Exceptionally strong formula can be drilled, anchored, or tapped to repair or rebuild cosmetic damage. Multi-surface use compatible with metal, fiberglass, masonry and wood for auto and home. Reinforced with aluminum, this extra strength formula is an easy-spreading filler. Two-part formula chemically bonds with surface to adhere permanently. Fast-curing formula allows for a 5 minute work time and sanding in as little as 20 minutes. Top coat of Bondo Glazing and Spot Putty is recommended to fill pin holes and small imperfections for a smooth finish.