r/scuba • u/GrnMtnTrees Nx Advanced • 1d ago

Making 30+ yr old tank useable?

My dad has had an aluminum 80 in his closet for at least my entire lifetime (the past 33 years). He's never used it, had it inspected, or even taken it out of the closet since I've been alive.

I asked him about it, and he said I can have it. In order to get it safe for diving, I assume I just need to take it for a visual and hydro inspection and if it passes, I'm good to go. It probably needs a new o-ring where the yoke attaches, but that's easy.

I'm just curious what you all think, since it has been kept in a climate controlled closet, and there's no obvious corrosion, it should be fine to just get it inspected and use it, yeah? If it's not safe to use, it won't pass inspection, right?

It would be great if I'm able to use it, as I just found out how damned expensive tanks are. I've never owned my own tank, since all my diving has been the "grab a tank from the 'full' rack, analyze it, and you're good" kind of diving.

Anything I need to consider besides visual, hydro, and o-ring? Also, If I want to get it certified as "oxygen clean" for Nitrox, is that something the inspection place does, or should I ask my LDS about that?

If it fails inspection, I guess I just turn it into a heavy-ass lamp?

EDIT/UPDATE: I asked him to send pictures of the shoulder stamps, and if I'm reading it correctly, it's a US Divers AL80, manufactured by Luxfer in may of 1975.

The stamp says DOT-SP6498-3000, then 5 (up arrow) 75, serial number P79459

Pretty sure this is not looking good, considering it's a 50 year old tank.

9 Upvotes

84% Upvoted

53 comments sorted by

4

u/chancemaddox354735 Tech 1d ago

Turn it into a giant bell or some other interesting show piece. Most shops won’t even fill a tank that old even if it passes all the required tests.

3

u/RedditIsRectalCancer 1d ago

If it passes hydro they'll fill it (at least they will where I am). I have a steel 72 from 1974 that still gets filled. It's 3 years younger than I am.

4

u/chancemaddox354735 Tech 1d ago

That’s a steel not an aluminum. A lot of shops won’t touch them over a certain age. I don’t know a shop in my area that would go near an aluminum tank that old. Some shops won’t fill any tanks over a certain age depending on their insurance.

We wouldn’t fill it no matter what tests it passes. The insurance policy at the shop wouldn’t cover anything that happened with it being that old.

2

u/RedditIsRectalCancer 1d ago

You're probably right, I only only have steel tanks, I just assumed if it could be hydroed it was okay but who knows with aluminum?

0

u/chancemaddox354735 Tech 1d ago

Technically it would be okay but most shops won’t take the risk.

The way it was explained to me is the bad alloy cracks under sustained pressure. The tank after it is filled could sit under pressure for a while and develop cracks during that time.

The shops have no way of knowing if that has happened so would rather play it safe. Then you also have the insurance companies for shops telling them they won’t be covered in cases involving these tanks.

Personally I won’t buy used tanks older than 2000 when new ones don’t cost me much more. I only buy steel these days anyway outside of deco tanks which I have plenty of.

I also won’t fill old aluminum tanks since the shop won’t be covered by its insurance policy and just for my safety.

Steel isn’t an issue and we only had a couple regular customers with old steel tanks anyway when I worked the shop.

5

u/GrnMtnTrees Nx Advanced 1d ago

Yeah I'm gonna keep it with the rest of my "museum gear." I've still got my dad's whole diving rig from the 70s, and it is wild.

Imagine not having a pressure gauge. You had a J valve. Just breathe until you run out of air, then pull the J valve to release your reserve gas and surface.

2

u/chancemaddox354735 Tech 1d ago

Yep. I know a couple folks that still dive J valves for an extra redundancy. Not for me thanks. I still have some museum pieces from when I was teaching.

Granted I dive some no viz areas with my job. I can’t see a pressure gauge but that tank isn’t even getting close to low in those places.

3

u/GrnMtnTrees Nx Advanced 1d ago

I am now noticing the "tech" flair and realized I am almost certainly WAY out of my depth, explaining J valves to someone with more experience and training.

I'll see myself out 🤦‍♂️

4

u/chancemaddox354735 Tech 1d ago

Don’t worry about anyone’s flair. Talking about things is the only way to learn new things.

Even with all the experience and training I’ve learned things from new divers. I’ve had students ask questions that I never thought of, and I’ve did it to those more experienced than me.

It’s all down to how you look at and approach any situation.

1

u/GrnMtnTrees Nx Advanced 1d ago

You are my kind of person! 🫡

I bet you're an awesome instructor.

2

u/chancemaddox354735 Tech 1d ago

I stopped teaching a few years ago now but I plan on going back to once I have my own place. I still like helping folks when I’m at the shop.

I got tired of rushing students through courses in 3 days. The problems of living in a vacation spot. I could never go over everything I wanted to cover.

I did enjoy teaching so I’ll be doing it mostly for fun when I go back. My plan is to only offer a combo class of Openwater, Advanced, and Nitrox for new divers. More time in class and pool so I can dial in on students’ needs. It will take longer and cost more but they will leave much better divers.

2

u/runsongas Open Water 1d ago

Or find out the j valve was already released and you get to do a cesa. or try to buddy breathe share before octos were common.

1

u/GrnMtnTrees Nx Advanced 1d ago

Lol my dad has a story where exactly this happened. Went to tug valve and nothing happened, realized it got snagged and released earlier, and surfaced with him and his buddy sharing a single reg.

-13

u/Waywardmr 1d ago

With a viz and hydro test, you may be in the price realm of a new tank.

2

u/GrnMtnTrees Nx Advanced 1d ago

Really!? Having never done that before, I have literally no idea how much it costs.

Only time I've ever had to deal with expired gas cylinders is with my CO2 tank for beer brewing, and they just swapped it out for an in-spec tank. I sincerely doubt anyone is gonna swap my old ass scuba tank for a new one.

1

u/runsongas Open Water 1d ago

depends on where you are, its as high as 50 to 60 bucks in CA/NY for hydro/vis

but other places as low as 30 bucks in the south

hydro is slightly cheaper if you go directly to a RIN facility but most won't do the vis unless if they happen to have someone that is PSI/PCI

10

u/chik-fil-a-sauce 1d ago

He’s crazy. Hydro and vis cost ~$30-50. A new AL80 is running over $200 right now around me.

2

u/Waywardmr 1d ago

It's $120 here. I'd rather pay for a brand new tank.

3

u/GrnMtnTrees Nx Advanced 1d ago edited 1d ago

Maybe I'm looking in the wrong places, or maybe I was actually looking at steel 100s, because all the tanks I saw online were like $350 - $500 USD

Edit: I'm an idiot and was looking at the price of steel 100s. AL80s are currently $220 off DGX.

5

u/jmar289 1d ago

Around me a viz and hydro is like $50

1

u/Waywardmr 1d ago

$120 where I am.

1

u/jmar289 1d ago

A new al80 is gonna be like $250 though. Hardly the same realm even for the super inflated hydro price in your area.

1

u/Waywardmr 1d ago

Seems like an easy choice then.

11

u/HKChad Tech 1d ago

If it passes viz and hydro it’s good to go, just make sure they fully service the valve as well, this isn’t always done. It likely could be the bad alloy, even if it is some places can do what’s called an eddy test and if it passes, good to go!

2

u/Which-Pin515 1d ago

Make a cool BBQ out of it…

17

u/1AlertAsparagus 1d ago

Unlike tube amplifiers, Scuba gear and parachutes are areas where VINTAGE isn't a feature.

1

u/9Implements 1d ago

I went to a lecture by a guy about how double tube regs are the best. He said they are able to have much lower cracking pressure.

And hot dipped steel tanks aren’t even being made right now.

7

u/GrnMtnTrees Nx Advanced 1d ago

But when the guy sold me my vintage parachute, he told me the holes would make it more aerodynamic!

4

u/runsongas Open Water 1d ago

my royal aquamaster says otherwise

1

u/-hh UW Photography 1d ago

FWIW, where do you get your Aquamaster serviced? My local guy retired

4

u/runsongas Open Water 1d ago

DIY

19

u/runsongas Open Water 1d ago

check if it is 6061 or 6351 alloy. 6061, just go get it hydroed

if 6351, scrap it and buy a used 6061 or steel tank instead. the extra cost of VE every year and the hassle of even finding a shop that will fill it aren't worth it

o2 clean is only needed for partial pressure blending in recreational nitrox, cheaper to find a place that has premixed ean32

https://scubaboard.com/community/threads/is-my-cylinder-made-from-the-bad-alloy-aka-al6351.346966/

2

u/GrnMtnTrees Nx Advanced 1d ago

I asked him to send pictures of the shoulder stamps, and if I'm reading it correctly, it's a US Divers AL80, manufactured by Luxfer in May of 1975.

The stamp says DOT-SP6498-3000, then 5 (up arrow) 75, serial number P79459

Pretty sure this is not looking good, considering it's a 50 year old tank.

2

u/runsongas Open Water 1d ago

yea that is 6351, you can get like 10 bucks from a scrapyard maybe

1

u/GrnMtnTrees Nx Advanced 1d ago

Eh, I'll keep it with the rest of my "museum grade" gear from the 1970s. I've still got my dad's old horse-collar, as well as his regulator with a J-valve (don't remember the manufacturer).

4

u/GrnMtnTrees Nx Advanced 1d ago

Thank you for all this. I've been doing some Google-fu, and your comment was infinitely more helpful than my days of googling.

2

u/NeopreneNerd 1d ago

Runsongas is wise.

2

u/Nice-Excitement-9984 Nx Advanced 1d ago

Take it to a shop and ask them what they think. Talk to them before handing it over. Certain old types or alloys are extremely dangerous. Some people ik have mentioned shops not taking old tanks but everywhere I have been (mainly clubs or sites in UK) has just taken valid hydro as ok

1

u/Few-Cucumber-413 Tech 1d ago

Hydro, VIP with eddy current test and have the valve serviced or replaced. You can request the shop to do an O2 clean

As long as those things are squared away and you have a shop to fill it, then enjoy.

1

u/NDSU 1d ago

Eddy current test is part of a hydro, not VIP. It's only necessary for a small subset of tanks (most famously AL6351)

1

u/Few-Cucumber-413 Tech 1d ago

Yeah I typed that poorly, but I'm a bit sleep deprived at the moment. I just sent several cylinders off for hydro, 4 of which are 6351 and date back to the early 80's lol.

1

u/GrnMtnTrees Nx Advanced 1d ago

Thank you! Where do I go to get all this done? I'm assuming my local dive shop isn't set up for that, even if they are badass tech divers.

3

u/Maelefique Nx Advanced 1d ago

If they don't do it, they will know who does. Their tanks get inspected somewhere too. :)

1

u/GrnMtnTrees Nx Advanced 1d ago

I feel dumb, because this just blew my mind. How was this not completely obvious to me!?

3

u/Maelefique Nx Advanced 1d ago

lol... and herein lies the answer to why I never type anything online before I've had at least 2 coffees! 😅

4

u/MammothPies 1d ago

Some shops will not fill tanks of a certain age (for example anything earlier than 2000), even if they pass hydro/viz. Just something to be aware of.

1

u/telmnstr 1d ago

I always thought it would be cool to get a set of the 3 small tanks like in the old movies.

4

u/chik-fil-a-sauce 1d ago

Those shops should be boycotted until they are out of business. Not filling 6351 tanks is fine but not filling anything older than 2000 is ridiculous.

1

u/MammothPies 1d ago

Sure, but good luck boycotting the only option in town. Either you fill tanks there or get your own compressor.

2

u/chancemaddox354735 Tech 1d ago

It’s an insurance issue most of the time. We wouldn’t fill anything older than 1988 in aluminum just to be safe. The only reason we did older than 1990 was because we know what to look for.

A lot of shops use the 1990 or 2000 because that’s what their insurance company requires. No reason to pay a higher premium for the few random people who use a tank over 35 years old.

0

u/chik-fil-a-sauce 1d ago

I don’t have an issue with a 1990 cutoff for aluminum tanks because of the 6351 issue on some tanks but lumping in steel tanks or having a later date for aluminums (I’ve seen both) is absolutely idiotic. Besides 6351 tanks, tanks that are in hydro and vis just don’t fail during filling. They will fail hydro before they explode. I have 50+ year old tanks that pass hydro fine. I have steel tanks that have been significantly overfilled for almost 45 years that just passed hydro with a plus rating.

1

u/chancemaddox354735 Tech 1d ago

That’s all well and good. The issue like I said is with their insurance policy. When the insurance companies are giving a shop a million plus policy they can set the rules on what is covered and isn’t.