I'm new to this Forum, I've checked out a couple of the Treads on this, but i'm not sure that My question was touched upon.
I have an old Dodge, In some places on the outside of the body there is "Surface Rust" Once I grind it down it went back to a metal color, but still have some small pits in it. Heres what my local Body shop supply gave me to solve this problem.
SEM -Rust Converter- The contents include Phosphoric Acid. Now they said to grind down the rust, apply the SEM converter, let sit overnight untill it turns black. Then Using 100 grit paper sand down and apply Etching / Filling Primer. Then using 200 Paper sand again, Use Etching / Filling Primer, then if there are still pits showing, go down to a 300 grit paper and then etch / filler prime again. This should bring back the level to that of the surrounding finish.
What my question is: Can i skip the sem converter, as once the metal is primed, and then topcoated won't air and moisture have no access to the rust, and therefore stop the rusting process?
Also, Isn't there supposed to be a step where i neutralize the Rust Converter? I always thought that products containing acid must be neutralized first.