How to Block-sand a primer coat to prepare for auto body paint

Before painting your vehicle, you'll want to sand down the primer coat. This automotive video will show you how to block-sand the primer to prepare you for the actual paint job. It's actually a pretty simple step in auto painting.

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 sandpaper, cross-sand the surface.

3. Sand the surface until all guide coat is sanded off. If you sand through the primer surfacer and the epoxy, you will need to re-prime and block.

4. When all guide coat is sanded off and no filler or metal is showing, then you are ready to unmask.

5. Using a smaller block, sand harder to get areas and all edges.

6. Using a DA, inter-surfacer pad, and 500-grit sandpaper, sand over the surface where sealer and paint will be applied.

Now you're ready for final prep and masking for paint.