How often do you need a tumble for a PST tank?

[AquaGuy]

I was getting a fill yesterday at my LDS and was talking to the guy filling up my tank about the difference between PST and Faber steel tanks. He said he prefers faber since faber tanks don't need to be tumbed every year like the PST tanks. I was not aware that PST tanks need to get tumbled on a yearly basis. Has anyone else heard of this? BTW the LDS does not sell PST, only Faber which may explain why he said what he said.

 

[roakey]

My PST 104s haven't been tumbled in years. Well, not quite, I just got one tumbled because of a little flash rust I finally decided to get out that was left over from the tumbling that I did a couple of years ago merely to O2 clean them; they looked perfect at the time.

Perhaps if the LDS is willing to insinuate that PSTs need to be tumbled, it should be insinuated back that they're pumping bad air, and THAT'S why they need to be tumbled.

Roak

 

[Rick Murchison]

It's not a question of time, but of condition. You tumble it when you need it, not on the clock. In all my steel tanks (5 of 'em) I've had a need for a single tumble - that was on a '72 at year 10 - it's now over 30 and I dove (dived, if you prefer) it Saturday.
Rick

 

[Bob3]

Perhaps if the LDS is willing to insinuate that PSTs need to be tumbled, it should be insinuated back that they're pumping bad air, and THAT'S why they need to be tumbled.

Right on, dry air makes no rust.

 

[Aquamaniac]

Rick Murchison once bubbled...
it's now over 30 and I dove (dived, if you prefer) it Saturday.
Rick

you pokin fun at me Rick???

 

[pescador775]

Fabers do have a beautiful interior finish and are more resistant to rust inside. However, PST is more resistant to exterior rust. Trade off. PST's will go five years or more (usually more) before tumbling is needed. My old Bauer had an obsolete condensator set and would inject a certain amount of moist air. Even so, the PST's went fifteen years before the rust got so bad that tumbling was required. The compressors manufactured in the present time, even the portables, use micronic elements in the condensators and improved dessicant chemicals in the final filter. These things are pretty effective and it would seem that tumbling would be much more rare than formerly. However, there is a trend to use enriched oxygen in SCUBA cylinders and this practice can promote rust. Just something to keep an eye on.

 

[thethumper]

Not to sound stupid.... But for some one who is about to but LP steel, what is tumbling.

Just taking a stab @ it, it sounds like you would use some agent or abrasive in the tank & have it "tumbled" to remove any build up of rust or other contaminents?

Am I close???????

 

[Compressor]

Yes it is too bad that aftr tumbling with the bare steel there, one cannot coat the inside of the tank with galvanized paint or finish of some sort. Is this possible or even advisable??


Does a tank need a tumble everytime there is a little rust in it??

I agree wholeheartedly that dry air is the key to a good rust free tank.

 

[pescador775]

There is no suitable aftermarket internal coating. The only factory coated tanks which I am aware of are the Faber which 'parkerize' the interior. This is a black oxide which resists powder rust but is not rust proof.

In years past, steel tanks were internally coated with epoxy (paint) and this was a disaster. Epoxy is porous and rust would form under the coating. Epoxy is hard to roll out, so the tank was typically condemned. (Think about that when buying a used tank).

Pesky

 

[LouieLouie]

It should NEVER be neccesary to tumble a tank. There are only two possible causes, and both involve people screwing up:

1. You empty your tank underwater.
2. LDS filled gas which didn't meed the required specifications.

You will not have rust if the gas is in compliance with regulations. Period.