Reviving this thread with a few new questions:

So I've replaced my gas tank and re-done the body work I'm trying to improve and I just put Urethane primer on this weekend. It has a pretty textured surface that I am going to sand before top coating to try and get a better finish than I did last time. Since my truck has such a curvy body style I was thinking of using those foam sanding blocks that are fairly rigid but give some flex.
I thought that may be good because the fenders have so much contour a block would be tough. Any suggestions in that area would help since I've never really done the sanding before. My last paint was just black epoxy primer so it looked good without anything, but this time I'm doing a urethane top coat.
That leads me to the next question. The paint can instructions say "allow 10 minute flash between coats"??????????
This is ultra confusing for me because it takes practically 45 minutes to do one full coat on the vehicle, or at least 30 at best. I just don't understand what that means because although I am certainly an amateur painter I know there's no way anybody could do that job in 10 minutes regardless of experience, so how does a 10 minute "flash" even apply to painting a car?
Does this mean I should just take a 10 minute break after finishing before starting the next coat or just continue because I already missed the 10 minute window?