Quote:
It forms a water-resistant outer skin when cured.
As any sailor will tell you - "water resistant" does not equal "water proof"
Also, with any expanding sealant, unless you are
very careful, the foam will expand beyond the voids and start to distort the structure. Great Stuff can apply incredible force when contained - I've seen it bend door jambs and push bricks out.
For some reason, it is hard to get through to people that when hulls/decks delaminate,
it's not the foam or the laminate at fault.
It's the bond between the the layers that's failed. The only was to truly restore that bond is with a chemical adhesive - epoxy.
Shooting foam into the void just adds another, weaker layer to the mess.