Scuba Cylinder Cleaning

[turfy77]

I just opened up my scuba cylinder for the first time, its 3-4years old, I had it from brand new and I fill my own tanks on a private compressor. I noticed on the bottom of the tank there are lots of little specs of rust about 2mm diameter and on the side walls about 10 rust spots about 1cm diameter. On the valve thread at the very bottom and only on one side there is a slight bit of rust on the bottom 2-3threads. Is this anything to worry about? My guess would be the rust forming at the bottom of the thread is the biggest concern.

My second tank was the same as the first expect no rust starting on the thread. There were a few spots about 1cm diamter and only looked like surface rust, would a dive shop during the hydro test actually clean all this up or would they leave it to get worse? At what point would a dive shop decide to clean the tank?

 

[The Chairman]

Tumble it and treat it. No moisture in the tank, I presume? If so, check the filters and water separator.

 

[turfy77]

nah no water at all.

I don't have access to that equipment and don't know how to treat it. This is the first time Ive ever looked in a tank so all new to me.

I plan on getting it hydrotested at 5 years, in the meantime I might just put the valve back on and keep using it. After all its only a 3 year old tank.

 

[The Chairman]

Sooner is better than later. But hey, they're your tanks. Unlike aluminum, steel keeps oxidizing once it gets started. Unless you stop the process, it will keep producing that rust dust that will have to be filtered by your regulator. I'm very uncomfortable with rust in my tank, especially if it's accumulating in the bottom.

 

[turfy77]

Thanks for the tip, I did see a couple of tiny specs of rust dust at the bottom, there was bugger all but there was some there. If you added it all together it would be the size of a pin head. I blew it out with a compressor. Ive read about these tank cleaning whips you can attach to a drill, have you had any experience with these things? Are they any good?

 

[The Chairman]

You know, I actually own one and forgot all about it. They aren't expensive and if it's really light, I would give it a try. Just don't forget using a rust inhibitor afterwords like this one from Notheast Scuba Supply : Oxygen Safe Rust Inhibitor - Gallon