Has to be epoxy.
Polyester resin will eat the foam.
actually the mekp eats the foam (stryfoam derivatives)
dont have to worry about it with polyurethane foams and pvc foams.
JUST BE WARNED home depot pink foam has NO density to it and will provide no structural support nor is its sheer and peel strenght worth a shit
No, the foil stays. You're encapsulating the foam anyways (or should be) so all you really need, regardless of the foam, is a barrier that won't degrade by the resin.
The Celotex board you use (the pic you posted)......do you use it for "structural pieces" in lieu of say Divinycell H80 or Nidacore?
Can you use this product for longitudinal or transverse stringers for deck support? etc.
Forward cabin pieces for upright walls of an enclosed head?, vberths?
Explain where you use this stuff when building a boat.
Also, any pics of you "foam spray" radius edges ??