Cuudak are youyou sayingwith not to go to bare metal whentrimmed refinishing? But isn't it bad to put new base coat and other non laqure finishes over old laqure
Not when you use 2K epoxy sealer. This "Completely" seals the substraight. Done it many times.
The condition/thickness of the finish determines whether or not I choose to reach metal when I am sanding. Chips and scratches also come into play.
If you have to take a car/panel to bare metal you MUST condition the metal. Acid etch/wash is vital to prepare the bare metal surface before anything can be sprayed on it. That is unless the sealer you choose has etching chemicals within. I use PPG Dp90LF on most projects. Even with the Dp90LF I still apply GEM with a squirt bottle and a lint free cloth and dry scuff it with 180 once cured.
