Repairing a 17' bass boat, the hull was completely compromised and had to remove floor, stringers, and bottom coring. When I replaced the bottom coring I used 3/8 thick balsa core that was cut in one inch squares and held together with scrim. I used 1.5 mat wetted out slow cure mix and layed the coring on, then used packs of roofing shingles to hold down until resin cured. I seem to have a good bond to the hull with the coring. My question is should the coring be sealed up before I laminate over the new coring. I did a small section in the front and it seemed to take excessive resin to fill up all the voids in the coring squares and the coring itself. Did I use the wrong coring material with the squares? I was thinking of using a cabosil mix peanut butter consistency to seal the coring before lamination, or is it normal to fill all the voids with resin. Using resin seems heavy and weak to me.

I would do a hot coat of resin over the core to seal it up, then do your finish laminate.

Would a hot resin mix applied with a roller work? That should provide enough to seal but not fill up the voids. Then start laminate next day.

I Would fill the voids with resin. Otherwise your voids between balsa will be like a void in the laminate. Every balsa core Ive ever ground was filled with resin. You could have used Coosa for your core.
That's some gooood S--t!

I think using the flex style balsa cut into squares was my mistake. Regular coring would not have needed so much resin. Next time I'll know.