How to repair fiber glass cracks in Cars

Many auto parts are made of fiberglass, and it is common for fiberglass parts to crack. How to take your vehicle to a body shop to have a simple repaired fiberglass crack can cost a lot of money. Fortunately, you can repair cracks in your car’s fiberglass yourself at a lower cost.


  • Wash the crack with mild soap and water. Rinse and dry completely.
  • Insert a little cone-shaped tip with a slightly wider than the crack in your Dermal. Use the tip of the bit to widen the crack slightly, making sure that the entire crack is exposed. Wipe the area with a damp cloth and dry thoroughly.
  • Use the plastic diffusion tool to completely fill the expanded crack with fiberglass epoxy resin. Keep the resin fairly level with the car body, but make sure the crack is fully filled. Allow the resin to dry for a minimum of 4 hours or according to the manufacturer’s instructions.
  • Sand the soft epoxy with the body of the car with its wet 240 grain paper. Sand until the area feels soft to the touch.
  • Sand, once again lightly with 400 grit wet paper until the area feels completely smooth.

Tips and warnings

  • Apply fiberglass epoxy in a well-ventilated area and do not breathe fumes.