You should paint over 400 grit. Allow the primer to dry for 30 minutes between coats.
Primer Surfacer Sanding
What grit to sand primer before base coat. Wet sanding epoxy primer is usually the best way to prep it because epoxy has a tendency to clog paper when sanded dry. After some time with the 400 grit you can move to a 600 grit paper to give yourself a nice smooth surface to work with when you are painting the car. The goal of sanding wood that has primer on it is to smooth down the grain that has risen while still leaving the primer intact so you do not lose the added adhesion that the primer will provide for the top coat. You can actually go even more coarser if youre doing a single stage enamel. To sand wood with primer on it you should consider a finer grit sandpaper like a 220 grit sand paper. Anything smoother and finer than that like 800 1000 12001500 gritis not good.
That is an excellent grit to paint your base coat and clear coat over including enamels or anything else that youre doing. Now were using the da sander to help me cut all of our filler primer with a 320 grit. Allow the parts to dry then wipe them with wax and grease remover. You dont want to cut too much and dont want to cut too fast either. You can use anywhere from 320 grit to 360 grit. You would sand the same way as 2k urethane primer400 to 600 grit wet.
Regardless of whether youve wet or dry sanded its always a good idea to go over your work with a gray or red scuff pad. As a starting point if you are sanding a coat of rough primer you can start with a 400 grit sandpaper to knock down all of those little bumps. Spray the parts with three light coats of primer. Keeping the sandpaper soaked with water use 1200 grit sandpaper to sand the primer until the parts are smooth and the primer is even. Were taking out all the sand scratches and orange peel to get it nice and flat. Honestly in my opinion i like 400 grit but 400 600 is a great range to put your base coat and clear coat over.
Some people even paint over 280 grit sanded surfaces.
Gallery of What Grit To Sand Primer Before Base Coat
