Skullptura
Member
When you use spray adhesive and then glue down the fiberglass cloth /mat the the inside of the piece and then put your resin on it it causes issues. No matter how careful you are, air pockets develop and it may not adhere to the edges well either over time.
I would just like to point out that the reaction of the resin dissolving the spray on adhesive causes small amounts of vapours to be released, resulting in the bubbles appearing. I had to research that answer lol. But I hope it helps clear up why it happens.