Fiberglass adhesive fill & finish can be used as a filler on fiberglass panels, smc, aluminum, galvanized steel, steel, concrete, wood and masonry. It can also be used as a light duty bonding adhesive for non-structural repairs such as fiberglass backing repair strips. Product Features:Maximum application versatilityFor low-stress filling & bondingFor repairing minor holes, cuts & gouges in fiberglass, SMC, aluminum, galvanized steel, steel, concrete, wood & masonry.