Step 2) Sanding
Take the sand paper and sand enough to rough up the surface. It’s unnecessary to remove more than 1/32” of material, sanding will allow the primer and paint to adhere in cracks as well as surface to give a longer life. Any all-purpose sand paper between 80 and 120 grits will be enough to rough up the surface but not damage it.
Step 3) Cleaning
Again, using acetone, clean the surface for any debris and shavings left over from sanding. Ensure the surface is dry before proceeding.