Fix a Very Broken Surf Board

Step 2 Heat Gun and Rag to Remove More Wax

Use a heat gun and clean rag to remove more wax. You'll see the wax sheet out in front of the heat gun when it melts. You can feel when most of the wax is gone, because the rag will slide much more easily over the board.
Then soak a new clean rag with isopropyl alcohol and rub down the board to remove any remaining traces of wax. Wax would prevent the new fiberglass from sticking properly