I am thinking about buying a pair of AL80s from craigslist. All the info provided is that the tanks were manufactured in the 80s and were last hydro in 1993. I understand these tanks are incredibly old but they are at a good price. I also understand that some tanks in the 80s were made from faulty aluminum. What kinds of things should I be looking for? Is a hydro/vis enough? Can they be re-certified by an agency to ensure they are safe?
Question about old AL80 tanks.
- Thread starter wesleyvb
- Start date
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There are TONS of threads on these tanks. Search "6531 scuba tanks" online and you will see.
The bottom line is this, will the shop you plan on getting air from fill them? Nothing more nothing less.
You will see advice from all over the internet that says you will die if there is one anywhere in your state on one end to they are fine as long as they are properly vis and hydro (this comes from professional testers).
No matter if they are safe, not safe, new, used, or whatever IF the shop you choose to use will not fill them there is no point buying.
The bottom line is this, will the shop you plan on getting air from fill them? Nothing more nothing less.
You will see advice from all over the internet that says you will die if there is one anywhere in your state on one end to they are fine as long as they are properly vis and hydro (this comes from professional testers).
No matter if they are safe, not safe, new, used, or whatever IF the shop you choose to use will not fill them there is no point buying.
They may be useful but as Nwcid mentioned finding an old aluminum friendly shop is step 1. Step 2 is hoping they stay that way.
Here's a little of the back story. Many of the cylinders from that era especially those from Luxfer and a few others (but never Catalina) were made from the mentioned 6351 alloy. This stuff has a cracking problem. They are still suitable for use with some elevated testing that comes at a premium cost. it may be eddy current testing and/or a microscope exam of the threads. Also some shops only recognize this testnig if they did it! More and more shops every year are just saying NO, go away.
On top of the mentioned 6351 issue more and more shops are black balling aluminum cylinders when they are 20 years old regardless of brand or alloy. If they are not 6351 there is no technical justification whatsoever for this, go figure.
In the end these cylinders may be difficult to get filled espcially if you travel around with them. Unless you have a real handle on the overall situation I would pass and hold out for something newer.
Pete
Here's a little of the back story. Many of the cylinders from that era especially those from Luxfer and a few others (but never Catalina) were made from the mentioned 6351 alloy. This stuff has a cracking problem. They are still suitable for use with some elevated testing that comes at a premium cost. it may be eddy current testing and/or a microscope exam of the threads. Also some shops only recognize this testnig if they did it! More and more shops every year are just saying NO, go away.
On top of the mentioned 6351 issue more and more shops are black balling aluminum cylinders when they are 20 years old regardless of brand or alloy. If they are not 6351 there is no technical justification whatsoever for this, go figure.
In the end these cylinders may be difficult to get filled espcially if you travel around with them. Unless you have a real handle on the overall situation I would pass and hold out for something newer.
Pete
The place I just went to for hydro won't do any Aluminum older than 1990.
Rich Keller
Contributor
It is the LDS that will not deal with these tanks, the hydro facilities the LDS takes the tanks to are run by the DOT and will do the test. Find your local hydro facility from this site and deal with them directly. PHMSA - Cylinders - Authorized DOT Cylinder Retesters: Domestic Not all of them deal with scuba tanks so call first before you bring your tank in. You can also get your tanks filled there without the need for a VIP if you use air, they will not do nitrox.
It's not worth getting the old 6351 tanks anymore, no matter what anyone says. Even if you do your own cylinder inspections and fills, you are still going to have to buy equipment to perform eddy current testing for the 6351s (unless you want to risk having one of your own tanks blow up on you).
The cost savings/benefit ratio is not worthwhile.
The cost savings/benefit ratio is not worthwhile.
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