Rust? after hydro on steel tank

[Jondjames]

Had my tank hydroed the other day and it passed, took a peek inside today and noticed small spots of what may be rust but I'm not sure? Is this normal?

IMG_1743

• Jondjames
• Aug 2, 2017

 

[Wookie]

I'd call that a lot of rust. It needs to be rinsed with a rust inhibiter and/or inerted.

 

[Jondjames]

Maybe it's the color of the lights that is making it look so bad? My concerns are the small dark spots, I can't tell if it's rust or not or if I should even worry about it at all since it passed hydro it should pass the visual inspection at my dive shop shouldn't it?

 

[WarrenZ]

If that were my tank I would tumble/clean it then dry it properly before using it.

 

[tbone1004]

looks like flash rust and some spots that likely showed up over time. Not something to be terribly concerned about, but it should at least get a whipping if not a tumble. I treat that as SoP after hydro for all of my steel bottles

 

[Jondjames]

I had plans to put it to use this weekend on a trip to mermet springs, I doubt a whipping or tumble could be done before I leave on Friday, is It something that can wait until I return maybe?

 

[tbone1004]

I had plans to put it to use this weekend on a trip to mermet springs, I doubt a whipping or tumble could be done before I leave on Friday, is It something that can wait until I return maybe?

as long as you aren't PP blending I'd have no problem filling it with air or premix nitrox. Others may not, but to each his own

 

[oldschoolto]

I'd fill it... Dive it this weekend and then tumble it when I got back... But, Everyone knows I am always running against the wind..

Jim...

 

[Jondjames]

OK. Cool thanks a bunch. This will be my first time diving a steel tank and was excited to put it to use. I'll be sure to only fill it with air and have it tumbled when I return : )

 

[JamesBon92007]

Well, I whip my tanks myself, turn them upside-down to dump out the rust powder, and then rinse them with boiling water. Then I turn them upside down again and blow them out with scuba tank air and let them dry in the sun. When they are thoroughly dry I attach the valve and fill it. So far this has prevented "flash" rust from forming.

If you take your tanks to a dive shop to get them hydroed they are likely to offer whipping or tumbling for an extra charge. If you take it yourself to a hydro station they seem to just dump out the water used for the test and dry them with compressed air, probably not from a heavily-filtered source such as a scuba tank. Mild flash rush is considered to not be a problem however if you have rust "spots" I would want to inspect them to be sure they are not pits and remove any loose rust. Basically, before a hydro test the tester will inspect the cylinder and if it does not pass their visual they won't hydro test it so I'd say your tanks are probably OK. Personally I would not use the tank until inspecting it further but I have a bunch of tanks. As someone else pointed out the light you used could cause them to look more brown inside than they really are.