I'm mixing up resin and Q-Cel. This is forming a kind of paste, and when it cures, it forms a chemical bond between that flap of fiberglass and the foam core of the surfboard. So I'm applying this ...
This radically changed the way surfboards were made as Balsa wood gave way to PU foam and fiberglass and the rest ... styrene foams and carcinogenic resins that unfortunately dominate the surf ...