Rust on tank from crash

[jtopiso_imp]

I used a product called evaporust on the inside of a gas tank that was severely rusted, and it really did work. I read that filling a gas tank with vinegar and letting it soak would work, but absolutely not for me. Like somebody else said, it it's on the outside, just sand it off.

Any acid (like vinegar) will help removing rust from steel.

Sanding it with sandpaper soaked in diluted acid (or vinegar) will help to get a cleaner surface, as it will remove small spots of rust that might be invisible to the eye, thus slightly protecting the steel until painted (which should be right away).