Let see if this makes any sense Allen. You've sandblasted all
the old paint, primer, fillers and rust off the metal leaving
a rough (etched) surface. So...why would you need to etch it
further with an acid? Etching primer is used on bare metal
to give it tooth, how much more tooth do you need beyond
sand blasting?
Here's a fender & running board that 8 years ago were blasted
with black max then primed with PPG-DPLF. The running board
was painted with Rustoleum the fender is yet to be finish
coated. The truck has been driven all that time as is and
I've put about 10K on it. It's been parked in cold garage
in the winters, and she's been caught in the rain many times.
No signs of rust:
http://www.pbase.com/dennygraham/image/156702149/largeDG
