When going over bare steel, self etching primer is really not needed as long as the surface is entirely and sufficiently scuffed for the benefit of a good mechanical bond.

If the surface is insufficiently scuffed, a self etching primer or a metal conditionerwould be a good idea.

+1 on the epoxy primer.

Aluminum is a little different.

 

I would wire wheel it enough to insure that the rust is gone, prime with self etching primer and the put a top coat of rattle can truck bedliner. Just my opinion.

 

It wasn't hard to get mine to bare metal... but on the other hand I had a sandblaster

 

I'll use the wire wheel and show you guys what I end up with. Then you guys can tell me what I should do from there.

Seriously, this forum is basically like my restoration manual, it's been great and awesome.

 

not really supposed to get phosphoric acid on paint it will become contaminated, as far as prep i like to go to bare metal for my personal vehicles, depends if the customer wants to pay the money to strip theirs or not? if you use ospho dont use an etch primer also. id ospho then uses either por15 or an epoxy primer then a top coat. for leaving paints on without stripping the old ones depends if the substrate is good enough to do so. ford used enamels they are tough that why you see alot more original paint fords at shows etc. now if theres is laquer then painting over top of it with a 2k primer can cause it to lift and cause problems.