How to repair cracks in hard plastic

Updated February 21, 2017

Plastic is a popular material for a variety of commercial goods. From garbage cans to prosthetic limbs, children's toys to car bumpers, the resilience and sturdiness of plastic makes it an extremely versatile substance. As strong as hard plastic can be, it is not resistant to cracking. If left in cold weather or under ultraviolet rays for extended periods of time plastic can become brittle and weaken substantially, resulting in cracking or chipping. However, repairing this damage is easy with the right materials.

Place several strips of masking tape on one side of the cracked object. This will prevent the plastic epoxy from seeping, and hold it in place while curing.

Squeeze a bead of plastic epoxy into the crack. The amount of epoxy you use should be relative to the size of the crack.

Pack the epoxy into the crack with a spreader tool. Ensure that every nook of the crack is covered. Smooth the epoxy so no edge is detectable.

Allow the epoxy to cure and dry for at least eight hours.

Sand the repaired area with fine-grit sandpaper, making the fix look as smooth as possible. Remove the masking tape from the back of the object.

Apply paint to the area if desired. Choose a colour that closely matches the rest of the plastic to conceal the repair.


You may wish to clean or pre-sand the area for better epoxy adhesion. Use lacquer thinner or a general solvent.


Avoid getting any epoxy on your hands. The chemicals may be harmful to your skin.

Things You'll Need

  • Masking tape
  • Plastic epoxy
  • Spreader tool
  • Fine-grit sandpaper
  • Plastic paint (optional)
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About the Author

Brandon Getty began writing professionally in 2008, with columns appearing in "Thrasher" magazine. He received a Bachelor of Arts in literature from the University of California, Santa Cruz, and lives in Stockton, Calif.