Flash rust in O2 bottles

[Enevoldsen]

Hi
How do you avoid flash rust, when O2 cleaning your RB tanks for 100% O2?

I find it extremely difficult, even when i do the final cleaning i near boiling water, and uses scuba-air afterwards to flush the water out.

Hit me….

 

[Garth]

Use enough air and have the bottle upside down completely you should be good. If you use 1/2” pex to get the air up into the cylinder that should help. You could try a rust inhibitor at the end of your process but as long as you do things quickly you should be okay without it.

How much air are you using? I use between 500-1000psi of an aluminum 80 to ensure it’s dry.

 

[Enevoldsen]

Use enough air and have the bottle upside down completely you should be good. If you use 1/2” pex to get the air up into the cylinder that should help. You could try a rust inhibitor at the end of your process but as long as you do things quickly you should be okay without it.

How much air are you using? I use between 500-1000psi of an aluminum 80 to ensure it’s dry.

Thanx - i will give the pex tube a try

 

[Eric Sedletzky]

Hi
How do you avoid flash rust, when O2 cleaning your RB tanks for 100% O2?

I find it extremely difficult, even when i do the final cleaning i near boiling water, and uses scuba-air afterwards to flush the water out.

Hit me….

I O2 cleaned tanks by doing the whole simple green thing, then chasing all that out with distilled water. I turned them upside down to drain hanging in a special holder I fabricated. Then I took a bottle of C02 (which I have around for portable compressed gas for running air tools) and hooked an air blower up to it and blew out the remaining water out of the cylinder. I made two different blowers by soldering a long copper tube onto a regular trigger blower. One was straight for the bottom area, and the second one had a bend in the end so I could blow all the water out backwards from the walls and neck area. Some people use dry nitrogen for this too.
After blowing it for a while I looked inside and the steel was perfectly grey and it was dry, no flash rust. Deny oxygen and there will be no rust. Then I purged out any remaining C02 with clean tank air and was done.

 

[flymolo]

I use this stuff. You mix 1oz to a gallon of water:

Compound O - Oxygen Safe Rust Inhibitor - Gallon

john@northeastscubasupply.com

northeastscubasupply.com

 

[Garth]

I use this stuff. You mix 1oz to a gallon of water:

Compound O - Oxygen Safe Rust Inhibitor - Gallon

john@northeastscubasupply.com

northeastscubasupply.com

I have this and have used it but don’t see a difference as long as you dry it well with enough dry air. I have a large dive compressor which makes that easier with dry air available. Most of the people I see with rusty tanks are getting bad fills from poorly maintained compressors or inadequately dried tanks after hydro or cleaning.

 

[rddvet]

I can tell you one thing to avoid: being a moron and using 32% nitrox instead of air to dry out the tank. Ask me how I know.
Compound O definitely works. Its not necessary but it definitely is a great cheat

 

[TrimixToo]

Compound O and using breathing air for drying. Having one's own compressor makes this easier. It takes somewhat less than a steel 72 or AL80 of air to dry a tank thoroughly. Seal it up immediately so water from the ambient air does not condense on the inside of the tank.

 

[mr_v]

Blue Gold. $40 on amazon with $4.99 shipping.

It is too expensive to use on everything, but that's what you need for steel.

 

[Matan]

Blue Gold. $40 on amazon with $4.99 shipping.

It is too expensive to use on everything, but that's what you need for steel.

What's special about it compared to simple green/etc. ?

Matan.