I have filled some bow rail holes with resin and applied gelcoat to the thickness of 2 pcs of tape above the surface. Can I start with something faster cutting like 400 or am I risking cutting into the surrounding area too much? Off course I will be using a stiff sanding pad, but maybe I should use an even stiffer block? I'm assuming that I finish up with 1200 then 2000 and finally compound. Thanks for the help now and in the past!