Ideal for large hole repair, rust out areas, rebuilding missing pieces, shattered fiberglass, and more. Versatile filler works with fiberglass, metal and wood. Fast curing formula is sandable in 30 minutes for quick repairs. Two-part formula chemically bonds and adheres faster to hard-to-stick-to surfaces. Finish project with a layer of Bondo Original Filler or Bondo Fast Dry Filler for a smooth, professional finish. Top coat of Bondo Glazing and Spot Putty is recommended to fill pin holes and small imperfections for a smooth finish.