Seacraft Penske delamination

[JamesW]

Attached are some pictures of the cockpit sole of a seacraft 23 that was
recently rebiult using penske board with a fiberglass laminate. You'll notice
that after it was primed large blisters started to appear. When the blisters
were cut out you could see that a thin layer of the penske board was still
adhering to it. Anyone ever come across this problem?