Yet another LP 72 question

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Basking Ridge Diver

Contributor
Messages
1,968
Reaction score
1,015
Location
New Jersey
# of dives
200 - 499
All -

Threads on LP 72's have got me thinking about buying a pair - I would like to use them as ID's. I fill my own air so the issue of fills is not a problem.
I currently own 4 AL 80's and 2 LP Steel 85's and two ponies - all singles.

I am not sure he will let me drain the tanks and inspect the inside - is that a deal breaker and should I just walk away?
I have seen where other threads have said anywhere between $30 and $40 is fair per tank - based on the photo these look in pristine condition. Do I need to go to $50?

They are 1972 PSTs - they currently have air in them and have not been Hydro'd since they were born 10/72.
He currently wants $150 - I want to inspect them and if clean inside would offer $100. If he does not allow me to inspect should I even throw in an offer of
$60?
PST 72s.jpg

Any comments would be appreciated.
 
I would not think about buying these tanks without inspecting the inside. They have never been looked at in 44 years. Pristine outside means nothing. If there has been even a tiny bit of condensartion they are probably worthless. Selling them full is bogus. Would you dive air that has been in the tank for 44 years. Actually, I wouldn't buy them unless I could take them to my LDS and have a vis done.

I bought two LP PST's (one 80, one 72) for $100 so I wouldn't go above that. You will need to get them hydro'ed and vis'ed - not especially inexpensive. One thing to check. Make sure thay have the REE stamped on them. Without that I couldn't get the plus hydro on the 72 so it ended up a 65. I found out what the REE was but the facility wouldn't do the plus rating unless it was stamped. Also, was the original hydro a plus rating?
 
There are a few potential issues.

As noted above, these tanks have sat unused a long, long time. If they had a moist fill and then were exposed to hot and cold cycles (such as stored in garage in cold winters) condensation could have resulted in enough rust to cause a pit inside the tank and that's what kills most steel tanks.

Also, US Divers and other companies sourced tanks from PST and then had an internal coating applied. This was usually a light brown or tan epoxy coating and the intent was to seal the inner surface from moisture to prevent rust. It worked, well, until the liner cracked or developed pin holes. Those defects then let water in between the liner and the tank, resulting in rust, and worse made it hard to spot early in the process.

As a result no one with any knowledge of the issue will pass a steel 72 with an epoxy liner. It can be removed but you'll need to dry tumble the tank with an aggressive oxide media for about a week to remove it. If you don't have your own tank tumbler, you'll need a sympathetic shop that won't charge you an arm and a leg. Even then, once the liner is removed, you may find a rust pit that will condemn the tank.

A third issue was the practice of dip coating tanks with a thick outer coating much like the plasticote coating on tool handles. It worked fine until the coating was compromised, at which point it would hold water against the steel. And once again a qualified inspector won't requalify the tank as the coating prevents proper inspection of the tank. It can be removed with a can pf paint stripper, a plastic scraper and some elbow grease.

What you'll find underneath however will vary. If the tank is galvanized you'll probably have a great tank with nearly new looking galvanizing. If the tank is not, you'll either have rust pits and a wind chime, or you'll have an ungalvanized tank prone to rust unless you paint it. Paint is hard to maintain on a scuba tank, even if you use Imron or some other expensive finish. Your best results will be with ZRC cold galvanizing compound, but it's expensive at about $60 per quart.

Consequently, I would not offer anything for the tank unless you can either:

1. look inside to verify there is no liner, no rust and no pitting, or

2. get assurance that you can get your money back if it won't pass a requalification (which includes both a VIP and a hydro test).


Steel 72s are becoming more popular as they are a superb side mount tank. However, they are also a bit a of an oddity given that as a 3AA steel tank they have essentially no life limit if properly maintained 0 but as steel tanks that haven't been made since the late 1970s, they are all old enough that you have to worry about how well they've been cared for.

Consequently, in current hydro and with a current VIP, I'd happily pay $100-$150 each for a galvanized steel 72. However, for an unknown steel $72 I won't pay more than scrap metal value, as the cost of tumbling to remove any accumulated rust and/or a liner followed by requalification can run $50-$75, and then there's no guaranteed it will pass.

----

I don't worry about plus ratings on steel tanks. It's hard to find a RIN that will plus rate any steel tank, even if you have proper documentation from the manufacturer, as most are too lazy to do the extra calculation and paperwork. You can't get a plus rating on a Exempt or Special Permit steel tank and my other steel tanks al get cave filled anyway.

Most shops in cave country will still fill a properly certified steel 72 in good condition to 3000 psi (short of the 3375 psi that would be equivalent to a 3600 psi fill in a 2400 psi tank, but it's still 86 cu ft), and I normally fill mine to 2800 psi off my compressor, which is 80.5 cu ft.
 
One note; the REE will definitely not be stamped on the tank, but that should not deter you from buying them if they are unlined and in decent shape. I would bet more than even money that they are galvanized under the paint; if so, you can remove the paint, and touch up the galvanizing with a product called ZRC galvilite. It's excellent.

I have had an adventure getting the plus ratings on my PST 72s. There is a PST document floating around (probably available from the vdh site) that lists the REE for their 72s, and I have not had a problem getting hydro shops to accept it. That is, hydro shops that are willing to give a plus rating on any tank, and those shops are few and far between in my neck of the woods. Thankfully, it's only every 5 years. Around here, shops will fill mine to 2500, but my kidde 72 (no plus rating) only to 2250. Every once in a while I get a tank filler who assumes the only tanks in the world are AL80s and fills them to 3000.

I've also had a hydro shop get very angry when I described them as "low pressure" tanks after he was insisting that they were "high pressure." He almost threw me out of the shop. (I guess the stress of testing all those fire extinguishers really builds up....) but to him, any scuba tank is "high pressure."

Actually, hydro shops around here do all sorts of funny things. The last time I dropped off two catalina AL80s, about the same age, one of them came back with a VE test for an extra $3. The explanation was that "they all need the VE test." I guess the other one was a conscientious objector.

I dropped off a friend's relatively new faber LP80 once, with the REE stamped on the tank, and asked for the plus rating. "No problem" was the answer. I picked up the tank, brought it home, then saw that there was no plus rating. "Sorry we can't do any plus ratings" was the explanation on that one.
 
I have 4 72s. One is a voit that was born in 64. Older than me. Like it alot. Got it for $20 + another $20 for the hydro. The others are mid-80s pst. One is a mp 72. The others are a matching set so I doubled them up. Average price including hydro and vip is $75.

I have a nice dive rite manifold (din) that I picked up for a good price $75 which I used. Your valve is a j-valve? Might be ok but it might not be. Also, if not parts may not be available. If you can get the tanks for 50 and then get new valves and hydro you should not be in too much.

Now we have enough gas to explore a little further at round valley or some more bottom time offshore.

Another thing about the Lp72s especially as doubles is their weight. They are very manageable on the boat or on a shore dive.
 
/....I've also had a hydro shop get very angry when I described them as "low pressure" tanks after he was insisting that they were "high pressure." He almost threw me out of the shop. (I guess the stress of testing all those fire extinguishers really builds up....) but to him, any scuba tank is "high pressure."

He's not incorrect in the general sense, as the DOT considers anything over 800 psi to be a "high pressure" tank. But he's also telegraphing some serious ignorance about scuba tanks in particular.

hydro shops around here do all sorts of funny things. The last time I dropped off two catalina AL80s, about the same age, one of them came back with a VE test for an extra $3. The explanation was that "they all need the VE test." I guess the other one was a conscientious objector.
I understand that dive shops might need to take short cuts given turn over in tank monkeys and generally low training standards, so assuming every Luxfer aluminum tank made prior to 1990 is 6351 T-6 alloy is probably inevitable. But how hard is it to recognize that Catalina has always used 6061-T6 alloy? And if you're a RIN you not only should know that already, but you should know how to look it up.
 
Carl,

I have two 72 twinsets and two singles, love them. AND two spares. Fallout from Evie Dudas' shop closing. The spares are 2013 hydro'ed but out of VIP (the middle of last year, no biggie). They have been pampered all their lives. PM me for a "dive buddy" price if interested.

BTW, Thanks for releasing your claim on these. You know who you are...
 
Carl,
PM me for a "dive buddy" price if interested.

PM sent... :D

Good deal Kevin - I am looking forward to some more diving and more dive time...
 
Sold.

The one on the right is a US Divers born 1971 with a plus rating. Thermo valve 3442 DIN/Yoke with insert.

The one on the left is an SRP-PST born 1973 with a plus rating. Thermo valve 3000 Din/Yoke with insert.

It kills me to see quality stuff like this just sitting around. I have all I can use, so glad they found a home with a local diver.

:D

Your Tanks.jpg
 
If you ever need more, I know it is a hike, but I have about 30 of them in my basement at any given time, all with fresh hydros and VIPs. I sell them for $75 each.
 
https://www.shearwater.com/products/teric/

Back
Top Bottom