Steel 72 worth it?

[Nemrod]

I would not purchase a steel 72 unless it is cheap, unlined, 3/4 valve (K valve), galvanized finish, current hydro with several years to go. I have quite the fleet of them, that said.

I drug some down to Florida a few years back. Getting fills is hit and miss. In fact, it is hit and miss anywhere. Arguing with pinheads just is not much sport for me anymore. I bought two aluminum Catalina 63s and use those now instead for road trip beach/shore dive tanks. I will not quibble over the 3 cf deficit, my SAC is sufficiently low to get me bent on them vs the 66 cf in a steel 72 or the 77 cf in an aluminum 80. For a dive charter, I expect them to supply tanks or if I need something special, I will just rent them.

I had an old USD decal on one brand new Faber steel LP 85. I had shops in Flaridah refuse to fill them because they were too old. Even when I pointed the manufacture date out to them and that they were only a few months old into their first hydro!!!!!!!! Pinheads!

N

 

[dylanshoemaker]

So I ended up picking up the tank, and it seems good, 3/4 valve, clean interior, no lining, was JUST hydroed last month. The only thing is when he pulled the boot of there was some minor pitting on the very bottom of the tank, but he said it was not even close to failing VIP. He vip'd it himself and gave me a sticker from a well known local shop he does visuals for. Is minor pitting on the bottom of tanks acceptable?

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[duckbill]

The fill station guy said, "I wondered who's those were. Don't bring them back here. I'll fill them this time, but not again. They are older than I am. There's no good reason when you can buy AL80s at the "big store around the corner" for $150."

"If that's an indication of your mental prowess, I don't want you touching any of my gear. My tanks won't be back here, and neither will I. Good day."

 

[halocline]

So I ended up picking up the tank, and it seems good, 3/4 valve, clean interior, no lining, was JUST hydroed last month. The only thing is when he pulled the boot of there was some minor pitting on the very bottom of the tank, but he said it was not even close to failing VIP. He vip'd it himself and gave me a sticker from a well known local shop he does visuals for. Is minor pitting on the bottom of tanks acceptable?

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It is for a year anyhow! Here's the basic scenario with visual inspections: Dive shops own the compressor, and they can refuse to fill a tank or issue a vis sticker for any reason they want, regardless if it's based on actual knowledge or complete idiocy.

Nobody on this forum can answer your question accurately because none of us know exactly what you mean by "minor". If there is any rust in the pits, I would be inclined to strip the paint (just use regular paint stripper) lightly sand the tank, and apply a few coats of a product called ZRC galvilite, which is an excellent cold galvanizing paint. I fixed up a few LP72s with this stuff several years ago and they've held up great. Galvilite is good for repairing gashes and scratches that go through original galvanizing as well.

Most 72s pass hydro easily; the test pressure is pretty low compared to most scuba tanks. Getting the plus rating is tricky because you need to find a hydro facility that knows anything about it and will accept the PST document floating around as an REE designation. If your 72 is a kidde or norris that could be tough to get the plus rating on. It hardly matters, though, you'd be amazed at the wide variety of fills you'll get on those tanks. Some shops won't fill at all, others will do 2250 no matter what you or the tank says, some will ask "how much air do I put in this thing" and I would point to the original "+" and say "2475" and they would do it, I've even had a few 3000 fills because the tank monkeys are so used to AL80s they don't even notice.

It's a crazy world.....

 

[oldschoolto]

I don't want to start a big deal... BUT, The amount of metal in the bottom of the cylinder is so thick that you would need some really deep rust to hurt the tank... I glass bead the bottom and then use a chrome-matte primer, Then topcoat the tank... I don't think I've seen a tank fail by splitting from the bottom ..

Jim...

 

[dylanshoemaker]

I figured he knew what he was talking about since his basement looked like a tech diving museum, but just wanted to make sure. Thanks everyone. Also, the tank has a thick yellow paint underneath that looks to be original under someone's spray paint job, will paint stripper be sufficient to remove this?

 

[Tracy]

Why would you say it looked like a museum?

Scuff the paint well with an 80 grit paper and then hit it with rustoleum aircraft stripper. Paint will scrape right off.

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[dylanshoemaker]

Why would you say it looked like a museum?

Scuff the paint well with an 80 grit paper and then hit it with rustoleum aircraft stripper. Paint will scrape right off.

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Just that he had an extensive collection of tanks, gear, and everything scuba and I was a bit in awe as an inexperienced diver. However, I'm sure that I would be just as impressed at many of these forum member's gear lockers. Anyway, i will definitely be picking up some stripper asap as the thing is hideous (like it really matters lol) but chipping sparkly purple over yellow is quite an unappealing combo! Thanks again to everyone for your wisdom and advice!

 

[Eric Sedletzky]

One thing you might want to consider doing with the rust spots is either lightly sand blasting the pits to make sure all the rust is out or at least neutralizing the rust with something like Naval Jelly which is a phosphoric acid gel designed to turn rust into black iron where it sits benign. If you don't kill the active rust or get rid of it completely it will just continue to grow. After neutralizing or removing I would just brush on some zinc rich primer (80% zinc dust - very heavy) and be done with it. Zinc against bare steel will outlast everything else for exception of water barrier coat epoxy mastics but that's a whole different industrial level

 

[duckbill]

i will definitely be picking up some stripper

Shame on you!:shocked2: (Wanna go halvsies?)