My rear fenders were very bumpy. So it was hard to sand all of it, I'd just get the high spots. So I took a wire wheel on a angle grinder. The rest of the fender I used 80.
I started skiming it tonight. I'm really likeing the way it looks. I went to bare metal. I used something called Final Klean, I think that's what it's called. To wipe it down before I applied the filler. The guy I work for has painted cars before, I have his help. I just wanted a second opinion per-say.
We epoxyed our '47 but when we sanded looking for low and high spots we sanded through a lot of it, even though some stayed.