MartinSR, I just re-read your "Bondo" and "Rattle Can" basics and have a couple of questions.
1. You mentioned that cutting the original filler is typcially done with 36 or 40 grit. You stated that you had to learn to use 80 at one particular shop because that is all they had. Doesn't / wouldn't the very abrasive grits mar the adjacent surface and/or leave deep gouges in the paint? Or, should the skim coat cover the entire are that has been sanded/scuffed? Is the rougher grit merely to save time and form the material quicker?
I ask as I have recently attaced the hood of an old jeep that met the windshield one too many times and needed some attention. I pounded the dents out and sanded down the paint and old body filler to bare metal. Then, applied a coat of filler, sanded, and applied a second coat (I wasn't brave enough to try the one coat, sand, and skim technique you recommend) of filler, sanded, then the final skim and blocking. It appears to be very nice. Although, it now appears that my skim coat does not cover enough as you recommed an overage of about 3".
2. How do you handle complex body contours and shapes such as creases? Specifically, how do you form and fix an internal crease such as around a wheel well? I am not sure how to explain this in greater detail.
3. Should bondo be applied only to bare metal? Or is it OK to go over paint?
4. After the skim coat (remember, I'm not a professional) should I prime and block again to verify that the panel has been properly repaired prior going to final paint?
5. When applying paint with a spray can, should I apply more coats of primer in order to build the millage? You indicate that the standard thickness out of a can is about 0.5 mil. How many coats out of a can should I apply to obtain a satisfactory prime level?
