on the lid and gasket. About the only other solution would have been your idea of building a lip to weld to the tanks and then bolt the tank lids, but you didn't have clearance between them and the floor. About the only idea I had for that was to raise the floor up a few inches, but that would probably mess with something else! Congrats guys and good work!
On our Vans Aircraft aluminum fuel tanks we use proseal a two part mix. Cures in a few days, never hardens - fills in the uneven surface. Might look into it.
The problem is the lidd and the tanktopp, they are only made of thin aluminium plates. They are not stiff enough, they flex when you are tigthening the bolts. And the more you tights, the more they flex. You must make the tanktopp and the hatches stiffer by welding on an additional strip of aluminium. SkipPer
The original design had a much stiffer hatch opening , that got canned to reduce the height. I commented last weeks video they should keep the stiff hatch opening but the flange inside the tank instead of on top, to get the height they want, and that lid needs thicker rim as well.
Hi Brian I worked as an engineer repairing and installing petrol and diesel pumps for many years. We used sheets of Cork to make gaskets. Lay the Cork over the top of your tank and cut your gasket using a small ballpoint hammer, tapping gently around the edges cuts the gasket to perfect size. Good luck.
He's right. Cork is one of the best gasket materials there is. Only way to beat cork is with O-rings set in grooves machined with a ball mill. EPDM is pretty great too though.
Cork was used many year ago ,there must be a better material .Rubber is often to "hard" any type of flexibel material,dieselresistent ,must be usefull.
It will not work as the flange is way to big. The bold-hole start leaking and wil do as the boat is flexing and or temperatures will work the panel. Cork or even paper will work with thick flanges like on pumps . But these panels are suck. Way to large
Exactly, Machinist Engineer here that deals with custom gaskets and seals all the time. You have to understand the fundamentals of what a gasket does, and how it works. It's main job is to take up the inconsistencies and variances in gap in two mating surfaces. You may think you have two flat plates you are working with. They are not flat. In order for the gasket to work you have to achieve 2 things, 1 adequate clamping force, and 2 rigidity of the mating surfaces when those clamping forces are applied. Your problems right now are that 1 you do not have adequate clamping force for the material type and width you are using, in PSI, and 2, you are getting localized deformation at each fastener location as they are spread too far apart. Cork solves this as it is a much more compressible material than nitrile sheet. Secondly, a wider gasket is not necessarily better, Wider gaskets have more surface area, more surface area means greater forces need to be applied overall to achieve adequate deformation psi. This is why o-rings work so well, the clamping force is concentrated in a very small cross section of the gasket material meaning it can easily deform to the contours it needs to seal against.
Consider taking a 2" strip of metal and weld it to the back of the fuel tank lid @ 90 degrees (short it so the lide gasket is not even close). Think baffles, but on the lid. Stiffens the lid by a ton, quiets the tank, adds only a little weight. Keep up all the awesome teamwork, you guys are doing great. Know your/you're love
Hey Captain...25 plus years in the metal trades...you need to stiffen your cover plat for your fuel tanks...or any tanks...aluminum is not stiff, hard, or how ever you wish to describe it a piece of angle around the out side edge...flange up...drill and tap should work fine...ask you ship builder how he sealed his tanks...unless they weren't built in....
One of your viewers mentioned aircraft wings. I was in Naval Aviation flight crew. We had wet wings and constantly had to inspect our fuel cells. We had sealant mixture that was a brown putty . Like a permatex. Natural the wings were aluminum. And if we had a rivet leaking that’s how we would seal it from the inside. Crawl inside and putty around the rivet.
Do your fuel tanks use breathers? For example, in a truck differential, driving through cold water causes the diff and contents to contract and create negative pressure, sucking in water. A diff breather is a tube from the cavity up far above water level, open to the air with a tiny filter on the end, to allow dry pressure equalization. In your case, as you use fuel (or water) you are going to need to let air into the tanks, unless you use a bladder. Your tanks thus need a breather tube up out of the inhabited spaces to somewhere outside well above water level, venting in such a way as to prevent fire or inhalation risk from the fumes.
Hey guys .... those anode recessed boxes are a granite idea for hydrodynamic but in my experience if the stray currents have to take any sort of corner they hit the sharp corners next to the anode... I would suggest rounding the corners where the box meets the hull on the outside and also put a big fillet well on the inside to give it more thickness just in case...because it will become a concentrated area of electrons .... grate build I'm love you channel ...
Have you thought about welding in aluminum female threaded inserts? So that the bolts themselves do not have to be sealed, it would just be the cover and tank then. Just like the original flanged plan.
seems like you're trying to use a mechanical solution to fastening the bolt to the tank. why not weld on the bolts to a flange plate outside of the sealed area.
Exactly what I was thinking. As a mech on H3 and H60 helos, which are essentially the same construction as that aluminum boat, the fuel bladders could be deflated, stuffed into any irregular shaped vessel hold, and filled up with no leaks.
To save weight on the tank lid: you could combine the thinner lid with angle 6061, drilled at every bolt to be used as the washer between lid and nuts. This gives the lid the extra rigidity, only where it's needed at the edge. To save space, the leg of the angle that doesnt get drilled could face downward, toward the hull. Good choice on the 6061 bolts.
Another option is to use Viton O-Ring under the bolthead or under you square washer instead of the fiber washer. We use them under a bolthead of the bolt that secures the valve cover for a RotorWay A600 homebuilt helicopter and it works great!
Brian, try dome anchor nuts P/N NAS1473A3. This is what is used in aircraft fuel tanks. The 3 represents a 3/16 bolt and 4 would be 1/4 inch. If you want metric sizes you can probably find these as well.
Seems like you got it pardon me for commenting before the end! 1/8 G10 would make a nice inert washer. I use a hole saw to make custom washers, g10 or otherwise. If your bolts at 1/4” diameter then too easy, but you could get a larger drill bit into a hole saw mandrill without too much trouble, especially if your mates with a welder. And ut would seem prudent to use a torque setting on those bolts to A) ensure even gasket pressure, and B) to protect the aluminium bolts, as they will be very easy to damage. Also, hopefully the grade of aluminium in the bolts doesn’t waste away the plate or vice versa. Bronze can gobble up brass with ease and there might be similar considerations with different alloys of aluminium…
11:33 - why dont you just stud weld short threaded rods onto the top of the tank and ditch through-holes altogether? That way you dont nee a flange or to compromise the tank seal.
I agree with some other comments here about this width being too much. A thicker material but much more narrow in width will allow the pressure to build much higher in a smaller area, forcing the gasket to form to the space, rather than the metal flexing due to compressing too much surface area.. You might also go for some kind of liquid gasket at the same time for the underside of the gasket which won't need to be removed. Some kind of liquid silicone gasket too would do it, even the bolts. Also, a finer thread pitch along with Buna o-rings will eliminate the bolt leak issues. Amazing how far you far you guys have come already! You got this!👍
I’m thinking of several solutions: As mentioned before, using a cork gasket (it's excellent in this case) or a nitrile O-ring gasket (more complicated to make), and my preference, by far, is using a bladder, which is reliable, practical, and safe. The planned solution for this tank is not ideal, nor reliable, and could even be dangerous due to potential gas leaks.
I would suggest a O-Ring on the inside of the bolts with a recess milled from the tank to house the O-ring, we have had this work for many years on transformer tanks, the O-Ring is cheap and easy to repair.
Your aluminum boat has a natural oxide layer that protects it. That's why you don't need to paint it above the waterline. If you do decide to paint it above the waterline than the paint will not last more than around five years and then you need to remove all the paint above the waterline and paint it again. You'll be able to see the paint bubbling and water will be trapped behind the paint which causes corrosion. You don't want to let the bubbled paint stay like that for that long as well and that's why I'll be going with the bear aluminum look on my aluminum boat but with painted decks so that I don't slip when walking. I assume that the oxide layer or passivization works the same way on the aluminum anodes. The unpainted surface above the waterline of an aluminum boat itself doesn't need to be cleaned at all but the aluminum anodes do with probably wet sandpaper or maybe just a simple bristle brush just to get that natural oxide layer off of it. That's my best guess. Hopefully that helps a little bit anyways. Sailing Life on Jupiter has never taken off the bottom paint because the bottom paint doesn't bubble like it would above the waterline. One of the things that you do want to paint according to what Jamie said in one of his videos was the inside of the hulls below the waterline due to dried salt. You don't want salt on the inside of your bear aluminum boat unless you plan on washing it every three months to keep the salt off of the bear aluminum. It's a pain in the ass to clean it so that's why Jamie is going to paint the bottom of his hulls below the waterline. Above the waterline he has spray foam stuck to bear aluminum and as far as I know, that works well with no issue.
The small hatch for delivery, monitors and suction to engine is only 1/3 the size of a tank lid. There are three large lids over the long tank (10 ft?). Hull ribs are also present. As such, you would be unable to inspect or clean this tank.
You're basically building a monocoque airframe that floats. Use the same sealant that the aerospace industry uses to seal aircraft fuel tanks. Also use dome nuts for the plate fasteners. They self seal when installed.
It's a delight to see how professionals like Kurt and Dan. fabricate and handle the TIG welding for the sacrificial anode pockets and other sections of the boat. You are lucky to have such builders for Delos. It looks easy, but I can assure you it requires years to come close to producing strong-quality welds like that. Cheers.
As Brian and I discussed last week, the issue is not the gaskets but the nylon studs and nuts he's using. They simply do not generate the compressive pressure to properly seal the gaskets. It's an entirely understandable error given that he was wisely trying to avoid galvanic corrosion between steel bolts and the aluminum hull. However, two things should be considered: not only is nylon not strong enough as a fastener, it deforms with heat and also absorbs water over time. It swells and weakens as it does so. So anyone thinking of using Nylon in a damp/wet area should be careful, especially if consider using it as a bearing material (e.g. plastic bushes). If it were me, I'd have welded aluminum bolts into the hull holes. Welding them seals the bolts in the holes and holds them while you come to tighten the nuts above. Just be sure to check the torque settings before wrenching them up too tightly and stripping them!! Using a combination of aluminum washers and nuts is also wise A retaining compound like loctite is also recommended on the threads to prevent the nuts from slackening over time due to vibration and/or heat/cold cycling. Yes, engineering can get this detail oriented!
Welded bolts are a very good solution in part, however, you’ve already discovered the sheet metal is not thick enough with the type of gasket being used because tightening the bolts creates leaks in the gasket so bolts will solve problem one problem, but exacerbate problem two. I personally think the concept of The aluminum tank with multiple bolted lids is the issue. All the solutions tried so far have assumed that that’s a requirement, rather than challenging that assumption. And these are simple dry tests nothing like what will happen at sea. Consider the forces on those hulls and the fact that well under a millimeter gap in that gasket will generate leaks . For me personally, I would not risk this type of failure at sea. There will be an incredible amount of torque and torsion on those lids. What can be worse than having a slow possibly unnoticed fuel leak beneath your living quarters? Why not a completely enclosed tank with only seals at the port, perhaps with baffling if you’re worried about slashing, or something modular as others have mentioned. First time writing and doing so 100% out of care and concern for your safety and that you may solve this in the short term but wind up with a major issue and repair after going to sea. Tons of respect and admiration for what you all are doing here.
@@ToddAlanSloane The metal is perfectly thick enough since the bolts are close enough together and the seal thick enough to spread the load sufficiently.
@@johncampbell9216 it looks like he solved the problem based on the end of the video. However, the metal being thin was part of the issue. The reason I suspected this is because when he did change the bolt so that he could really torque them down he started getting leaks between the boltsat the gasket
@@ToddAlanSloaneAt some stage access to the tanks will be needed to clear out dead bacteria that forms at the condensation/diesel interface and then drops down to the tank bottom as a grey sludge to eventually block filters - and in colder waters that condensation is accentuated due to the thermal gradient across the aluminium of the hull. This sludge will have to be scooped out manually If that does prove to be an an ongoing issue the large tank access covers will make installation of flexible bladder bags relatively easy
When we seal a bulkhead in a pond liner we have to put the liner between the bulkhead head flange and “tank” or nut or it will leak on the threads. Can you use some of your black sheet scrap to make gaskets for the bolt/“stud” head inside to the tank? This would keep the fuel(air) from getting to the threads allowing fuel (air) to spin around the threads. I have seen this happen in ponds we repaired when the bulkhead is installed incorrectly. I also would add angle aluminum inside the tank to strengthen the linear surface from flexing. In a car the fuel tank has a rolled edge before the flat, then the fuel pump also has a rolled edge to give linear stability.
On the underside of the lid, where it contacts the gasket, I would propose welding a narrow aluminum bar around the interior perimeter, extending inside the bolt holes. This design would ensure the seal is formed directly with the gasket, effectively preventing any exposure to the bolt holes. The bar wouldn't need to be overly thick, just sufficient to create a continuous, unified seal around the entire edge.
Brian, Wes again. Trust me when I say our wing tanks were just like yours. Only we we flying four engine turbo prop. Much bigger wet tanks that took up both wings. The rubber seal by itself will leak. With the fuel resistant putty no problem. Call an aircraft maintenance that works on larger wet tank wings.
I agree with sealant. The reason the bolts fail is that the gasket is on both sides of the bolts. When you bolt it down, if it is not super flat, like a engine head, the outboard side of the seal may contact first, leaving the inboard side of the seal with gaps that lead to the bolt holes. Similar to another comment, a thinner sealing bead or gasket (or both) on the inboard side only of the bolt holes has a better chance of success
Hi, on the topic of anode and passivation of the Al-Zn-In anode, I think it would take a year or longer for it to become fully passivated. It ofc depends on temperature, salinity, etc.
Something to try, epoxy the bolts into the tanks from the inside by tightning the nuts from the top. Once epoxy has hardened fit the lid back with the nitrale gasket. Just a thought ...... good luck.
When cleaning corrosion off the anodes, you may have to remove them and clean all the mating surfaces as well. Aluminum house wiring has to be terminated in clamp connectors with an anti-corrosion grease that still makes good electrical contact. I dont know what is required for boat anodes.
Idea - Four pieces of aluminum angle bar or u-channel with holes drilled at spacing equally to the bolt pattern to make clamping pieces to hold down the lid. Place a nitrile gasket under the clamp pieces. The angle in the bar will add significant strength to the clamp (rather than a washer) and will spread out the clamping force along the edge of the aluminum.
Urethane windshield calk is what you need to seal the bolts and gasket. I would remove the studs and use bolts put calk on the threads to seal it. Glue the gasket to the tank with calk or don’t even use a gasket as the calk will be the gasket. When you need to remove the cover just use long razor blade and lube it with silicone to cut the bond between lid and tank. Same way they remove a windshield. That’s why you use bolts and not studs so you can cut the seal easily.
Too much risk to thread damage, can't easily replace at sea. Two issues were obvious can't use bolts with 100% thread, can't use plastic washers and for gosh's sake don't make ALL the hatches at once until you prove at 1 WORKS.
Simple solution - original lifted flange design with a fully welded, no bolts inset for the fuel fill/supply/return/sender/vent (FFSRSV). It also contains small spills around the FFSRSV. Heck, you could even put a leak sensor there. Never EVER try to seal around bolts unless you zero other choice.
I have experience with gaskets on gas tight windows for glove boxes. It looks like you are using a simple wrench to tighten the screws (maybe I am wrong). In my experience you need to use a torque wrench to ensure equal pressure across the gasket. I also think you need a stiffer gasket so that the pressure from individual screws is distributed rather than localized. Also, we usually add silicone to make a final seal.
Can you make an inner "ridge" on the fuel tank deck plate (The one stuck to the framework). This ridge is close to the actual larger hole and inside of the lines of bults. Over this you place the rubber gasket mat. On the loose larger hatch you make a similar ridge on the side towards the fuel that are placed between the deck plats upward turned ridge and the line of bolts. Between the "Inner upturned ridge" and the "outer downturned ridge" I would try a 75% distance of the thickness of the rubber gasket mat. That way you will have a much stronger sealent as the rubber Zig-zag between the ridges and your downforce by tighten the bolts will ground the rubber gasket mat to the deck plate.
The flange is the most proven way to secure a pressure vessel hatch this size and allow ease of service for the bolts that’s secure it. To preserve the floor heights have you consider inverting the flange inside the tank instead of the flange protruding above it?
I am in the petroleum business. What I have done is placed a nitrile or buna oring on the through bolt in side. So it would go bolt then flat washer and the an oring you roll down the bolt and then place it through the hole. Place in the gasket on the outside then bot down. Should have no leaks.
Regarding stray currents, please have a look at the channel Gone with the Wynns. They bought a brand new boat from a new boat building company and had nightmare problems with stray currents eating up all metal parts of their boat. I feel so sorry for them. It’s valuable to have seen what a faultily designed electrical system can do to a boat with a conducting hull (carbon fibre in their case).
Diesel will expand and contract and absorb water from air. You should have a vent system for those tank that doesn't place pressure on the gaskets or fasteners. You can create external clamps to fasten the lids down so you have no physical holes or penetrations in the tank to leak.
Machine groove in top, buy roll of nitrile o ring material glue o ring in reciever groove use silkaflex to seal but ends of o ring.bolt down and be done, keep roll of oring material on boat for repairs. Put o ring inside of studs not outside.
With petroleum applications, when sealing tanks, Permatex makes some great products one can apply on the gaskets and bolts to create a complete seal. Over tightening a rubber gasket only makes the leak worse. Good luck
Check out Click Bond. They have blind nut plates that are specifically meant for this. Fuel rated and secured with epoxy. No welding so it eliminates warpage on the seal surface. Probably wouldn’t hurt to have compression limiters on the bolts to prevent over torquing the seal too.
Brian and Kaza, I have really loved watching your adventures for many years. I know you probably get tired of hearing everyones opinions about things, but I just have to comment on your tank problem. I think having so many bolt holes in every tank is just not the best approach going forward. I think the original design should be made with the raised flanges that have holes that don't penetrate the tank at all, just like the smaller inspection hatch you made. Then, have the lid drop in elevation over the tank to fit the inspection hatch and necessary sender units, etc. A cross section would resemble a shallow top hat which is upside down. With this design, there would be zero bolt holes to seal, instead of 20-30. Simple is best, right?
I would go with the raised flanges throughout and have a recessed box section that will allow you to drop the nozzels etc that would foul the floor boards.
And this is the main reason many boats (mine included) that have plastic tanks for both diesel and water. Only have to seal the main line and one small air vent both of which are international pipe thread.
Brian, I would really consider having a separate fuel tank. You sont want to have to deal with flexing structures and sealing those. Sure, you'll lose some fuel capacity but is that really a big deal in the big picture?
Gaskets fail. I like the thought of some sort of bladder tank or lining. It would give some sort of double wall effect. Extra strength, insulation, flexibility and a sort of automatic leak protection. Ready Containment in Palmetto, FL makes custom diesel bladders. Might give them a call.
You are probably getting some flex on the thinner aluminum lids. I would have thicker lids machined and get an oring groove machined inside of the bolt holes so you don't need to worry about sealing them.
What about doubling the amount of bolts & reinforcing the top section between each bolt so the defamation and bending of the top plate is minimized? Looks like the leaks were mostly between each bolt.
23:15...POI, Just an old bucklenuster here. Lid thickness 3/8"? Every ICE head I've installed has had a tightening sequence. I would at least try an opposing sequence and see if that helps.
Hi Brian,
I've been working in the heavy truck industry for almost 3 decades. We use loctite 5699 to seal rear carriers to the axle housing, the holes are tapped into the axle housing, and the carrier is bolted to the housing, very similar to how you have your tanks set up. The good thing about using this sealant, it can be also added to your threads to help seal around the bolts. We pressure test out axles at 8psi, and this stuff holds every time. It is oil, water, and glycol resistant, and is NSF. We buy the large caulk tubes, and use a caulking gun to apply it, makes things easier. Good luck with whatever you decide. The new boat is looking great!
Thank you so much Kurt for helping build Delos 2.0 -- you will always be a part of this Tribe!
We installed a small window in the hull just for viewing the prop/rudder area. When kept clear it proved very useful for viewing what had got wrapped around what. If Delos 2 is cruising cold murky kelp and fishing line infested waters with two sets of sterngear to consider you might consider welding in stackpipes that extend higher than the waterline to allow an action cam on a pole to be lowered for examining sterngear and keel without having to first go overboard
Hi, I have a suggestion for your fuel tanks --> Check out how Single Engine or Multiengine trainer aircrafts store fuel in their wings. If I'm not wrong they store fuel in "bladders". Moreover, I notice that when you are trying to seal your fuel tanks you are doing it from the outside. Note that when fumes accumulate in your tanks they will have a propensity to exert outward pressure from within. So note that even in balloon or tubeless car tyres they use a sealant powder to guard against leaking punctures and they use soap and a perfect fit iron gasket seal within the tyre extremities to fit perfectly in the rim. Now you can't use a sealant as it will contaminate the fuel itself. If I were you I would still go in for the "bladder" fuel tank approach. This would drastically reduce the possible number of structural manufacturing defects to 2 - one, the bladder and nozzle seal and two, the nozzle itself. The only other possible operational defect would be one or more punctures. In your current approach, each of the nuts and bolts is a possible defect in addition to the gasket. A gasket is used in the engine manifolds but not the fuel tanks as there you have metal meeting metal which requires a seal which cannot be avoided. But in your fuel tank you can avoid this in the design itself. Even the Refueling heavy aircraft use bladders to store fuel in bulk for their client F-16 or B-2 or Falcon clients. My friend, forgive my bluntness but I think your approach is seriously flawed due to the number of possible defects in your design. Please reduce the number of possible defects in your design.
Bladders are absolutely the way to go here I think.
You just know Riley is glued to this video somewhere in Japan.
If Riley had chosen this design and this build method, it is likely that when the collision occurred the other boat would’ve been damaged and this boat would’ve been intact.
@@cwgarrif Riley had half a brain unblemished by massive ego, he wouldn’t have bought that dumbass boat.
You may think about looking into methods and materials for sealing aircraft wet wing tanks.
We use bladders for that.
Gaining experience is always a long, laborous and expensive adventure. As an aviation mechanic (Electrical-electronic) it would always take me 2 years of a 3-year tour learning the aircraft (ie getting experienced) b4 I could routinely troubleshoot the systems and get it right the first time. It is a glorious feeling to be in that space. Brian, the lessons you are putting on video are invaluable! Thank you and Kazz, you guys are awesome!
I have found in my industrial career that a wider gasket is not as good as a narrow gasket, think of the PSI (pounds per sq inch), more square inches is less PSI while less square inches of gasket equals a higher psi. The Teadit or Gore Tex as we called it should have been perfect fort this application
Pat
Got a valid point there.
I would also suggest BOLTS CLOSER to each other to have a more evenly spread pressure on that Aluminum.
I said the same in episode before this
Great to see you have found the solution to the tank Brian. Now to go forward. Keep our dream alive.
First Like! Love the Delos crew. I had a similar upbringing as Sierra's, my dad converted an old bus into a mobile home and we spent the first 15 years of my life, I traveled throughout Europe, Africa and the US. Almost completely home schooled. On land vs the sea, but similar traveling experiences. I am so happy to see how Sierra is growing up, she is experiencing wonderful things and will keep these memories with her forever.
I love the way Delos 2.0 is coming along, Brian's capacity for engineering and finding creative solutions is so entertaining! I also like how Kazza contributes to the buildout in the living spaces of the ship. I've binge-watched every video Delos has released, simply fascinating in all regards. Go Delos!
Warning!!! Aluminum doe NOT have a fatigue limit like stainless. The Aluminum bolts will stretch and loosen over time!!! I HIGHLY recommend replacing them with stainless bolts...The only issue with your fuel lid was that it needed a stiffener about 1/2" (11mm) x 1(25mm)" wide welded to the top edge where the boats go through... Would have solved all of the issues and I would have use a liquid sealant material. It will also minimize any galvanic corrosion. (just the opinion of an old grouchy engineer)
consider counter sinking the fuel pump mounting surface down lower in the lid to allow for the extra room needed while using the raised flange style on top of the tank.
Consider using two-part aviation fuel tank sealer. I used to repair 3 marine diesel tanks 14 years ago. I used rivits while the sealant was setting. Use for the large panel..
The problem is that the bolts themselves are not sealed. Either weld the ends inside the tank or use rubber washers for the bolts inside the tank.
For Your fuel tanks, use barrel nuts and use a sealant such as 8802. That is what we used on aircraft hatches. There should be a sealant that is water safe also. The barrel nuts are usually riveted on. Then use the seals you have for the hatch lid.
Flex, flex, flex! Use screws from the top into closed rivnuts installed in the tank flange. You need twice as many screws as you have now. Use MIL-PRF-81733D (B1/2) to seal the tank and flex and leaks will no longer be an issue.
Brione, just a thought; even if you sealed the tanks, the flex of the boat underway will create deformations. What about molded/removable tanks?
Wasting your time , he never listens
She's might just be the most humble Fans.greatly.BEAUTY and heartwarming person to exist💓
Glad you got the tanks figured out. Custom work sure is a challenge but you guys can do it! 👍❤
Not the end of this story yet not by a long chalk......
17:52 Use the same idea here for the tank covers. Cut some slugs out of bar stock drill and tap them, then drill holes in the tank and weld tapped slugs in the tank top and grind flush, and than bolts will be sealed.
What a journey! So glad you are sharing all this with us 🙂
You're designing a flaw right into your new boat. Custom made poly capsules for sure. Worth every cent.
ya that is my idea also, it would work perfect.
I was wondering if there is a reason why not to use a custom poly fuel cell.
Agreed, they will likely list this as one of thier biggest regrets of things they did during thier build in a few years.
@@DataRew judging from all the comments on this video and past ones - im thinking this boat is going to be a mess?
I've been through this exact problem with a hydraulic oil tank and trust me you ain't done, yes you might have a seal now with what you've done but it's not reliable and it will leak again. I finally sealed mine by welding 12mm thickening flanges around all the openings, that means welding the inside and outside edges to the tank so there is no path to the bolt holes in the thickening flanges which you should drill and tap before welding them on. Weld up and clean back the existing holes in the tanks first before welding the thickening flanges on so the finished fastening holes are essentially blind tapped holes. Red loctite studs into the flanges don't use bolts. Yes you now have 10mm plate lids, I would have used 12mm. Torque the fastening nuts so clamping pressure is even. Consider making a test rig to check deformation on the 10mm plate lid, just jazz it up with some off cuts and include the rubber gasket material, make it about 4 bolts long at the bolt centers you have chosen for the tanks, torque it up in stages, evenly and measure the deformation with a vernier so you know what the torque limit is without deformation. It is possible you might need to double up on the studs for the fuel tank and of course the flanges would need to have the extra holes drilled and tapped before welding down. A bit of a dribble on a water tank is annoying but a leak on a diesel tank is a pain in the arse, remember diesel is quite capable of finding a hole in a glass bottle with a screw on lid and a drip go's a mile, hydraulic oil is worse it go's about 2 mile.
Delos 2.0 is going to be AWESOME!!!! Can’t wait for the episode series where your daughter sails YOU around the world on its 20th trip around:)
Every release is a little masterpiece. Thank you for your hard work and love!🎩🏹🧃
Brian, great job getting those tanks sealed. As with all projects, sometimes the best thing to do is take a step back, get your mind off of it, and let the solution come to you. Sometimes, the closer you are to something, the less you can see!
Loved the aluminum washer idea. I can see how torquing those nylon washers down would cause deformation. And yes, the fiber washers are a great idea. I use them on my boat engine carb (I have an Atomic 4 engine. Great engine, if you stay on top of the fuel system and properly vent engine compartment). Also, good idea switching to the aluminum bolts. I know they're not as strong as stainless but like you said, this isn't a high torque area. You just need something that keeps a stead pressure on the lid and gasket.
About the only other solution would have been your idea of building a lip to weld to the tanks and then bolt the tank lids, but you didn't have clearance between them and the floor. About the only idea I had for that was to raise the floor up a few inches, but that would probably mess with something else! Congrats guys and good work!
On our Vans Aircraft aluminum fuel tanks we use proseal a two part mix.
Cures in a few days, never hardens - fills in the uneven surface.
Might look into it.
pro seal is being replaced by this sealant: part # MC-236-B2
The problem is the lidd and the tanktopp, they are only made of thin aluminium plates. They are not stiff enough, they flex when you are tigthening the bolts. And the more you tights, the more they flex. You must make the tanktopp and the hatches stiffer by welding on an additional strip of aluminium.
SkipPer
The original design had a much stiffer hatch opening , that got canned to reduce the height. I commented last weeks video they should keep the stiff hatch opening but the flange inside the tank instead of on top, to get the height they want, and that lid needs thicker rim as well.
Love you guys being in Oz, Friday night beers and sv delos vids are better then Saturday vids
Hi Brian
I worked as an engineer repairing and installing petrol and diesel pumps for many years.
We used sheets of Cork to make gaskets. Lay the Cork over the top of your tank and cut your gasket using a small ballpoint hammer, tapping gently around the edges cuts the gasket to perfect size.
Good luck.
He's right. Cork is one of the best gasket materials there is. Only way to beat cork is with O-rings set in grooves machined with a ball mill. EPDM is pretty great too though.
Cork was used many year ago ,there must be a better material .Rubber is often to "hard" any type of flexibel material,dieselresistent ,must be usefull.
It will not work as the flange is way to big. The bold-hole start leaking and wil do as the boat is flexing and or temperatures will work the panel. Cork or even paper will work with thick flanges like on pumps .
But these panels are suck. Way to large
Exactly, Machinist Engineer here that deals with custom gaskets and seals all the time. You have to understand the fundamentals of what a gasket does, and how it works. It's main job is to take up the inconsistencies and variances in gap in two mating surfaces. You may think you have two flat plates you are working with. They are not flat.
In order for the gasket to work you have to achieve 2 things, 1 adequate clamping force, and 2 rigidity of the mating surfaces when those clamping forces are applied. Your problems right now are that 1 you do not have adequate clamping force for the material type and width you are using, in PSI, and 2, you are getting localized deformation at each fastener location as they are spread too far apart.
Cork solves this as it is a much more compressible material than nitrile sheet. Secondly, a wider gasket is not necessarily better, Wider gaskets have more surface area, more surface area means greater forces need to be applied overall to achieve adequate deformation psi.
This is why o-rings work so well, the clamping force is concentrated in a very small cross section of the gasket material meaning it can easily deform to the contours it needs to seal against.
@@JimmyJamesJ Agreed and EPDM is just about the standard for food contact. You still need enough rigidity in the flange to minimise distortion.
Bladder tanks,as in aircraft wings?
Consider taking a 2" strip of metal and weld it to the back of the fuel tank lid @ 90 degrees (short it so the lide gasket is not even close). Think baffles, but on the lid. Stiffens the lid by a ton, quiets the tank, adds only a little weight. Keep up all the awesome teamwork, you guys are doing great. Know your/you're love
Hey Captain...25 plus years in the metal trades...you need to stiffen your cover plat for your fuel tanks...or any tanks...aluminum is not stiff, hard, or how ever you wish to describe it a piece of angle around the out side edge...flange up...drill and tap should work fine...ask you ship builder how he sealed his tanks...unless they weren't built in....
One of your viewers mentioned aircraft wings. I was in Naval Aviation flight crew. We had wet wings and constantly had to inspect our fuel cells. We had sealant mixture that was a brown putty . Like a permatex. Natural the wings were aluminum. And if we had a rivet leaking that’s how we would seal it from the inside. Crawl inside and putty around the rivet.
Do your fuel tanks use breathers? For example, in a truck differential, driving through cold water causes the diff and contents to contract and create negative pressure, sucking in water. A diff breather is a tube from the cavity up far above water level, open to the air with a tiny filter on the end, to allow dry pressure equalization. In your case, as you use fuel (or water) you are going to need to let air into the tanks, unless you use a bladder. Your tanks thus need a breather tube up out of the inhabited spaces to somewhere outside well above water level, venting in such a way as to prevent fire or inhalation risk from the fumes.
Yes, there are 16mm ID breather tubes. Also to let air out when you are filling.
Coming right along. Sealing tanks can be a serious chore sometimes. Keep up the good work and will see you in the next episode!
Hey guys .... those anode recessed boxes are a granite idea for hydrodynamic but in my experience if the stray currents have to take any sort of corner they hit the sharp corners next to the anode... I would suggest rounding the corners where the box meets the hull on the outside and also put a big fillet well on the inside to give it more thickness just in case...because it will become a concentrated area of electrons .... grate build I'm love you channel ...
Have you thought about welding in aluminum female threaded inserts? So that the bolts themselves do not have to be sealed, it would just be the cover and tank then. Just like the original flanged plan.
seems like you're trying to use a mechanical solution to fastening the bolt to the tank. why not weld on the bolts to a flange plate outside of the sealed area.
ha! should have waited for the end. Congrats on the solution!
glad you figured it out! great job
What’s wrong with flexible fuel tanks, like in Aircraft?
Exactly what I was thinking. As a mech on H3 and H60 helos, which are essentially the same construction as that aluminum boat, the fuel bladders could be deflated, stuffed into any irregular shaped vessel hold, and filled up with no leaks.
@@uncleansanchez How well would the bladders shape around the the ribs of the hull that are present in this Cat?
@@philipmackin1025works in Aircraft!
I was recalling my experience with aircraft like the H60 series self sealing fuel tank bladders.
To save weight on the tank lid: you could combine the thinner lid with angle 6061, drilled at every bolt to be used as the washer between lid and nuts. This gives the lid the extra rigidity, only where it's needed at the edge. To save space, the leg of the angle that doesnt get drilled could face downward, toward the hull. Good choice on the 6061 bolts.
Another option is to use Viton O-Ring under the bolthead or under you square washer instead of the fiber washer.
We use them under a bolthead of the bolt that secures the valve cover for a RotorWay A600 homebuilt helicopter and it works great!
Brian, try dome anchor nuts P/N NAS1473A3. This is what is used in aircraft fuel tanks. The 3 represents a 3/16 bolt and 4 would be 1/4 inch. If you want metric sizes you can probably find these as well.
Seems like you got it pardon me for commenting before the end!
1/8 G10 would make a nice inert washer. I use a hole saw to make custom washers, g10 or otherwise. If your bolts at 1/4” diameter then too easy, but you could get a larger drill bit into a hole saw mandrill without too much trouble, especially if your mates with a welder.
And ut would seem prudent to use a torque setting on those bolts to A) ensure even gasket pressure, and B) to protect the aluminium bolts, as they will be very easy to damage.
Also, hopefully the grade of aluminium in the bolts doesn’t waste away the plate or vice versa. Bronze can gobble up brass with ease and there might be similar considerations with different alloys of aluminium…
11:33 - why dont you just stud weld short threaded rods onto the top of the tank and ditch through-holes altogether? That way you dont nee a flange or to compromise the tank seal.
For some odd reason if the needed to access the tank, they can't
Brian & Kazza, thanks for sharing your adventure and progress. YOU GUYS ROCK!❤❤❤
I agree with some other comments here about this width being too much. A thicker material but much more narrow in width will allow the pressure to build much higher in a smaller area, forcing the gasket to form to the space, rather than the metal flexing due to compressing too much surface area.. You might also go for some kind of liquid gasket at the same time for the underside of the gasket which won't need to be removed. Some kind of liquid silicone gasket too would do it, even the bolts. Also, a finer thread pitch along with Buna o-rings will eliminate the bolt leak issues. Amazing how far you far you guys have come already! You got this!👍
Oh I wasn't expecting the solution at the end..lol 🤣👍
I’m thinking of several solutions: As mentioned before, using a cork gasket (it's excellent in this case) or a nitrile O-ring gasket (more complicated to make), and my preference, by far, is using a bladder, which is reliable, practical, and safe. The planned solution for this tank is not ideal, nor reliable, and could even be dangerous due to potential gas leaks.
I would suggest a O-Ring on the inside of the bolts with a recess milled from the tank to house the O-ring, we have had this work for many years on transformer tanks, the O-Ring is cheap and easy to repair.
Hope it all works out in the long run !!
Your aluminum boat has a natural oxide layer that protects it. That's why you don't need to paint it above the waterline. If you do decide to paint it above the waterline than the paint will not last more than around five years and then you need to remove all the paint above the waterline and paint it again. You'll be able to see the paint bubbling and water will be trapped behind the paint which causes corrosion. You don't want to let the bubbled paint stay like that for that long as well and that's why I'll be going with the bear aluminum look on my aluminum boat but with painted decks so that I don't slip when walking. I assume that the oxide layer or passivization works the same way on the aluminum anodes. The unpainted surface above the waterline of an aluminum boat itself doesn't need to be cleaned at all but the aluminum anodes do with probably wet sandpaper or maybe just a simple bristle brush just to get that natural oxide layer off of it. That's my best guess. Hopefully that helps a little bit anyways. Sailing Life on Jupiter has never taken off the bottom paint because the bottom paint doesn't bubble like it would above the waterline. One of the things that you do want to paint according to what Jamie said in one of his videos was the inside of the hulls below the waterline due to dried salt. You don't want salt on the inside of your bear aluminum boat unless you plan on washing it every three months to keep the salt off of the bear aluminum. It's a pain in the ass to clean it so that's why Jamie is going to paint the bottom of his hulls below the waterline. Above the waterline he has spray foam stuck to bear aluminum and as far as I know, that works well with no issue.
Weld down the big hatch, the small hatch is big enough to clean the tank if necessary.
The small hatch for delivery, monitors and suction to engine is only 1/3 the size of a tank lid.
There are three large lids over the long tank (10 ft?).
Hull ribs are also present. As such, you would be unable to inspect or clean this tank.
Very well done. Thank you for sharing.
You're basically building a monocoque airframe that floats. Use the same sealant that the aerospace industry uses to seal aircraft fuel tanks. Also use dome nuts for the plate fasteners. They self seal when installed.
It's a delight to see how professionals like Kurt and Dan. fabricate and handle the TIG welding for the sacrificial anode pockets and other sections of the boat. You are lucky to have such builders for Delos. It looks easy, but I can assure you it requires years to come close to producing strong-quality welds like that. Cheers.
As Brian and I discussed last week, the issue is not the gaskets but the nylon studs and nuts he's using. They simply do not generate the compressive pressure to properly seal the gaskets. It's an entirely understandable error given that he was wisely trying to avoid galvanic corrosion between steel bolts and the aluminum hull. However, two things should be considered: not only is nylon not strong enough as a fastener, it deforms with heat and also absorbs water over time. It swells and weakens as it does so. So anyone thinking of using Nylon in a damp/wet area should be careful, especially if consider using it as a bearing material (e.g. plastic bushes).
If it were me, I'd have welded aluminum bolts into the hull holes. Welding them seals the bolts in the holes and holds them while you come to tighten the nuts above. Just be sure to check the torque settings before wrenching them up too tightly and stripping them!! Using a combination of aluminum washers and nuts is also wise A retaining compound like loctite is also recommended on the threads to prevent the nuts from slackening over time due to vibration and/or heat/cold cycling. Yes, engineering can get this detail oriented!
Welded bolts are a very good solution in part, however, you’ve already discovered the sheet metal is not thick enough with the type of gasket being used because tightening the bolts creates leaks in the gasket so bolts will solve problem one problem, but exacerbate problem two. I personally think the concept of The aluminum tank with multiple bolted lids is the issue. All the solutions tried so far have assumed that that’s a requirement, rather than challenging that assumption. And these are simple dry tests nothing like what will happen at sea. Consider the forces on those hulls and the fact that well under a millimeter gap in that gasket will generate leaks . For me personally, I would not risk this type of failure at sea. There will be an incredible amount of torque and torsion on those lids. What can be worse than having a slow possibly unnoticed fuel leak beneath your living quarters? Why not a completely enclosed tank with only seals at the port, perhaps with baffling if you’re worried about slashing, or something modular as others have mentioned. First time writing and doing so 100% out of care and concern for your safety and that you may solve this in the short term but wind up with a major issue and repair after going to sea.
Tons of respect and admiration for what you all are doing here.
@@ToddAlanSloane The metal is perfectly thick enough since the bolts are close enough together and the seal thick enough to spread the load sufficiently.
@@johncampbell9216 it looks like he solved the problem based on the end of the video. However, the metal being thin was part of the issue. The reason I suspected this is because when he did change the bolt so that he could really torque them down he started getting leaks between the boltsat the gasket
@@ToddAlanSloaneAt some stage access to the tanks will be needed to clear out dead bacteria that forms at the condensation/diesel interface and then drops down to the tank bottom as a grey sludge to eventually block filters - and in colder waters that condensation is accentuated due to the thermal gradient across the aluminium of the hull. This sludge will have to be scooped out manually
If that does prove to be an an ongoing issue the large tank access covers will make installation of flexible bladder bags relatively easy
@@ToddAlanSloane It is possible to overtorque.
When we seal a bulkhead in a pond liner we have to put the liner between the bulkhead head flange and “tank” or nut or it will leak on the threads.
Can you use some of your black sheet scrap to make gaskets for the bolt/“stud” head inside to the tank?
This would keep the fuel(air) from getting to the threads allowing fuel (air) to spin around the threads. I have seen this happen in ponds we repaired when the bulkhead is installed incorrectly.
I also would add angle aluminum inside the tank to strengthen the linear surface from flexing. In a car the fuel tank has a rolled edge before the flat, then the fuel pump also has a rolled edge to give linear stability.
Spouted too soon.
Nice work.
On the underside of the lid, where it contacts the gasket, I would propose welding a narrow aluminum bar around the interior perimeter, extending inside the bolt holes. This design would ensure the seal is formed directly with the gasket, effectively preventing any exposure to the bolt holes. The bar wouldn't need to be overly thick, just sufficient to create a continuous, unified seal around the entire edge.
Brian, Wes again. Trust me when I say our wing tanks were just like yours. Only we we flying four engine turbo prop. Much bigger wet tanks that took up both wings. The rubber seal by itself will leak. With the fuel resistant putty no problem. Call an aircraft maintenance that works on larger wet tank wings.
Take a look SeaBilt inspection ports.
I agree with sealant. The reason the bolts fail is that the gasket is on both sides of the bolts. When you bolt it down, if it is not super flat, like a engine head, the outboard side of the seal may contact first, leaving the inboard side of the seal with gaps that lead to the bolt holes. Similar to another comment, a thinner sealing bead or gasket (or both) on the inboard side only of the bolt holes has a better chance of success
Hi, on the topic of anode and passivation of the Al-Zn-In anode, I think it would take a year or longer for it to become fully passivated. It ofc depends on temperature, salinity, etc.
Something to try, epoxy the bolts into the tanks from the inside by tightning the nuts from the top. Once epoxy has hardened fit the lid back with the nitrale gasket. Just a thought ...... good luck.
Delos 2.0 is awesome! Great job.
When cleaning corrosion off the anodes, you may have to remove them and clean all the mating surfaces as well.
Aluminum house wiring has to be terminated in clamp connectors with an anti-corrosion grease that still makes good electrical contact. I dont know what is required for boat anodes.
Idea - Four pieces of aluminum angle bar or u-channel with holes drilled at spacing equally to the bolt pattern to make clamping pieces to hold down the lid. Place a nitrile gasket under the clamp pieces.
The angle in the bar will add significant strength to the clamp (rather than a washer) and will spread out the clamping force along the edge of the aluminum.
Urethane windshield calk is what you need to seal the bolts and gasket. I would remove the studs and use bolts put calk on the threads to seal it. Glue the gasket to the tank with calk or don’t even use a gasket as the calk will be the gasket. When you need to remove the cover just use long razor blade and lube it with silicone to cut the bond between lid and tank. Same way they remove a windshield. That’s why you use bolts and not studs so you can cut the seal easily.
You could also try aluminum crush washers they are used to seal oil drain screws.
After every video I do the "Woo hoo!" with Sierra. I can't be the only one.
No, definitely not the only one!
Another great video!
Weld studs on the tankis sealed perfectly
Too much risk to thread damage, can't easily replace at sea.
Two issues were obvious can't use bolts with 100% thread, can't use plastic washers and for gosh's sake don't make ALL the hatches at once until you prove at 1 WORKS.
That’s why you install nutserts on tank side run bolts into tank if one fails you have new ones to install small kit keep on board
Simple solution - original lifted flange design with a fully welded, no bolts inset for the fuel fill/supply/return/sender/vent (FFSRSV). It also contains small spills around the FFSRSV. Heck, you could even put a leak sensor there. Never EVER try to seal around bolts unless you zero other choice.
I have experience with gaskets on gas tight windows for glove boxes. It looks like you are using a simple wrench to tighten the screws (maybe I am wrong). In my experience you need to use a torque wrench to ensure equal pressure across the gasket. I also think you need a stiffer gasket so that the pressure from individual screws is distributed rather than localized. Also, we usually add silicone to make a final seal.
Can you make an inner "ridge" on the fuel tank deck plate (The one stuck to the framework). This ridge is close to the actual larger hole and inside of the lines of bults. Over this you place the rubber gasket mat. On the loose larger hatch you make a similar ridge on the side towards the fuel that are placed between the deck plats upward turned ridge and the line of bolts. Between the "Inner upturned ridge" and the "outer downturned ridge" I would try a 75% distance of the thickness of the rubber gasket mat. That way you will have a much stronger sealent as the rubber Zig-zag between the ridges and your downforce by tighten the bolts will ground the rubber gasket mat to the deck plate.
The flange is the most proven way to secure a pressure vessel hatch this size and allow ease of service for the bolts that’s secure it. To preserve the floor heights have you consider inverting the flange inside the tank instead of the flange protruding above it?
I am in the petroleum business. What I have done is placed a nitrile or buna oring on the through bolt in side.
So it would go bolt then flat washer and the an oring you roll down the bolt and then place it through the hole. Place in the gasket on the outside then bot down. Should have no leaks.
Aluminium washers, very common in refrigeration. Heavy duty Ammonia plants use them as a crush washer for sealing.
Hey,
Good idea on buss bars..
I have seen thoses fail..
Moisture is the problem.
And stacking negative and positive is what jump out at me..
I have watch you all from the begining..
It is fascinating to see how much work you and the shipyard have accomplished in only eight months. As for the tanks congrats on finding a solution.
You could make washer from the gasket material that you would put at the bolt head inside the tank it will act as an O-ring
3-m above and below the water line
Works really well.
Make shur that vent on fuel tank is big enough!!! Awesome job guys
Regarding stray currents, please have a look at the channel Gone with the Wynns. They bought a brand new boat from a new boat building company and had nightmare problems with stray currents eating up all metal parts of their boat. I feel so sorry for them. It’s valuable to have seen what a faultily designed electrical system can do to a boat with a conducting hull (carbon fibre in their case).
Diesel will expand and contract and absorb water from air. You should have a vent system for those tank that doesn't place pressure on the gaskets or fasteners. You can create external clamps to fasten the lids down so you have no physical holes or penetrations in the tank to leak.
Machine groove in top, buy roll of nitrile o ring material glue o ring in reciever groove use silkaflex to seal but ends of o ring.bolt down and be done, keep roll of oring material on boat for repairs.
Put o ring inside of studs not outside.
With petroleum applications, when sealing tanks, Permatex makes some great products one can apply on the gaskets and bolts to create a complete seal. Over tightening a rubber gasket only makes the leak worse. Good luck
Check out Click Bond. They have blind nut plates that are specifically meant for this. Fuel rated and secured with epoxy. No welding so it eliminates warpage on the seal surface. Probably wouldn’t hurt to have compression limiters on the bolts to prevent over torquing the seal too.
The challenge of reinventing the wheel. Carry on.
Brian and Kaza, I have really loved watching your adventures for many years. I know you probably get tired of hearing everyones opinions about things, but I just have to comment on your tank problem. I think having so many bolt holes in every tank is just not the best approach going forward. I think the original design should be made with the raised flanges that have holes that don't penetrate the tank at all, just like the smaller inspection hatch you made. Then, have the lid drop in elevation over the tank to fit the inspection hatch and necessary sender units, etc. A cross section would resemble a shallow top hat which is upside down. With this design, there would be zero bolt holes to seal, instead of 20-30. Simple is best, right?
I would go with the raised flanges throughout and have a recessed box section that will allow you to drop the nozzels etc that would foul the floor boards.
And this is the main reason many boats (mine included) that have plastic tanks for both diesel and water. Only have to seal the main line and one small air vent both of which are international pipe thread.
Brian, I would really consider having a separate fuel tank. You sont want to have to deal with flexing structures and sealing those. Sure, you'll lose some fuel capacity but is that really a big deal in the big picture?
Quote of the year "Now we know another way it doesn't work!" Sounds like all my projects!!
I don't have the catalogue number to hand but Locktite make a super expensive diesel sealant. Just for the threads. Mark travelgnu
I love it when Kazza says "Forward Slash" svdelos.
Gaskets fail. I like the thought of some sort of bladder tank or lining. It would give some sort of double wall effect. Extra strength, insulation, flexibility and a sort of automatic leak protection. Ready Containment in Palmetto, FL makes custom diesel bladders. Might give them a call.
bladders fail just the same.
@@6226superhurricane Mine did at 2am this morning, at any rate.
@@6226superhurricane yes but theoretically would offer another layer of leak protection fitted into the aluminum tanks
You are probably getting some flex on the thinner aluminum lids. I would have thicker lids machined and get an oring groove machined inside of the bolt holes so you don't need to worry about sealing them.
Can you weld the bolts in place from inside the storage to prevent the leak around the bolt?
Since Dan and Kurt have finished their work this build is making me anxious.
What about doubling the amount of bolts & reinforcing the top section between each bolt so the defamation and bending of the top plate is minimized? Looks like the leaks were mostly between each bolt.
23:15...POI, Just an old bucklenuster here. Lid thickness 3/8"?
Every ICE head I've installed has had a tightening sequence. I would at least try an opposing sequence and see if that helps.