Steel vs Aluminum Tanks - Scuba Tech Tips: S03E07
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- Опубликовано: 21 мар 2016
- What are the differences between steel and aluminum scuba tanks? Alec explains the practical pros and cons of each tank plus how yoke and DIN valves fit into tank selection.
**** Alec Peirce Scuba ****
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Alec you are the man. Do you know how rare it is to have someone with 40+ years of experience in ANYTHING willing to participate on youtube or social media. Most people your age aren't interested in going online and volumes of knowledge are going to be lost. What a precious resource and fountain of knowledge you are. Thanks for making these videos, I'm learning things I didn't even know to ask about!
Wow! thanks for the kind words. Really I'm just having fun. Surely you can see that in the videos. And I figure that if I can make someone's diving a bit easier or safer it's the least I can do. Scuba diving has been a big part of my life, most of my life and I've had experiences that I can't begin to describe to you, experiences so awesome that I sometimes doubt my own memory. But they happened and it's been simply wonderful. I'm outa' soon and I'd like to at least leave something for other divers to enjoy and benefit from. Maybe these videos are it.
Thanks again. Alec
I like this guy. He has a fun personality, and I love how he is VERY cautious about saying better. I noticed that well before he even started talking about the DIN regulators.
Thanks Erikk, better is a subjective word as both tanks work fine. Its the individual preference/prejudice than comes out in these discussions, not what works for you.
@@AlecPeirceScuba_SeaHunter I completely agree. I like hearing peoples opinion, but to often "they" ("we" maybe? LOL) get opinions and facts mixed up.
I just have to say you are the greatest at explaining things and I have now watched all your videos and have incorporated many things you have said and I thank you for doing the videos
Wow! You've watched all of my videos?!!
You must be a Master Diver by now! LOL.
I'm glad it's been helpful and hopefully, entertaining too.
Alec
John Ramirez, i agree to the highest level!As a Filipino i sometimes have trouble understanding how Americans speak but he speaks and explain things clearly. He talks fast but i can understand! I love him already as my new mentor 👌
Every time I think of a question to ask Alec, he's already answered it in 2016.
I used steel tanks during my intial certification while living in Italy. Then after moving back to the US used aluminum 80's for the first time, hated it especially when the tank started becoming buoyant near the end of the dive.
You can imagine my frustration. I used steel tanks exclusively for 20 years before aluminum tanks appeared.
However, the improvement in the safety and the low maintenance of the aluminum tanks still makes the annoyance worthwhile.
It has been argued that the positive buoyancy of an aluminum tank at the end of a dive is a good thing but I agree with you. They are bouncy and tippy and make you feel like a beached whale.
Alec
Once again another informative video. There are very few people with you knowledge and experience wanting to share, keep it up Alec!
Great refresher tutorial Alec!! Thank you very much for your time.
Thanks for watching Kris.
Alec
thanks Alec!! I always look forward to your videos. they really make my day!!
As always, super-great. Thanks a million, Karl.
Great videos. I always learn something new when I watch these. Thank you!
I love all your videos Alec. Hope to dive with you one day!
Outstanding stuff!! So educational.
I just want to say thank you for all you videos, they are all helpful and expertly done. Very very educational.
You are indeed a very knowledgeable and very cool dude, even a bit modest, I might add. No I'm not from Hollywood. lol Keep up the good work my brother.
Enjoying the tech. Super great stuff. Thanks for sharing your knowledge.
Glad you enjoy it Tom.
I’m writing a term paper about the evolution of materials used to create diving tanks, and your channel has been quite useful to learn the basics of this equipment. I’m not personally a diver, so a quick educational video like these are a great start. Thanks.
Good. Glad to help.
It was an evolutionary process. The first were steel. They they added chromium to make them harder. But that also made them brittle so they added molybdenum to increase flexibility. And then aluminum came along.
But your term paper could get very complicated. since even aluminum tanks come in a dozen different alloys, each with its own characteristics. A few years ago, one of those alloys caused problems and some tanks actually exploded after much use. Obviously they had to change the alloy used.
As I said, it's been an evolutionary process with mistakes and improvements along the away.
Thanks for watching.
Alec
As always, very informative and entertaining. Can't thank you enough!
Thanks for watching. Alec
Thanks. Have really been enjoying your videos.
Alec thanks for the educational on tanks and yokes you seem like a layed back guy most people like you are wonderful instructors and the years of knowledge is priceless great video I just found you and will certainly be watching more thank you sir
I appreciate that!
This video, and your other videos are extremely helpful, thanks.
Glad you like them!
These are great friggin vids !! Thanks so much for the insight...As a new diver they have been super beneficial :)
I'm so glad they've been helpful.
Thanks for watching.
Alec
you are awesome for making these videos! Thank you!
Glad you like them!
Great stuff. Thank you Sir.
Thanks again for your time and commitment to making sure there’s plenty of good information. Just did my 1st 100 footer at Catalina. It was my 5th dive ever and absolutely amazing. Shark hanging out at 130. Now I’m gathering info on different equipment. Thinking about getting a 120 cause I’m still new and use a lot of air. #SignatureScuba is the club I joined and how I found your videos. We watched 1 at our last monthly meeting.
Well a steel 120 is a big tank if you want to shed lead from the BC. Glad to hear SignatureScuba show only the best videos!! I have lots they can show. I used to dive Catalina after each west coast DEMA show for many years. Say hi to SignatureScuba and compliment them on their excellent video picks. Thanks for watching Ryan.
You are a true wealth of knowledge, thanks, super-interesting.
Great video! Very informative on cylinders. I chose a DIN regulator because I prefer relying on the beefier o-ring that's in my possession rather than those thinner o-rings found on yoke rental tanks. My reg came with a yoke adapter so I'm set either way.
Hey great video, I’m a new diver and these videos are very helpful, keep it up!
Thanks Alex.
I hope you're getting some good ideas.
Alec
My auto-correct just tried to change your name to Alec!!!
Alec Peirce Scuba thanks for replying, nice to see a creator replying to his fans, this has helped me a lot in knowing how to be a good diver!
PS your really funny and makes the videos fun and also a learning experience, great job!
-Alex
Great information all divers can use. Alec has enough enthusiasm to keep me interested in the entire video. Wonderful work. Please keep it up. Sub'd
Thanks Still.
Alec
awesome job, thank you.
You sir are the Mr Rogers of Scuba 👍🏻👍🏻👍🏻👍🏻👍🏻
Hmmm. I've been compared to a lot of crazy people but that's the first time for Mr. Rogers.
I'm going to assume that's a compliment for which I thank you.
Alec
Thank you Alec! Would love to see a future tech tip about Fins. In an earlier tech tip you had one the scuba pro novas. Would love to hear you discuss fin styles paddle, split and full foot or your ideas about what to look for when in the market for upgrading your fins.
7:02 I was expecting you say "Kevin" lmao, as always, very informative, thank you.
Sir thank you for the tips you are a wonderful teacher :)
Thanks for watching Erick.
Alec
Great information thank-you for the info.
Glad it was helpful!
great video, thanks!
Thanks for watching.
Alec
your great thank for the info I am looking into scuba so it all helps
Glad to help.
Scuba diving is a wonderful adventure that will keep you amazed your whole life.
Don't hesitate. You will never regret trying scuba.
Good luck.
Alec
Alec, my understanding is that the main arena that DIN is considered "better" is when diving in an overhead environment such as wreck penetration, caves, caverns, ect. The idea is that if the 1st stage is bumped hard against the overhead it is less likely to be dislodged/leak with a DIN configuration than a Yoke configuration. For most recreational divers this is not an issue as the vast majority of recreational divers do not dive in an overhead environment. Also, it was great that you showed a DIN to Yoke valve adapter....viewers might also be interested in knowing that Yoke adapters for DIN type 1st stages exist too.
Cool channel mate 😉😉😉
Thanks Ruby.
Alec
Love your channel...
There are other reasons DIN is better. 1. Lower profile. 2. DIN can take an impact way better than a yoke. 3. And like you said Alec, hold back more PSI. 4 And we don't blow O rings like a yoke. So, yes in my opinion yoke is inferior to DIN. I think yoke should just be phased out.
Many think so but all of North America is yoke so its like trying to get American's to go metric! Metric is smart, simple and world wide but nope, it's not American so no changes.
I own 30 cylinders and 12 of them are steel "72s." In most cases 65 cubic feet is enough gas for a recreational divers, and properly cared for the 3AA low-pressure cylinders will far outlast aluminum cylinders. I would also put in a positive plug for hot dipped galvanized cylinders and am glad that Faber finally saw the light on that. I love diving with students (even much smaller people and easily out breathing them using my steel "72." Good video!
The steel 72 was my favorite tank by far, still is.
And you're quite right about galvanized tanks.
Alec
Great video. Thanks. The one of the other thing I will mention with using a DIN vs Yoke valve and regulator is that it has less of a chance of being knocked off. (Over head environments) Also after using both systems personally I have found I have less issues with DIN leaking or having O-ring issues over all. That said If you own an DIN regulator and plan on traveling you need an adapter and now you are dealing with two O-rings and a more comber-sum system if the rental tanks don't have a valve that is not convertible.
wonder if the reverse is true - if you travel to europe (plan on doing some diving back in my home town in France) and tanks are steel/DIN, do you all have yoke adapters ? (
Some places have Ali cylinders, but steel is the norm. The valve will normally have an insert so can be used with either DIN or yoke. The cylinders are usually described by their internal volume eg 12 Liter and would typically be filled to 232 bar. That's about 98CuFt many dive centers will also have 10l (80CuFt) and 15l cylinders (135CuFt)
This guy is great
A little louder please!!
I'm not sure if I'm great or just old and have done a lot of stuff.
I'm happy to share and I'm pleased that you're enjoying it.
Alec
Nice video as always. Can you make a video addressing how a steel is better when diving due to its buoyancy characteristics?
Working on it.
Alec
Just watched your video for the first time and love your teaching style. Reminds me of a psychology teacher I had in college. Last name was Salter. I called him salt dawg. Loved him to death. I've been scubaing for about four years now. Just bought my first dry suit and taking the class. I'm thinking really hard about going the professional route. I will continue following your teachings.
I dont mean to be so off topic but does someone know a method to log back into an Instagram account?
I stupidly forgot my password. I would love any tricks you can give me
@Zyaire Harlem Instablaster ;)
@Jaiden Salvatore Thanks for your reply. I found the site through google and im waiting for the hacking stuff now.
Looks like it's gonna take a while so I will reply here later when my account password hopefully is recovered.
@Jaiden Salvatore it worked and I now got access to my account again. I am so happy:D
Thank you so much you saved my account !
@Zyaire Harlem happy to help :D
Hi Alec, Was looking at tanks yesterday, so this is most helpful. I saw the Steel Faber tanks come HP High Pressure & Reg, some are Hot Dipped Galvanized with higher prices. Other question is on Aluminum tanks come in many colors however not the Steel tanks. A short answer will help me on both questions. Thank's Alec...
It's very hard to get paint to stick to galvanized.
It's hard to get paint to stick to aluminum too but they've mastered it now so the paint no longer flakes off in the first year.
I'm not sure how many tech divers would want hot pink tanks. They're too cool for that!!
Alec
DIN is Deutsches Institut für Normung (the German Institute for Standardization) which is Germany's organization that is part of the ISO standards group. A lot of ISO standards and many EU standards come from DIN originally (Like the DIN jack used for SVideo connections, the DIN connector used for the PC keyboard (both the original and more modern PS/2 smaller one before everything went USB) and also for MIDI connections for musical instruments, and many other things). Pretty much a lot like ANSI is in the US. The German's like standards. They make life better. :)
My understanding is that the DIN regulators come in both 5 thread (232Bar) and 7 thread (300Bar) versions, and that at least in Europe some people are using 300 Bar tanks (or near that, like 4500psi). The adaptable valve should be the 5 thread since you are not supposed to be able to convert a 300Bar to yoke of course. The regular with 7 thread will fit fine in a 5 thread valve, it just won't screw all the way in (which is fine and expected).
+Lennart Sorensen The reason the 232 bar DIN regulator has only 5 threads instead of 7 is so that it cannot be hooked up to a 300 bar tank valve...the regulator will not screw in enough to make a seal with the valve...this is to prevent damaging the regulator from the higher pressure than it is rated for.
There are not many DIN regulators on the market that are rating at 232 bar and most are at the entry level end of the spectrum such as the Aqualung Calypso. Since none of the international/yoke type valves are rated for 300 bar, any of the DIN regulators can be used on them with a yoke adapter.
The only thing to make sure of is that the correct yoke adapter is used with a 232 bar DIN reg. Some of the yoke adapters have 7 threads in them and again a 232 bar DIN reg will not screw in enough to make a seal. I learned this the hard way as my wife has a calypso regulator and we initially purchased the wrong yoke adapter for it. The 300 bar DIN regs will work fine with any of the yoke adapters.
The screw in adapter that Alec showed only has 5 threads and while it will screw into a 300 bar tank valve a yoke regulator or yoke adapter will not make contact with it to form a seal because it will be set in too far.
+Jeff Greenfield Yes it would be silly if the convertible vale had 7 threads since the 232bar 5 thread reg is plenty for a tank with such a valve. I have just used yoke so far, but I know my regulator is trivial to swap between yoke and DIN if I just got that piece for the regulator. Not sure if I will ever have a need for DIN given so far I have only done diving in Canada and the Caribbean where yoke seems to be what you always see.
+Lennart Sorensen I use Mares MR22/Abyss set up that I was able to get the DIN conversion kit very inexpensively (35 Euros). The benefit that I get from using DIN (I am currently stationed in Europe)...is that the 1st stage configuration is a bit lighter...while this doesn't mean anything when diving as the 1st stage is support by the tank...it makes a difference when packing for destination diving where airlines will charge ridiculous amounts of money if one is over the weight limit. This only works though if one's destination has tank valves that will accept DIN regulators....so far in my experience Egypt=yes, Philippines=yes, Thailand=no.
The DIN 1st stage and superflex hoses make for a nice light and compact travel set up. Also if travling with a DIN with Yoke adapter set up, the yoke can be taken off to keep things compact during travel.
Hi Alec,
great video again. Very educational as usual. :)
I can't help but feel that my comment (and the comments following mine) on your previous tank tech tip video (S03E04) sparked this episode. I didn't mean to start a "DIN is better than INT" discussion to be honest. Back then I just wanted to add some information that I found useful. After all I am still a diving newbie and just finished my basic diver (CMAS) certification and I greatful for all the knowledge you and other experienced divers share with us.
From what I've seen here in Germany steel tanks seem to be a cheaper here and more available than aluminium tanks, but I totally understand that you are in the northern parts of America and that aluminium tanks are much more common there and everywhere else in the world.
Since you mentioned a followup further down in the comments: One thing I would include in a followup video is the yoke adapter that can be fit on DIN regulators to make them compatible with INT valves / tanks.
Anyway keep up the good work, and keep those tech tips comming, I am really enjoying them.
Cheers!
Side note: DIN is the abbreviation for Deutsches Institut für Normung which translates to German Standardization Institute, which basically is the German equivalent of ANSI (American National Standards Institute).
I meant the regular steel tanks, not the ones with the increases pressure capability. The regular pressure steel tanks seem to be cheaper around my area.
Haha, I'm sorry that I made you do the video, Alec. ;)
I just received my first own tank. It's a 10l / 300 bar (4350 psi) steel tank and damn ... screwing in that long thread on my DIN regulator is a bit of a hassle. I haven't used a yoke myself yet, but whenever I see you snap one of those on one of your tanks I am like ... "damn that's quick".
Now that I think about it: I read that ideal gas laws don't really apply anymore for the higher pressure tanks. I haven't looked to much into the maths yet, but as a rule of thumb with 300 bar / 4350 psi tanks you have to calculate in a correction factor of 0.9.
So a 105 cuft tank will only hold 95 cuft when pressurized to 4350 psi. Please correct me if I am wrong about this.
I think this is something you need to be aware of before you plan your dives.
Cheers,
oB
Alec, thanks for checking on DIN weight/length as I was toying with the idea of converting my Yoke regulator I just bought to DIN since the tanks I use locally are HP steel that get filled with DIN and then have to screw the adapter on. I though it would be lighter/more compact for travel - but apparently NOT! - rest of the world are more likely to use Yoke anyway so I'm sticking to that! Always learning something with your video re-watching them and reading comments.
Thx Alec
Thank you for watching Wally.
Alec
Alec, it's okay to call someone an "Airhog".Thanks for sharing!
Mate you know your stuff
Ta anthony.
Thanks for watching.
Alec
Thank you
I love my black epoxy twin 45 steelies. Still prefer the short package. Time flies.
Thank you for the video. It is always nice to hear a sensible voice. Definitely, a steel cylinder needs more care.
I personally dive steel DINs but use an adapter abroad as required. The DIN fitting I find is less bulky which is useful with side mount configurations. It is also idiot proofing with regards to high pressure cylinders in that the 300bar DIN cylinders have 7 turn threads, whereas the 237bar DIN have 5 turns. A first stage DIN that is rated for 237bar has only 5 turns on the screw so when fitted to a 300bar cylinder will not seal and will leak loudly when turned on, whereas a 300bar regulator will still work on a 237bar cylinder (2 turns will remain exposed after the first stage is screwed in).
The Oring is the same size for both DIN and yoke which is very nice. DIN O rings are lost on removal or replacement of the first stage, but as you say, they are captured rings otherwise.
I would also add that a Faber 12.2L steel filled to working pressure (232bar) weighs a teeny little bit less that a Luxfer Ali80 filled to working pressure (3000psi), while holding more breathing air. That means I carry more air, for the same weight on my back, plus I get to lose about 2kg of lead from my belt. Win-win!
Thanks CK. All good points.
Right about the 200 vs 300 BAR fitting too. When pressures rose a few years ago (everything to me is a few years ago. It could have been 25 years ago but it's still a "few"), the 200 BAR fitting was upgraded and they wisely made the new 300 BAR fitting fit into the old 200 BAR valve but not vice versa. Mounting a 200 BAR fitting into a tank at 300 BAR would not have been good.
I still have trouble converting scuba tanks in liters to cubic feet so I'll take your word on that. Makes sense.
Thanks again for the info.
Alec
Here are the numbers in imperial if you want it (gas density 0.074887 lb/cu ft for dry air at 70°F, total weight not including cylinder valves)
Luxfer Aluminium 80
Working pressure 3000 psi
Internal volume 0.3920 cu ft
Volume of gas @ WP 81.14 cu ft
Weight of gas 6.09lb
Weight of cylinder 31.52lb
Total weight on land 37.61lb
Faber Steel 12L
Working Pressure 3365 psi
Internal volume 0.4308 cu ft
Volume of gas @ WP 99.95 cu ft
Weight of gas 7.51lb
Weight of cylinder 29.76lb
Total weight on land 37.27lb
I ran similar numbers below. the Faber 12.2L is really a 100cf tank - similar to the worthingtons HP100 I own. You should really be comparing a HP80 (faber 10L ?) to 80Cf alu standard... as you show it's slightly lighter on land, but holds 25% more air, but you're missing the bouyancy numbers! I found HP steel tank benefit to be a wooping 10lbs savings (land + lead around waist) vs Alu *of same air volume*. AND they don't lift up at the end...
I used a Faber 12 in the example because that’s what’s on the video and Alec mentioned that it was heavier than the Al80, which it’s not. Alec already mentioned the buoyancy benefits. A Faber 10L does store the same volume of air as an Al80 at working pressure
Does not ? above you have 12L WP = 99.95cf, so a 10L should be 83.29cf at same WP.
Alec made a mistake in his video say the steel tank was heavier (it's 25% bigger! even then not really but close). Have to compare apples to apples.
I was in the market for a used tank, and ended up going with High Pressure 100 steel, which happened to match the ones I had been renting all along). Here is something to consider. While ALU80 are cheap (about $170 online vs HP80 at $280) if you look at getting the higher capacity 100cf (I'm tall guy and like to stay as long as possible, not a problem with a drysuit even in cold 50deg waters in Monterrey) then ALU100 are much closer in price vs steel ($280 vs $330) but the worse part is the weight. Catalina 100cf is listed at 42lbs vs 34lbs for faber100 (whopping 8lbs heavier!) yet buoyancy is only -5.2lbs vs -8.41 full so you need an extra 3lbs of lead as well. That's 11lbs difference which is a lot to carry when I already have a belt with 26-30# and a full tank...
The difference between Catalina 80 (32#, -1.8) vs faber HP80 (28.6#, -8) is similar 3.4lbs heavier, yet 6.2# more of lead needed.
The tank I got (XS Scuba/Worthington X7-100) is ever better buoyancy listed at -10lbs full (I measure mine at -13.2lbs in pool water! and only 1.5# heavier on land than faber's HP listing). If I switched to standard CF80 ALU I calculated I would need to add 11 lbs of lead to my already 26# belt - Yike! :( (13.2 - 1.8 not taking into account salt water)
Most shop and people who knows dive HP steel here (cold water) for a reason. In tropics where you don't need much weight at all, ALU80 might be ok (not ALU100 running the numbers I did above!). ALU is HEAVIER due to thicker walls on land, yet not as high psi so more floaty (bigger water volume displacement) and actually FLOAT when near empty which you don't want diving IMO. The thing going for ALU80 is the price (and cool colors!), but that delta disappears in larger sizes (less common)...
fascinating video - no wonder ALU80 are cheap
ruclips.net/video/OmSvbp2NFbc/видео.html
I read one thing on a Google article that summed up DIN vs Yoke with a bit of interesting and possibly important nuance. It was talking specifically about travel diving - beyond the fact that DIN regs have a higher pressure rating which obviously appeals to tech divers and other adventure types which explore beyond basic rec diving and beyond the nuance of a captured O-ring vs a free O-ring, this article mentioned where the O-ring is.
In a yoke valve, the O-ring is on the tank... On a DIN valve, the O-ring is on the reg. That 100% sold me on buying a DIN reg, despite the extra cost. The article said that if you buy a DIN regulator, YOU own the O-ring, YOU are responsible for keeping it maintained and free of debris. Obviously, if you own the regulator AND the tank, you do whatever the hell works best for you, but specifically in regards to the topic of travel diving a lot or doing a lot of boat dives and resort dives where you spend the majority of your time renting tanks from a dive company, rather than supplying your own, it may be a bit of valuable piece of mind to know that this vital piece of equipment, the O-ring, is in your control and care, not the tank supplier.
Of course, it's *mostly* a moot point anyway because firstly failures aren't that common and secondly because yokes are so popular anyway that you'll almost always have the opportunity to dive yoke, but maybe not DIN, though very rarely will you have the opportunity to dive DIN, but not yoke, at least in the rec diving realm.
I guess as well it comes down to where you're diving in the world - some places are highly regulated and everything is strictly controlled... Some places are a bit... Meh, little bit on the edgy side. In those cases it would be a decent amount of piece of mind knowing that all you have to do is rely on a shop to provide you a tank that isn't corroded completely through and you'll handle the delicate stuff like your precious O-rings and stages.
In that sense, it's a shame that DIN isn't the standard, because I'd go so far personally as to buy a DIN reg and a yoke converter, in case I am put in a situation where I'm forced to use a yoke valve - in that respect carrying a small screw type connector, if you prefer yoke regs, and still having ownership and control over the O-ring is far more convenient than carrying a DIN converter to clamp onto a renta-tank with their God knows how well maintained O-ring.
I donno, maybe I just read far too deeply into it, but when I read that minor point in the article I read, it clicked for me in a weird way.
Having a captured O-Ring is a good thing. And, if you are a fastidious diver, owning and carrying your own tank O-Ring is good too.
Many divers are not and so rely on a good dive store to supply them with tanks and O-Rings.
I have no problem with DIN fittings and agree they have some advantages, as does the yoke fitting.
I DO have a problem with divers who claim the DIN is the ONLY way to go. Clearly, it is not.
Take care.
Alec
I have a "Steel 72" made in 1959. They used to use pipe threads to seal with Teflon tape.
More modern steel tanks use O-ring valves like aluminum 80's.
Aluminum 80's cannot be trusted after about 10 years old, some dive shops refuse to fill them since they can catastrophically fail from Sustained Load Cracking brittle fracture around the threads. The 6351 alloy also has age hardening over time which makes the alloy brittle.
Even the newer 6061 aluminum alloy tanks can be a "non-fill" after 10 years.
Aluminum tanks have a secondary eddy current test to look for cracks during hydro and some dive shops require it for annual inspections.
Steel tanks cost more, but they last longer. I have tanks made in the 70's/80's that will still pass hydro.
Yes, steel tanks can catastrophically fail as well but it's uncommon vs. aluminum 80's.
Rust (light haze) in a steel tank can be "tumbled" out and if the tank then passes hydro, it's good. Corrosion in an aluminum tank is an instant fail.
Rough estimate of strength: Aluminum is about 1/3 the density of steel, but it's also about 1/3 the strength so you need 3 times as much.
If you get a "boat fill" on a dive boat (some only fill to 1800--2000psi) the steel 72 holds more air that the aluminum 80 due to its larger internal volume.
In the 1980's there was a rash of failures on aluminum 80's due to the owners getting their tanks painted with a paint that had to be baked on at about 300--350 deg F. That was enough to soften the alloy and tanks were failing. Paint job looked fabulous, however.
interesting info. If your boat does low pressure fill, than LP steel are the way to go (a guy had a 120LP steel on my last trip and it looks like a water heater compared to my HP100!) but luckily they can fill to 3600psi but had them top mine off a few time after cooling off to get the full 3500psi my tank can take.
i enjoyed this video quite a bit i grew up in SouthFlorida and my first Scuba certification was in 1978 by a NASDS shop back in those days they weren’t as reckonized as PADI so i did get a PADI card in 1981 both were open Water certs in those days i always dove with plus Aluminum tanks to get the extra air i did also dive with many US Coast Guard Helicopter pilots that flew for Air Station Miami and a few of those guys still used Steel tanks and one even had a 2 stage regulator with the double hoses although it was getting harder for him to find shops that could or would work on them i have over 250 logged dives unde my belt and manu of those were in the Florida keys were we would drift dive using lines attached to a boat and the strong southerly current on the Gulf side it was a easy way to cover a lot of territory and by snorkeling in full gear if we spotted say a lobster or whatever we could easily pop in our regulator to extend our bottom time i was a avid Spearfisher then too using pole spears mostly although i had a couple of inexpensive manufactured Spear guns i bought at yard sales and fixed up to work back in my early days a dive shop owner told me that all the tanks either Aluminum or Steel were made in the same factory and the only difference in branding at the shops was the Valves the companies used ? now with my Coastie freinds they often had to fly down to Cuba for work and tanks their were very expensive we had a place in Hollywood florida that sold brand new US Diver Aluminum tanks for 99.50 dollars and when my plus tanks were getting close to not getting my 10%% anymore we would send them down to Cuba and sell them for just over a hundred bucks those military guys were happy and so was i as i just buy another brand new one btw you may remember the place as they always advertised in the back of all the dive magazines for years it was called Divers Unlimited and they always had a coupon for their 99.50 tank which you really didn’t need to bring in to the shop their logo had a bottle nose Dolphin jumping over a dive flag it was a brick and Mortar shop in my town and i’m pretty sure they shut down in the 1980s due to major road expansion and all the growth that South Florida went through back then i did get married and moved away to raise my family and occasionally visit yet unfortunately experienced a Major Stroke in my 40s and was fitted with a new Aorta Valve that i wont be able to Scuba dive ever again according to my doctors ? although i’m hopeful that with modern medicine that may change as ive owned 16or 17 boats in my life so far and love Cruising the Bahamas and other parts of the Carribean so we will see i’m okay with Snorkeling if i have too at the moment i’m on quarantine with most of the world due to Covid 19 so i wish you a safe future and look foward to more videos
Thank you very much Craig for sharing the memories of our 'stone age' diving. Looking forward to everyone being able to return to diving with new stories to share.
Alec
Hey Craig. I got PADI certified in 1977 at Broward Community College in Ft. Lauderdale. Used to go down to the keys and beach dive off Hollywood Beach. Lived there for years. When I joined the Navy in 1985, I sold my scuba gear. Now, I just obtained a copy of my PADI card and am getting back into diving at 63 years old. Planning on taking a refresher course. The adventure continues...
Richard Jurewicz yes thats where i got my Padi certification did my open water dive on joe Shircks boat he was a Boward Shettiff Officer at the time and ran trips for a dive shop on US1 inFort auderdale i may have his name spelled wrong and i do not remember that shops name other than it was North of 17th Street Causeway on the Eastern side of route 1 my apologies on typos my key board is acting funny with caps and some symbols who did you know at Air Station Miami ??? William Perrin was one of my parents best freinds he retired out of headquarters eventually as a Captain Dennis Seahouse was another pilot i knew along with Mike Quinn all those guys taught me a hell of a lot about diving and becoming a man when i was in high school i worked in a east food joint frying Chicken and we were able to take home any leftovers so i brought cold chicken on our dives and those guys all called my Chicken little as i would carry out big bags of chicken from the house when they picked me up to go diving Perrin did instruct Helo pilots up in Pensacola for 4 years and later worked out of Washington, d.c. when i lived in Maryland at the same time so he and i continued our love for the water and the outdoors doing boating and Camping plus we did a lot of Hiking on the Appalachain trail that was only a hour or so from our homes btw his given name is William but he goes by his middle which is Randy really Randal very smart man worldly and Educationally as luck would have it he has a son that is close to my age and him and I are still very close like traditional Cousins would be the family roots are louisianna and thats where they reside now ironically when i did the class at BCC my best freind was giving me some slack about not swimming fast in the pool and i had to tell him why it was simple there were all these hot girls in Bikinis And i picked the slower ones to swim behind their fins and my buddy was like ohhh thats a good idea i’m like Duh i could do circles around her but why would i ? i’m like how could you not see that he always was a little naive around the ladies lol in his defense he has most of the money and things he bought over the years and ive gone through several houses and bank accounts that went to exes f
Alec I’m so glad I stumbled across you channel. I’ve learned so much from you. I will be purchasing my own tanks soon and would like to know what size do you recommend. I know the aluminum 80 is the standard, but if I dive with Nitrox wouldn’t a steel 133 be better? What are the pros and cons to larger tank sizes? Thank you for the expert advice in advance.
For regular diving, that is, not extreme deep, cave or wreck penetration, the aluminum 80 is still the best bet, even for Nitrox. It's cheaper, easier to maintain and perfectly balanced for recreational diving.
Using Nitrox does not affect the tank choice. In all likelihood a Nitrox dive is shallower and maybe even shorter than an air dive. The idea that you need a 'big, high pressure' tank for Nitrox is another of those mistaken attitudes from technical diving that have permeated the recreational diving world.
Get an 80 and go have fun. Take a Nitrox course and then you can decide if it's for you and if you want to get a different tank.
Good luck.
Alec
Ripper Tech Tip.
Could you please consider a 300 Bar versus 232 Bar Cylinder comparison and Twin verses Single Cylinders?
I'd love to hear your perspective and overview.
Please show the home made tanks and regs.... Gotta see this.
Great info, Alec. Thank you. What are your thoughts on the effects of sunlight exposure in regards to the life of the tank, when using aluminum or steel? I often dive from a jet ski, and the tank (along with the rest of my gear) is always sitting in sunlight all the way to and from the dive site. Assuming they’re both taken care of well with the same level of maintenance, will steel tanks have a longer lifespan in these conditions? Or no difference at all?
Far as I know, the sun has no effect on tanks. It may fade the paint but that's about it.
In most warmer dive locations, tanks will sit all day, every day in the sun.
Alec
Your hoses and neoprene will suffer far more from direct sunlight than the tanks. Especially hoses should not be kept in the sun.
educational to be sure.
The more you watch the bigger you IQ gets!!
Thanks for the great video Alec, You mention the new steel Faber to be heavier than the Catalina Alloy 80L?
I have a faber 12.2l (100 Cubic feet) and Also a current Catalina (80Cubic feet). Both have the same valves, on the scales The Alloy Catalina weighs 14.3kg and the Steel Faber(232bar) weighs 13.2kg.
+madrx2 are those full weights or empty weights? Alec is correct about divers choosing one tank material over the other for the negative bouyancy but what he did not mention is that it is at the end of the dive where this is most relevant. The heavier tank of the same volume is less buoyant when closer to empty...this allows a diver to dive with less weight on their belt/in their BC while not bobbing to the surface like a cork from their safety stop depth at the end of a dive.
***** Yep, the density of the steel makes them more negatively buoyent. It all makes sense to me now . Thanks Alec!
Well I heard you talked about in an earlier video of yours. My buddy an I bought a steel tank back in 1963 an watched Sea Hunt and went diving and we are still here. But that was the good old days.
What I would like to know is, I bought a US Divers Aluminum Professional tank back in 1974. DOT-SP6498-3000, P21480, 11 ^ 73 USD. Now a lot of shops won't fill it and the others I have to have it tested before they will fill it. When I got a hold Luxfer Tanks about the Life Time Warranty they said the tanks good so screw you. It gets to cost a little much every time I have to fill it. Is that the way it is now! Thanks Alec, Joe the vintage diver
Wow! You have started a real debate here Joe. So many topics in one short comment!!
Let me share some ideas, most of which you'll find confirmed if you look around.
1. It's probably easier to get the old steel 72's from the 60's and 70's tested and made useable than it is for the Luxfer 80's The reason for the problem with the Luxfer tanks made between 1972 and 1988 (in the US) is the aluminum alloy used (called 6351) which is subject to SLC (Sustained Load Cracking), a potentially dangerous problem.
2. Proper annual inspection will determine if your tanks are suffering from this problem. It is a slow process so the annual inspection is sufficient to keep you safe. Note that SLCs are uncovered by a visual inspection- NOT a hydro test. The tank may well pass the 5 year Hydro Test but fail visual.
3. Proper storage of scuba tanks is helpful too. As I've explained in my videos, your tanks should be stored with some air in them BUT NOT FULL. I suggest less than 500 psi. This is long-term storage - 6 months +.
4. The LifeTime Warranty is long over. I know that sound silly but life is usually determined to be 15 years. It's academic at this point since U.S. Divers has changed hands several times since the 70's and the current company has no liability for an old warranty.
5. Luxfer did offer an exchange program for these tanks (US only) but that's also long over. Don't feel too bad about that since the cost of shipping your tank to Luxfer for their "assessment" would have purchased a new tank!
6. Because of some well-publicised explosions (very few), many dive stores simply avoid the problem by refusing to test or fill the old Luxfers. That's their individual, business choice and they have that right just as they can choose to not sell you a mask! In their defense, the tank explosions have almost invariably occurred during the filling process, not on the diver's back.
7. Because of inconsistency in Visual Inspection methods, a dive store may not accept an inspection sticker from a another store and can require you to have another inspection before they fill the tank. Again that's their right. Again in their defense, there are lots of divers out there who have taken an inspection course and have Visual stickers for tanks but who do NOT necessarily do a good job, particularly when they have are not in the scuba business so have little to lose if their methods are sloppy. Heck, you can buy Vis Stickers on eBay!!!
8. As an aside but interesting, you will notice that your tank is so old that it was produced under the Special Permit (SP6498) from the DOT before aluminum tanks were finally recognized as safe and received full certification without the SP designation that had to be renewed regularly.
9. Another interesting aside is that your tank is a "Professional" model from US Divers. All of their tanks were identical production (other than the color of the paint) but they would put different banners on them - MKI, MKII or Professional. Dive stores simply charged more for the Professional model. Same tank; different color and banner!
10. Not to question your story, but Luxfer would not say "the tank is good" without seeing it. They may have meant that the tank is good if inspected and passed in which case you start reading this reply from the top again.
Many dive stores (like my old store Scuba 2000) will give you a Trade-In on your old Luxfer tank which will make the purchase of a new tank so reasonable that after 2 years without tests and aggravation, it's pretty much free.
It's irritating but I suggest you think about the fact that you have made hundreds (maybe thousands) of dives on that good ol' Luxfer. Maybe it's time to retire it. Is there anything else that you own that you have used for over 40 years under extreme conditions (marine environment and high pressure) that you still use today? (wives don't count!!).
Good luck. Thanks for watching. Alec
Alec thanks a lot, I left a comment on your video on vintage knives. Everything I have is vintage, but I did have to get some new stuff. I had to send my U.S. Divers Calypso regulator to vintage repair in Washington State a few years back. My wet suits, masks, fins and BC's rotted away over the years. Still have my weight belt with new webbing and 25 lbs. of weight. I guess I'm just an Old Geezer but I'm still kicking. I have been watching everyone of your Video's and they are GREAT! I wish your shop was around here! I really hate to get rid of my tank with all Dates and all the different Stickers on over the years. Thanks Again, Joe The Old Vintage Diver.
P.S. I bought my tank at where Ikelites were made back than in Indianapolis, IN. there was a Dive Shop in front. Now I live in Glendale, Arizona.
I know that shop. It was owned by Ike, the chap who made the first decent underwater lights. They became famous and were known as Ike's Lights - now called Ikelite. Neat huh?
Yeah, I liked my old tank with the hundreds of stickers too. You'll be shocked to know that all those old stickers are supposed to be taken off during a proper visual examination - any old visual stickers anyway.
Maybe you should put your tank on display in the rec room or garage where your grandkids can see it and ask about it.
Take care. Alec
oh no, I found some ALU 50s to play around the pool/kids but they are Luxfer 3AL3000 from 1984 (dacor) so assuming they have the same problem ?
CTC/DOT 3AL3000 S50
R7222 / R7233 LUXFER 1 A 84
last hydro (?) was 9/16 VE (is that visual only ?)
Hi Alec! thanks for a very informative video! I am looking into buying myself the Luxfer AL 80 tank for my diving. Would you recommend this? Or are there better aluminum alternatives? Regards, Chase
Chase Kaplan Dive Gear Express also has a good read on this. One thing to note is recent tariffs have made aluminum more expensive than steel and some shops may not refill aluminum tanks beyond a certain age. I'd recommend getting a bigger tank and underfilling if you can handle the weight as it is less stressful.
DIN also ha less potential points of failure. Also with yoke you run through O-rings like it’s nobody’s business. When I use to work in the industry. I always had a pack of new O-rings for yoke valves with me. I went to maybe four to five packs per season. With DIN I had maybe six to ten O-ring changes per season.
This will be a never ending discussion just like which is the best fin, dive computer, BC etc. If your comfortable with a particular setup, have fun diving.
Note there is a difference in DIN valves in tanks also. 5 thread are use up to 3500PSI/232/bar, 7 thread for use with 300bar (4500 PSI) tanks. A 7 thread valve also has a deeper drilling inside the 'O' ring face. Most charging whips are 7 thread but those on a 300 bar compressor also have a small extension inside the 'O' face to stop them sealing onto and charging a lower pressure tank.
Similarly DV's rated at 3500 PSI max have only 5 threads so when attached to a 300Bar/4500PSI will not seal.
You are correct but this was a basic intro for those who need to know the differences. Your points are much appreciated.
I still have my first tank from 1973, a US Divers Mark 1, which is an aluminum 80 rated for 3000 PSI. It is the same brand of tank that was in the first Jaws movie and exploded the shark. I think this was the first available aluminum 80. No shop will fill it anymore because of it's age. (so I fill it myself to 2000 PSI) Now I prefer 100 cubic foot high pressure steel tanks.
The exploding tank in Jaws was pure theatre wasn't it! Do be careful filling any tank to ensure it gets a hydro every 5 years and annual visual. I have a Tech Tip on tank inspections coming up in about 3 weeks you will find helpful.
Thanks for watching.
Alec
Myth Busters TV show did an episode involving scuba tanks getting shot with a rifle. The result was not like the Jaws movie. It was more like what happens when you let go of an inflated rubber balloon. Yet I've read stories and seen pictures about what happens when an old aluminum tank fails while being filled. So have all the dive shops which is why they won't fill old aluminum tanks from the seventies. I find your videos to be very informative even though I'm not a novice diver.
I saw that Myth Busters too. my buddy was diving his 80/100cf alu until I showed him my 100HP tank which are lighter and slightly smaller than even 80 alu outside volume. Sold all his alu tanks and went HP steel.... the only ones we kept are the 50cf alu from the 80s for the pool and kids - quite light even for 1/2 the capacity.
Alec, have you ever come across titanium tanks? I worked for a guy who owned three which I used to dive. No markings on the tanks, supposedly they are from Europe and there are less than 20 in the world. Would love to see a video on this if you can find one!
That's a new one to me SSP.
I suppose they are very light, and strong too.
Also Titanium is resistant to corrosion (it forms a protective oxide layer on exposure to air that protects the metal underneath just like aluminum) from air or water, whether fresh or salt, even to acids
But they'd be expensive for sure. Maybe a titanium-coated tank would be cheaper.
Many "titanium" products are really just titanium coated. I mentioned in another video for divers to watch out for "titanium" products like dive knives and regulators that are not really made from titanium. Some products labelled titanium are just painted a titanium color! Totally useless!
And then a diver needs to consider the buoyancy of the tank. It took quite a while before manufacturers found the right combination of weight and size for aluminum tanks so they'd not be too buoyant to use.
Neat idea though.
Thanks.
Alec
Hi . how to choose between 200 bar and 300 bar . I m using a DIN valve and it is working at 300 bar . I m doing a lot of deep diving and I am thinking to buy a new tank (300 bar ) . or can you make another episode about this problem ?! Please ! Thank you for everything and for the Sea Hunt series . You ( and Kevin ) are making a fantastic job . Thank you verry much for everything .
Laurentiu Charec the 300 bar DIN valves have more threads. If you noticed when you screw your regulator into a "standard" (200 bar) DIN tank, some threads are still exposed. The 300 bar captures all of these to make it more resilient at high pressure and added security of the captured o-ring. An advantage of the 200 bar DIN valves is you can screw in a double o-ring insert to convert them to accommodate a yoke regulator. With a 300 bar valve you can't do that, too many threads, a yoke regulator won't seal unless you get a special kind I guess but I've never seen before. Given the option, a 200 bar DIN is adequate for most uses. The only 300 bar DIN valves I own are on my backmounted doubles, even my stage bottles are 200 bar.
Tanks a lot! 🦈
Welcome!
@@AlecPeirceScuba_SeaHunter r/whoosh
Din has a higher max pressure and is more compact. It is objectively superior but everyone uses yoke here
The DIN connectors are pretty much everywhere outside North America, it does not necessarily make is superior unless in the eyes of the user. Both yoke and DIN meet the needs of divers in their geography and work well as designed. DIN has a higher maximum pressure because of its design, yokes work perfect for 3000 psi, 210 bar because that is their design limit. Everyone has their view and preferences, I'm showing options and information some new divers have never been exposed too. Enjoy your DIN's my friend.
I used an aluminum 63 when I took my training course in the pool
Good choice. We used the same tank in our training center - lots of air and much more convenient.
Alec
Hello Alec, I'm in the beginning stages of Tech Dive training and am trying to choose tanks for doubles. I know I want steel for the weight I'm just not sure of Low Pressure vs. High Pressure and what size would be best. Can you elaborate on the differences between LP/HP and volume?
There are lots of factors to decide between the two, kind of like saying are blonds or red heads better? I won't write a thesis but hit on a few major points now. Try searching or posting on www.scubaboard.com for help from the dive community.
HP's are shorter than the LP, it puts its weight higher toward your head but have excellent weight to volume ratios. Getting good fills may be a problem as not all LDS can fill HP's (easy to fill to 3000 psi but harder to hit 3500). Your reg must be compatible with HP and use a 300 DIN adaptor to operate at a working pressure of 4350 psi. No yokes used with HP's. You need to decide which buoyancy properties are best for your diving. Only a few points to get you started but keep researching and if in doubt, ask you LDS or a buddy to try each to see how it feels. Take care Blake.
Don't be so sure on what you said in the beginning I started diving when i was 9 (2009) and i mostly use steel 72 hahahaahahahah yes I do use some 80s I admit that. But i also use a neoprene wetsuit from the late 80s and have big long dive knife (10in) from the 70s. Some of us haven't found the new way just yet
I loved the old steel 72s. But, they are gone or almost other than for vintage divers.
When I started diving in the late 50's, if you didn't have a 10"+ knife you weren't really a diver!
Take care. Alec
Are there differences with hydro dates for steel vs aluminum? My aviation background we had different hydros for composite O2 and N2 cylinders vs steel.
In North America, steel and aluminum are 5 years with no consideration for the tank material.
Sir Alec,I've got one question.Seen a lot of ur videos and really appreciate...I just wanna know is it safe to dive with Carbon Fiber tanks?Seen people only talks about steel and alluminium🤔
Carbon fiber tanks are not that new, just improved over the last years. Primarily as staging, bailout or spare air bottles the major drawback of these are they are un-inspectable and easily damaged. Best to check with actual users on www.scubaboard.com to get their ideas.
carbon fiber tanks will only last 15 years and hold 4500 PSI, steel tanks last 50 years and go to normally 3000 or 3500 PSI. get a steel tank
Steel tanks 12 LTS is the best opcion vs 80 Al. tanks More air. less weight on you belt and you pay the same price like Al if you Rent the tanks. If You dive with steel tanks you never come back to Al.tanks,......well maybe the sidemount divers for others reaasons. Nice video
Thanks for sharing Manuel.
Hi Alec, any suggestions on how to receive training and certifications in gear maintenance? Is there a basic cert that covers most equipment types?
Unfortunately, each manufacturer has their own 'authorized' service course. Regulators are very similar but still not the same in tools, assembly and lube points. Suggest picking 2 that are very popular on your local dive shop so you get lots of practice. Then add others based on the type of gear customers bring in. No sense being certified on a brand that shows up 1 every 2 years. Talk to your LDS and speak to their service pro on which are popular and can they arrange courses. Hope this helps Maggi.
Alec
Amen to that, more muscle than brains lol. Nice to think about the old days!
I have been diving with aluminium tanks for many years, but I still miss a lot my old 18 Lt 220/330 Bar steel tank. It contained 3,960 Lt (140 cubic feet) of air and did not change (much) its buoyancy during the dives.
You must have a strong back my friend. I knew a diver who used a big steel tank for 2 dives before filing it. Kevin dives steel 100's at home and I take whatever tank they give me.
A
@@AlecPeirceScuba_SeaHunter :-) I admit, I was much younger… 30 years younger :-)
@@GuidoCandianiWhat youre age my young friend
@@user-xh8bf6rd6s 58 and have been diving since 1984 :-)
I started with the steel 72 cu ft & used them for years. Mid 80's I got my first AL 80. Another 5 years & i was back to steel, but a 90. Now I'm back to AL, but a 100. I wear a 3x 5mm farmer John & 7mm thigh length jacket for a wetsuit. Yeah, the extra tank weight is nice. 🦈
Very cool!
A.
I'm curious about the new batch of neutrally buoyant (when empty) aluminum tanks. They run about the same price as steel, 300 street. Is there a video on them and would it affect your recommendations? I'm guessing the better resistance to rust gives peace of mind for saltwater divers.
They are nice to remove lead but it now the extra weight is entered on your back, not on the belt or integrated pockets. Other than buoyancy, the other factors remain like overall size (bigger than steel), max pressure 3,300 vs 3442 for steel, service etc. See if your local dive shop will let you test one in a pool or lake to see how it affects your trim and comfort before buying.
@@AlecPeirceScuba_SeaHunter Thanks for the prompt response! I talked to a scuba forum and they mention there's also balance (relative to steel) to consider. Definitely will try them out at my LDS.
Never mind the extra pressure available, probably you are not going to need that. However, there are other reasons the DIN excels over yoke the main one being that you are most unlikely to have an O-ring problem, actually, I’ve yet to see anyone have a problem.
The O-Ring on a DIN fitting is located on the regulator, not the tank valve.
That fact alone saves the O-Ring from some of the abuse that a regular (yoke-style) valve & O-Ring go through.
However, the O-Ring on a DIN must still be inspected and replaced regularly.
And it ought to be protected with a DIN cap while not in use.
I HAVE seen them fail and fall out.
If a yoke valve O-Ring is inspected and replaced regularly (all of $1.00!) and one uses a valve cap for protection, the yoke-style O-Ring is just as reliable. It's also less expensive and it's quicker and easier to mount.
A lot of my viewers are from the UK or Europe where the DIN is standard and lots of my viewers are into tech diving where the DIN is more popular but please don't sell the yoke short. It's been giving great service to divers for a heck of a long time and there's no sign of it disappearing.
Thanks for watching.
Alec
I just bought a scuba compressor ...se add led packaged filters Came with it but they are about 13 years old... I ordered new ones but I’m tempted to to fill and try out my new compressor using the ones that came with it... is this a high risk?
Breathing air must be clean and pure and the only way to be sure, regardless of manufacturer claims, is to have a sample sent off for testing. Don't risk a problem by skipping this test for yourself and anyone you fill. Most compressors need maintenance (annual and by # of hours) for proper operation. After 13 years be suspect until tested.
alec I have 2 older steel tanks that have certainly been completely empty for a few years. my question is. if they have some rust inside can they be cleaned and re certified ?
Well, it's not good that they've been completely empty but they may survive. Have your LDS (local dive store) do a quick visual check to see if they're OK. Then get a hydro test and proper visual. If they pass, they're good to go. I suggest the quick visual first to see if they should even go to hydro. If there's signs of serious rust because of moisture or even high humidity, there's no point spending money on a hydro. Most older steel tanks show some rust. It's called surface rust and is not a problem if it isn't corroded into the steel and isn't loose. They can do a quick clean with a special brush or if needed, tumble the tanks to scour the inside. Even then they will likely get a thin rusty finish on the inside but that's not a problem. When a tank is hydro tested, it's filled with water and unless it can be dried instantly (almost impossible) it will develop surface rust. We use a rust inhibitor in the final rinse and very hot water and an air dryer but some rust is inevitable. Hopefully they are not too bad and can be saved. I don't need to tell you that you must keep some presssure in them at all times. Just 100psi is enough. You also need to consider the cost. An older steel 72, tested and ready to go, is worth about $100. A hydro and visual will cost you about $50 or $60 so be sure the tanks are worth saving before you start spending money. Good luck. Alec
I have been considering a 95 Low Pressure Steel tank against a 117 High Pressure. I like the size and weight of both. The size is almost identical in both. The 117 weighs 5.4lbs heavier, but the 95 is more of a floater when empty, so you need to wear more weights to compensate. Before jumping in the water the diver will be about 4 lbs heavier with the 117
I believe the capacity ratings for the low pressure tanks is based on their + rating. So after 5 years, the 95 tank becomes an 86.4 tank. The pressure is reduced by the 10% the + rating allows. To find how that effects volume, I took 95 / 2640 x 2400 = 86.363. Rated capacity divided by the pressure it is rated at, gives a volume measurement per psi, then multiplied by the new pressure rating. Is this correct? If you take 10% from 95 you get even less, 95 - 9.5 = 85.5
The high pressure tanks do not have a + rating, so their capacity stays the same. So after 5 years, the 117 holds 30.6 more cu' of air, is about the same size and only weighs 4 lb more. Am I over looking something?
If your not sure which to pick, your comment may have been cut off, ask the dive store to let your take them for a test dive. They may have a rental of each and see how they perform with your diving style. If a good dive shop, this should not be a problem. They want you to return for fills, VIS and hydro tests, club events, trips, etc. Take care.
@@AlecPeirceScuba_SeaHunterThanks for the replies. I was wondering if my logic for calculating actual tank capacity was correct. ( rated capacity divided by rated pressure multiplied by the actual pressure).
I did buy the 117 from a local shop yesterday. (3rd Reef in Las Vegas. Real nice guy by the way). It weighs a bit more than aluminum 80, but holds 50% more air. 117-77 = 40.
The aluminum 100 weighs 42lb. About the same as a steel 133. And it is 2lb buoyant, so may need extra weights.
These tips are so great. I have a question, feel ignorant. I usually come back with plenty of air when buddies are low. I thought
Why should I have to bear the weight of the heavy tanks (getting hard on the knees). So I bought a 30 cubic foot tank, thinking
it would have less PSI. I walked from my car to the water and it was so nice and light and not cumbersome. Just going for a swim to check buoyancy with this tank and to my surprise it has 3000psi. How did that happen?
OK Head clearer now. 30 cubic feet is measurement of volume of air
at surface and is compressed to 3000psi just like a higher volume would be. So I have less than 1/2 the air that would be in an 80 cubic foot tank.. What threw me off was that when I went in the water to check buoyancy with this tank, I was under water 20 minutes and only at 2000 psi. I think this will be fine for my shallow offshore dives, maybe even shallow water boat dives in the area. In nature I like to be still
and let things come to me. I like to hover in the water. Most trips with
others are constant swimming, swimming, swimming. Everyone always seems to be in a hurry.
Right you are.
The North American measurement system is more practical. It tells you how much air you have available to breathe rather than telling you the size of the tank.
Since you use about 1 cubic foot of air per minute at the surface, an 80 cubic foot tank will last about 80 minutes. As you descend you use more air per minute so the supply doesn't last as long. But as you've discovered, the air pressure in the tank is the same - 3000psi. Just the size of the tank changes.
What's been your experience with those no-name Chinese made aluminum tanks that have been making their way here in Canada? Are they safe and will dive shops fill them?
Didn't know they were here. When I owned my dive stores only USA made tanks were sold. Never a problem with then to sell, service, VIP or hydro. I'll take a look at these but if foreign tanks are allowed in, they must meet all the same tech and certifications as any tank.
DIN v INT (Yolk) OK let's get round the Imperial /metric difference. A DIN regulator is rated at 230 Bar, an INT (Yolk) regulator is rated at 200 bar so can maintain less pressure. In some places in the world, they inflate tanks to 230Bar, that's what they do. I first encountered this in Gibraltar. My Second stage was fusing all the time at the start of thye dive. I had to get out my tool kit and fixed my regulator to cope with that. YES I am a very bad man I'm not supposed to do that. Things got worse, in Egypt (yes that's the red sea) they are set up to dive DIN. The tanks are inflated to 239 , DIN connection but they offer adaptors for INT. Now on the DIN connection YOU maintain the O ring. With an INT connection the boat maintains the O ring OR doesn't maintain the O Ring. The net result on a dive at 5 metres on INT the O-ring failed. Do you know the noise that makes behind your head? After that I bought new DIN regulators and put my favorite INT regulators in the loft. True story, if you travel to dive, get DIN, or rent local.
Thanks for sharing your experiences. Actually I do know what it sounds like for a reg yoke to fail!
A
i have old conshelf supreme yoke style it is stamped 4000psi can i use this over the3500 psi.
4000psi is the maximum pressure allowed.
Most are now 4500 or 5000 psi.
However, I'd not be worried about it.
Those old USD yokes were stroooong!!
Alec
I only dive with steel tanks with a DIN regulator. Aluminum tanks are way too buoyant for my taste. (plus they usually can hold up to 200BAR s, whereas the steel ones are usually 232 bar or even 300.) Of course, all this is a matter of personal preference. What is of great importance however is the maintenance of your tanks, and making sure that they are given to a professional for a hydrostatic test, or for visual inspection. In Europe, a visual inspection should be conducted once a year, and the hydrostatic (depending on manufacturer's specifications) every 3 or 5 years.
same in the US (1 year viz, 5y hydro). Wish HP steel were more common here (what I also use, but yoke as DIN are harder to find deals on) and closer in price to ALU (which they are in Europe I understand). They are much more efficient (lighter yet better buoyancy - how about that!)
Hmm, here all tanks (or most of them as far as I know) are DIN but they all come with a yoke adapter which you just have to screw on and you're all set, in case you have a yoke regulator. No need to carry around an adapter.
Strange that the price of steel tanks are so much more than aluminium. In the UK steel tanks are cheaper than aluminium tanks and preferred due to their bouyancy characteristics. Maybe this is due to the majority of UK divers wearing drysuits due to water temperatures
Aluminum tanks are the most common in North America probably because there is lots of it available and so is very cheap.
I need a tech tip ... My Nikonos 4A has a bad battery holder and I need to know how to replace it and where I can get parts for my Nikonos 4A ...
There are stores that cater to Nikonos camera fans. The best place is probably eBay. You can get a complete Nikonos iv body for $30. You could use it to practice getting the battery compartment out and then install it in yours. Full service manuals are also available. Good luck. Alec
Alec i just bought a 300 bar (approx 4300 psi) regulator (aqualung legend elite) and am considering buying a steel 100 high pressure tank which apparently are only good up to 3442 psi per your vide. Are there 300 bar (4300 psi) steel 100’s out there or are they strictly special order items?
For scuba diving, high pressure steel tanks max out at 3442 for a variety of reasons: hard to fill tanks that high, max limit for yokes and the industry not wanting to sell & support higher limits (liability!!!). A 100 cu/ft steel tank filled to 3442 is a LOT of air for recreation diving. Techies just add more tanks for long time OR go rebreather. As good as the Aqualung is rated for, you don't want to be at the max depth when diving.
@@AlecPeirceScuba_SeaHunter thanks Alec. I’m a gas hog and was just curious if there was an alternative to doubles as my old legs can’t handle that much weight. John
It's 6:30 in the morning and the clock behind you says 9:35.Are you sure it's 6:30? ;)
That's Hollywood!!
OK. So some of my stories are embellished. Still sounds good right?
Truthfully I was giving Kevin a hard time. We were supposed to meet early but, he lives over an hour away and got caught in traffic.
Thanks for watching - so closely!
Alec
you mentioned the yoke is made of steel along with the DIN fitting , most regulator and valve parts are made of plated brass
You're quite right right Ralph. All valves, whether yoke, doubles or triples are made of brass, usually chrome plated although some have a flat finish and some have a 'titanium' finish (not really Titanium). Unfortunately, many of the threaded parts, nuts, couplers, etc. are made of steel so it's very common for divers to overtighten things in a mistaken effort to make sure they don't leak and strip the threads. A good example is the port plugs or the hose ends. The real irritation here is that the port plugs doesn't strip - it's steel. The body of the regulator strips! Thanks for watching and catching that slip. Alec
Alec Peirce Scuba all? how about those fancy Atomic titanium regs...
Yup some regs are titanium , not suitable for oxygen service , I wouldn't use them for nitrox either unless you exclusively do dive travel and weight is a big issue for you good old brass regs are a better option as brass is less brittle brass also gives far superior cold water performance having a thermal conductivity of around 110 watts per meter per Kelvin where as titanium is around 20.
Pretty huh? In my opinion, for titanium regs that's what you're buying - looks.
Contrary to what an Atomic fan will tell you, which he undoubtedly heard from an Atomic salesperson, and as Ralph has pointed out, titanium has one single advantage - weight. It's lighter than other metals used in regs. But you pay a lot of money for that small weight saving. Realize that you're talking only about the first stage body. All the rest of the regulator is the same as all others on the market.
And, again has Ralph has mentioned, there are actually some disadvantages to titanium. It isn't just the lower thermal capacity of titanium, it's the smaller mass. I used an old (1975) DACOR 400 for many years and it was the best I ever used under the ice. It was so big, solid and brass that it took forever to cool enough for the moisture in the air to freeze. Not the best for travel maybe but great for diving in cold water.
Thank you for sharing your wealth of knowledge. When I began diving the all titanium regulators looked like a big advantage with their superior resistance to corrosion. As I later learned about using 50-100% O2 for deco titanium all of a sudden became a pretty metal that may spontaneously burn...not so good. They are kind of like an exotic sports car, shiny, expensive, and not so practical. Love your videos!
Looked after i believe steel tanks will last longer. I have 4 x Faber 12l (100's) that are 25 years old, 2 120's and 4 x7l sling tanks also Faber that are 20 years and have been hydro-statically tested ever year ( i'm an Aussie ) they show little rust issues and i live in a tropical climate. Aluminium on the other hand fatigues particularly around the thread ( micro cracks ) and suffer stretch under testing causing failure . My mate is a hydro- static tester and was almost killed by a valve tearing out of a aluminium tank under testing it shot out of the tank as it flung on the whip and embedded itself in the wall narrowly missing the side of his head by inches.. ( dont mess with compressed air it's very dangerous stuff ) Not an Aluminium tank fan at all
I'm pretty sure you're right Ian. The big "if" is "looked after".
Scuba divers are notorious for NOT taking good care of their gear and that certainly includes tanks. In fact, tanks are probably the most neglected piece of scuba gear.
With care, a steel tank will last forever. I have some from the 1950s that are like new. The newer ones, like your Faber, are better.
However, an aluminum tank will withstand the abuse that most scuba tanks suffer better than a steel tank.
BTW, neck cracks are pretty much non-existent now. A valve that bursts out of a tank is a sign of neglect. The tank threads were not inspected.
Thanks for watching and for your comments.
Alec
HI Alec! Thank you for the great videos. I have a question about steel vs Aluminum. Do you find the balance to be different? I feel like the steel wants to turn me over on my back. I only dive aluminum once, and i don't remember that feeling. (new diver in New Hampshire) Thanks!
You're right! There's a big buoyancy difference. Steel tanks are decidely negative while aluminum tanks are slghtly positive when empty and only slightly negative when full. So with an aluminum tank on your back and with weights as usual close to the front of your body and in the normal attitude for recreational divers (horizontal facing down) your balance is nearly perfect. Put on a steel tank and now your back wants to swap with your front - you roll.
Using a steel tank requires you to move the weights around until you find the rght positioning of them. Once that's done, and it can take a bit of time, you'll be fine again. Steel tanks are the choice among technical divers (cave divers and for wreck penetration or deep dives) who want less lead weight but a negative positioning. They tend to be close to the bottom, want minimum fin movement and more controlled buoyancy without excessive use of a BCD. None of these is as important to recreational divers so the use of steel tanks and their odd characteristics is avoided, unless you're just looking for more capacity. The aluminum 80 tank, universally the preferred tank worldwide, is so for a reason. It is a near perfect combination of capacity, weight, size and buoyancy for most divers. That didn't happen by chance. It was designed to be so. The first aluminum tanks (1975?) were different. They were 72 cubic feet, longer and smaller diameter - 6.75 " versus 7.25". We called them torpedo tanks. Not many exist today. I have a couple in my collection. They were made that way to compete with the old 72 cf steel tanks that reigned supreme for 40 years. They were even the same pressure (2400psi) as the old steel tanks. Tank manufacturers wanted divers to accept them as a good substitute for their old steel ones. As the aluminum tank became more accepted by divers, they changed the size and pressure to what we have today. Good luck with your tanks. Thanks for watching. Alec
Thank Alec! I enjoy your videos!
Thanks for watching Bruce. Alec
If you want to start a argument inside of a dive shop ask someone which is better steel or aluminum. Everybody has their own opinion. I personally only use aluminum. It doesn't matter if I'm wearing my heavy wetsuit or even my dry suit I dial in my buoyancy.
Then you have the whole argument about should you buy your own tanks or just rent them. Even before I was certified I owned all my own equipment. Every week as I was getting certified I would buy what I needed and by the time we went to the quarry I have owned all my own stuff. Same thing with the scuba tanks. I'm not saying that when you travel that you would get a bad tank with bad o-rings but why take the chance.
I will tell you that after your discussion on the steel tank I might actually get one and trying out this year. I like the fact of the more air seeing that the older I get the faster my tank goes dry.
Divers have strong opinions and will argue over anything, fins, tanks, yoke vs DIN. They mostly confuse facts with personal preference and geographical preferences. I give the facts and let others argue nonsense. Keep an open mind and question everything until your satisfied with the answers.
Alec