I am painting my 72 corvette. It has the original paint and then it was painted once over it. The second job was nice but the car needed some cracks fixed. Block sanded the whole car got most of the second paint job off and it's nice and straight. I have a gallon of slick sand that I was going to prime the whole car and block it. Now that I have the car already sanded do I need to prime the whole car or just the areas of body work. I have SPI white epoxy I was going to put on after I sanded the primer.