With mabye twenty or so of this kind of job under my belt, mabey I can help.
First of all when you corn cob blast your under body not only do you clean out the blisters, but you also open up all of those
voids left by the manafacturer which have gotten worse depending on the age of your boat. h
Hopefully the blisters are only
the surface type.If they are in the layers of the laminate, it''s more serious, but repairable. They have to be ground out and repaired seperatly.
After blasting and sanding scrub the under body with trisodiumphosphate.
Let the boat dry for as long as posible,
weeks to months,the longer the better.
You want the bottom to be dry when you start filling blisters and voids. Fill with an epoxy thickened with cabosil. Do not us a
thickener like microboloons or anything that can absorb water. When spreading
the epoxy, take it easy, and remember that it is not easy to sand. So, fair the hull
and apply at least six coats of epoxy barrier coat. Ten would be
more like it.
Let me say, if your blister problem is more than light, this may not be the perfect solution.