Epoxy primer

Most epoxy primers sand like bubble gum. They roll up on the paper. One example would dplf from Ppg. It doesn't sand nice and anyone who has tried to sand it would agree. There are newer epoxy primers that sand much better these days.

If you don't have a lot of body work to do why not epoxy the car, wait a day and then high build prime the car? I've never understood why anyone wants to keep sanding an entire car over and over again?