My buying used steel tank experience.....

[captain]

Liner is not automatically a no go. Basically it is a type of epoxy paint. One was a brownish red that can resemble flash rust but shiny, the other was off white. Just like any paint on metal if there is rust under the paint the paint will blister and flake off, no blisters or flaking no rust underneath. If the lining shows no blistering or flaking there is no reason to remove it. If there is blistering or flaking it is only necessary to tumble it enough to remove the blistered lining to be able to see the extent of the rust.

 

[Recneps]

BS is right. Recently picked up (free) 2 steels born in 1974 and 1976. One lined, the other not lined. Both were sitting unused and full for the last 15 years. Took them in to get a hydro. Both are now stamped, stickered and full, just waiting to get wet.

 

[Wookie]

Remember the VIP is a scuba industry standard.

Not true. An ANNUAL VIP is a scuba industry standard. A VIP is a part of the hydro procedure, including checking for cracks on older aluminum cylinders.

 

[captain]

This is the requirement from DOT page 1129, visual inspection, paragraph f section 2

"For each cylinder with a coating or attachment that would "inhibit" inspection of the cylinder that coating or attachment must be removed before performing visual inspection."

http://www.ctcseminars.com/files/cfr/49cfr180.205.pdf

Notice it doesn't refer specifically to either the inside or the outside of the cylinder just "the cylinder", then it would require any coating on both the inside and outside be removed. How many of you have had the factory paint on the outside of your cylinder removed for inspection.

 

[Wolfie]

got 3 old 72's
love um
nobodies gonna take em from me.........

 

[Jim Lapenta]

The liner is also an item that may or may not be a go/no go for nitrox if using partial pressure blending. If you can't get the entire lining out it should not have pure O2 put in. But no issue with regular air. Tumble until no more flakes off and fill if it passes hydro. And the 25 year thing is pure horseshiite. Or ignorance. There's a shop in WVa that will not fill any 72's and they supposedly are a tech oriented shop. I'd love to see their faces if I brought my 72's from 1953 and 1955 in. Both just passed hydro but I only use em for the bench for servicing regs. Both O2 clean and other than the pipe thread valves look as good as my 95's that are 42-44 YEARS younger.

 

[Gilldiver]

Disclosure, my oldest tank is from 1960. I could have older but just don’t want to deal with the ½” pipe thread valves.

The steel 72 is a 3AA steel molly alloy and age in no way caused any problem with them, it is how they are treated. If this shop still takes that stance, ask them how old the 200 or 300 cubic foot tanks in their air bank are, or just look at the ages of the O2/He tanks they may have. Tanks from the 1930’s are quite common in any compressed gas shop/supply house and the oldest bank tank I have seen is from 1909.

The epoxy liner was put on the ID of tanks in the early 70’s in order to protect them from rusting if water got into them. This was a period when the SCUBA yearly inspection program was just getting started, For the first 20 years of SCUBA there was no such requirement. Some SCUBA shops will not fill a resin line d tank as they can’t see if there is rust or pitting under it. As Captain pointed out, you have the same problem with paint on the exterior of a tank – so how do they do that? You can inspect a resin coating, but it takes a good light and some time. Removing the epoxy can be done by shot blasting the interior or by tumbling a tank. But when you tumble the tank you need a cutting media, steel deck screws work well. Then do a final tumble with regular media as a final clean up.

I would not do PP Nitrox blending in a tank with an epoxy liner.

With some care, a vintage steel 72 with a hot dipped galvanized outer coating has years left and can be used by your grandchildren in 50+ years.

 

[akdeepdiver]

I am raising the BS flag on your LDS. I personally have over 20 tanks that I dive with (not including O2, Argon, cascade tanks, ect). I have two sets of doubles that were manufactured in the 60's and 70's. All of my tanks get a hydro aprox every 3 years (due to constant use and the fact I own a hydro facility so it costs me nada). If you have any questions send me a email or PM and I will point you in the right direction.
Myles

 

[Scared Silly]

Not true. An ANNUAL VIP is a scuba industry standard. A VIP is a part of the hydro procedure, including checking for cracks on older aluminum cylinders.

I could have been clearer but to be technically correct the visual inspection program (VIP) is scuba nomenclature and not DOT requalification nomenclature. And thus as scuba nomenclature I was implying the annual visual inspection. And, what folks call a hydro test is really a requalification test which is comprised of a visual inspection and a hydrostatic test. But we are picking nits here.

But back to my point about not having the shop condemn the cylinder based on their VIP views is because once condemned the cylinder is toast. If the cylinder passes the requal but the shop will not pass the VIP for their misguided reasons the OP can at least resell the cylinder or perhaps get their money back from the seller.

 

[Mitchell Teeters]

I am raising the BS flag on your LDS. I personally have over 20 tanks that I dive with (not including O2, Argon, cascade tanks, ect). I have two sets of doubles that were manufactured in the 60's and 70's. All of my tanks get a hydro aprox every 3 years (due to constant use and the fact I own a hydro facility so it costs me nada). If you have any questions send me a email or PM and I will point you in the right direction.
Myles

Myles, thanks. I'm going to call them and make sure they do not condemn the tank. Really though I'm screwed if he just flat refuses to fill the tank even if it is cleared by the hydro. I may need to replace the valve also.