SurprisedOutlet
Registered
Got a used spare air for cheap and read here (somewhere) that paintball tanks have the same neck. So I got a used paintball tank with a hydro date of 10/2012 for $25. I figure it would be fun to play around with at the lake. Anyway, I dropped an LED down the neck of the paintball tank and there was a bunch of black residue or something on the inside. I don't want to breathe that so I rigged up a tank tumbler with my drill. I used rock tumbler grit with some steel shot and hot soapy water and tumbled it for a couple hours. The results were great, no more residue and nice sparkly aluminum on the inside. Here's the 5.4 cu. ft. spare air next to the original tank.