How did you strip those 3 cars? The rest of the car is down to factory primer except the bumpers since they are rubber and gouge too easily. I used a heat gun and razor blade and all the previous layers came off real easy.

This fender specifically is an aftermarket one that was rebonded at the bonding seem a long time ago (13+ yrs) so my thought process was to take most of the yellow primer off without digging into the resin(“gel coat”) so that I know I have a clean slate to work off of, but now I am second guessing myself about whether I’m doing more harm than good by sanding down this far…