CollisionBlast.com- In this video we are demonstrating how to block sand primer surfacer. 1. Apply guide coat to the surface. 2. Using a block and 320 grit snadpaper, cross sand the surface. 3. Sand the surface until all guide coat is sanded off. If you sand through the primer surfacer [Read more…] about DIY – How-To Block Sand Primer To Get Ready For Paint – Auto Refinish Training Video in HD