drnebe said..
When you say “seal foams” are you saying a thin layer in the cavity before the first layer of fiberglass? If so do I wait for that first layer to cure before the glass? Also do I need to chase these cracks in the eps or could I start filling now?
There is many way to do this repair. As Mark said best way, pro way, is to build a sandwich with same materials. But if you want to do it with what you have: do a cream resin qcell mix, seal the eps and pvc with this, thin layer, let it set a little, when no more runny but still soft and tacky lay fiberglass over and lam it. Again when still tacky fill cavity with a resin qcell "dry mix", lot of qcell so mix is like a thick past, push it in hole with fingers, impossible to spread. Let cure, sand flat, lam over and finish. The thick, syntactic foam mix will work like a core.
