Im in the process of stripping my 69 coupe. Im taking off about 3 layers of paint. Under the paint is a lot of little bits of surface rust. Still very solid, but lots of little spots here and there. These are the areas where the paint was chipping and cracking on the old paint job. Im using 40 grit with a DA, then plan to go over again with 80 grit before priming. So what should I do with these little rust spots? Looks like the last guy who did the body work just put bondo over the rust, causing everything to peel and crack after a few years.