I've read and read and I'm still very confused on this Epoxy 2K primer stuff. I'm not able to strip my 54 3600 down to bare metal all over and I cannot sand,do dent repair, prime and finish paint it all at once. I need to be able to do sections of the cab at a time. Can't I just spray the epoxy over the existing primer where I've feathered bare metal /filled areas into the old primer and painted areas? Any suggestions?