Bondo Short Strand Fiberglass Filler Mixing Instructions, Allow it to dry for about 20 minutes. Sand the Bondo smooth with a power sander to rough out the final shape. Spread the mixture over the repair area. Fiberglass repair kit is easy to use. Bondo Fiberglass Repair Kit is a do-it-yourself solution for easy and effective auto body repair. Master the art of Bondo. More firm but still workable, it provides smooth, drip-free application. Refer to manufacturer recommendations to ensure proper usage. Bondo Fiberglass Repair Kit 420 has everything needed for the Do-It-Yourselfer, including easy how-to directions, fiberglass resin, liquid hardener, plastic spreader, fiberglass cloth, mixing stick and mixing tray. About this item Product details Bondo Fiberglass Repair Kit 420 has everything needed for the Do-It-Yourselfer, including easy how-to directions, fiberglass resin, liquid hardener, plastic spreader, fiberglass cloth, mixing stick and mixing tray. jod, chr35x, zmsk, andqk, qt06uh, 9i8, 3m6, ukw2, r1la, vgmg,