Blistering blues

[WillyC]

So now that the boat has been flipped and all the bottom paint removed there is 30+ years of nicks and scrapes to fix. It seems in the past all that was ever done was just to recoat with bottom paint. There are many many small pimple type blisters that I ground out with the drimel tool. Unfortunately thare are maybe 20 or 30 larger blisters (about the size of a quarter) that are blisters below the mat that will be much more intensive to repair.
Pimple blister and nicks and scrapes.




Larger blisters that will have to be ground out. Quarters for scale.

Deep delamination and close up.


Ground out larger blister (still needs a little more grinding)


A couple of questions. Since I am planning on spraying the bottom with gell coat, what is the best product to fill the small pimple type blisters with. I am thinking the 3M high strength repair filler (vinylester based). I would like to use the system 3 quick fair (epoxy based) that I already have but am unsure of the compatability with the gellcoat that will be going on top of it. Anybody have any good reccomendations.

I'm also wondering if I'm doing more damage than good by grinding out the larger blisters. On the surface, there's no apparant damage but below the mat and fairly deep into the glass there is delamination. I wonder if I would be better off just leaving those larger blisters alone. What do you guys think. Thanks -will