I removed the gelcoat from the bottom of our Nauticat 33 with a gelplane. It had about 1000 gelcoat blisters but none had penetrated the layup.
The gelcoat was quite thick about 1/8-3/16".
The question is . . . what type of cloth should be used to build it back up using the WEST System. I want to avoid microballoons and build up the surface to the profile before planing and attempt to produce an impermeable surface.