TheSneeze wrote on 01/06/24 at 21:28:12:Evap-o-rust works great. Just be warned, it outgasses when it's working. I used it on a fuel tank and had it sealed. It ballooned the tank. Always leave that stuff vented while using.
Wow....I didn't know that. I have put rubber plugs in fuel tank neck holes and not had a problem.
It works much faster if you can get it warm/hot. Above 70 degrees is good.....setting it in the sun and getting it hot to the touch is even better. Having the fuel tank full is better than partially full - although you can roll it around and keep the interior surface wet and that will also work......adding a handful of drywall screws and shaking helps to remove the rust as well (The drywall screws and shaking works best with only a small amount of Evaporust inside).
I rinse the tank with E85 from the gas station - as rinsing with water always seems to cause flash rust on the clean steel.