Evaporust containers
I just de-rusted the backside of my 1964 Valiant front Bumper and repeating on my 1965 Dart rear bumper. I first wire-brushed, then placed rags soaked in Evapo-Rust, covered with plastic for several days, brushed and washed again, then phosphoric acid to convert any remaining pits to hard iron phosphate, then Ace spray metal primer. Also did the rusted steel brackets which cleaned up nice. Not necessary since such thick metal won't rust-thru, especially in CA, but I never re-install corroded parts. The brackets fit in a large thin plastic food container, which wifey didn't even notice was missing.