Do you block sand primer on your cars paint job?

The only thing you will do when you block sand your primer is to make the car straighter. I painted my car black which is the most difficult color to look right and using a high build primer blocked it 5 times in one area just to get it right. This is a step that should be done to make your car look amazing. Do your first block with 150 next at 220 next at 320, 400 up to 600. Depending on how straight the car was to begin with you can skip the first couple of steps. As the car should be 220'd when you do your filler. You bet block sanding primer will only make it more beautiful make sure to use a board that is flat and depending on the size of the panel will determine the size of the board. Do your blocking with diagonal swipes only as back and forth motions will dig into the surface of the primer and make ridges.