[askmrjesus]

I've used two methods, both were a huge pain in the ass.

1. Methyl Ethyl Ketone, shake well, repeat, (get it on the outside of your tank, bye-bye paint).

2. For really messed up jobs, I've used rock tumbler medium, but the rust would have to be pretty bad before I went that route, because you have to spin the tank for hours to make it work. It also requires building templates to hold the tank, and a motorized roller (like a modified rock tumbler).

I used to used KREEM for re-coating, but there is some stuff called Red-Kote that works better.

JC