bottom paint removal -best electric vacum sander?

[pelican]

If there is "no damage" to the gelcoat, Why the barrier coating?

Hmmm, maybe not so false?

gelcoat is polyester based-it's not waterproof,barrier coat,it's epoxy based,it's waterproof...the idea of a barrier coat is just what it states "barrier coat"...ever see a boat's hull with osmotic blisters ? this is water passing through the gel coat...
after blasting,the gel coat is left with a "profile"...i've had boats,a 24 proline for example,the bottom paint was way high-after the blasting process,that area where the bottom paint was,i sanded,followed by wet sanding,and buffing with rubbing compound-the areas were brought back to a shine...

there's alot of misinformation about blasting bottom paint-one gentleman before made the claim "it disturbs the matrix of the fiberglass"...truth is,it's one of the safest,easiest ways to remove antifouling paint...
in the offseason,a few months from now,there's gonna be a few boats at my shop to be blasted and barrier coated,followed by ablative antifouling paint,you're more than welcomed to come and see them...