Tank Rust Removal Aternatives to Tumble

[bl6394]

OK I realize this is extreme necro-posting, and my first post to boot, but I felt compelled to log in and post and make sure that NOBODY follows derwoodwithasherwood's advice above about electrolytic rust removal. Electrolytic rust removal works very well and if you have the battery charger already it's super cheap. I've used it extensively for vintage car restoration. BUT YOU MUST NOT USE SALT. You use "washing soda" found in the laundry aisle.

Salt, under electrolysis, produces CHLORINE GAS aka chemical warfare. DO NOT USE SALT. Also do not use stainless steed rods for the electrodes, plain steel only. Stainless steel introduces hexavalent chromate into your electrolysis solution, which is extremely toxic and carcinogenic.

I would also hesistate to put antimony chloride and stannous chloride in my breathing air tank...

I'm don't know of there are any consequences of doing this on a cromoly steel scuba cylinder - but electrolysis worked very well on the rust in a motorcycle gas tank! Your mileage may vary.