Bondo 32-fl oz Color-changing, Heavy Duty, Waterproof Interior/Exterior Brown Fiberglass Resin Repair in the Patching & Spackling Compound department at Lowes.com
3M 20124 All Purpose Fiberglass Resin, 1 Gallon - Walmart.com
Fiberglass Supply Depot Inc. > Polyester Resins > Isophthalic resin