Buying used gear-tanks

[Kwbyron]

Couple questions about what to look for and/or ask about when Tanks, How long do they last? I mean, how old can a tank be before it wouldn't pass hydro? Is there any way to find that out before making the purchase? I'm looking mainly at steel tanks.

 

[SparticleBrane]

It depends on both the material and how well you treat the tank.
For aluminum, many shops refuse to fill them after 15 years. This doesn't mean that they don't last longer than that--it's just that they don't trust them perhaps as much as steel.
With steel tanks, if you treat them very nicely, they could last you a lifetime. I saw an oxygen cylinder that was first hydro'd in the 1950s while working at a dive shop.

Generally, if you overfill a tank then most people say it shortens the life. Just to be on the safe side I would probably agree.

As to age before not passing hydro--I've heard of tanks that won't pass their first hydro after being purchased (assuming a new tank, 5 years from the purchase date) but these are quite rare. I've seen plenty of aluminum tanks that have hydro dates stamped down the side. If you can find them you can find some steel tanks with 5 or 6 hydro dates stamped in the side!

 

[Kwbyron]

How long is hydro good for?

 

[SparticleBrane]

A hydrostatic test is good for 5 years.
VIPs are good for 1 year.

 

[TheFoggyMask]

Steel tanks last longer than aluminum, as for exact years I'm not sure. Nothing will last you forever though. I would not buy any tank online thats much older than ten or fifteen years unless you can physically inspect it yourself. Things you're interested in with tanks is last time hydro'd and last time visually inspected and how old it is.

 

[SparticleBrane]

Dude, aluminum tanks will last you a good 10-15 years minimum if you play nice.
Steel? At least 20-30 years; again if you play nice.

If you let the tanks corrode or rust out, you can't blame me if they don't last that long.

 

[SparticleBrane]

Not to scare you but this is what happens to steel tanks if you let them rust.
Note that this is an EXTREME example--these are some tanks from a shop in the Keys. They are used multiple times per day, might be hosed off at the end of the day (emphasis on might!), and never have the tank boots removed. They are left on the boat overnight.
Eventually the salt just destroys the finish and then the rust takes over. I would attempt to guess an age for the one with the rusty bottom but it had so much corrosion on it that I couldn't read the first hydro date.

These are PST LP80s. The one on the right is essentially new, but it'll look like the others after several years. Still--let's think about this. The older tanks in this picture are at least 3-5 years old. They're used literally every day, several times per day during the summer--in the conditions described above. Except for the one with the rusted bottom, they're actually looking pretty good.

The chances of your tanks ever looking like this? Zero to incredibly slim--but I hope that this picture makes people at least think about how they treat their gear.

 

[Kwbyron]

Thanks for the info. I was digging through classifieds looking for a punching bag, and came across quite a few scuba ads... it seems most cases are people who jump in gun-ho and then let every thing sit for several years. when they don't do it as much so they just want to sell it all off. What can I expect to pay for a visual and hydro? I know that hydro is a little pricy, so I'd try to make a buy pending visual inspection.

 

[divecon15]

There is NO WAY of knowing how long a tank will last. Steel do generally last longer but I have seen steel tanks that not that old sent back failing hydro. Some one said that there are some shops might filling aluminum tanks after 10-15 year. As long as it has a current Hydro (within the last 5 years) and VIP sticker (within the last 12 months it can be filled. Your best bet is to make sure that it is totally current with both Hydro and VIP.

 

[Don Wray]

My last hydro was $35 and the tank failed....it was an old steel U.S. Diver someone had given me...although it had been stored with air in it, it still failed the hydro. VIP is usually around here $15.....the first questions I ask when looking at a used tank is was it stored with air in it and where has it been stored. You also need to be careful on some of the older Luxfer tanks...they had a problem with them at one time and shops won't touch them for fills.