While removing paint with 80 grit I got into the ABS on one of my mirrors. I've read that sanding ABS with anything coarser than a gray scotch brite is a no no because they will show through. Do I need to bring the ABS up to a 600 or 800 before the 2 epoxy coats and 2K primer or am I ok with 180 which is what I'll bring the body filler to before next epoxy coats?