How to Repair PVC With Fiberglass

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Fiberglass is commonly used for repairs or reinforcement on materials such as plastics, wood, metal, and even plastic foam. Fiberglass will bond to almost any surface as long as the surface is properly prepared and scuffed. For repairs on PVC, fiberglass works great and if applied properly will likely last as long as the PVC does.


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Fiberglass is applied in layers of dry fiberglass mat that's saturated with resin, which is a very thick liquid that requires a catalyst in order to harden. You can find fiberglass repair kits with the mat, resin, and catalyst or hardener online or at a local auto parts supply store.

Things You'll Need

How to Repair PVC With Fiberglass

Step 1: Grind Around the Damaged Area

Put on safety glasses and grind the rough edges of the damaged PVC smooth using a die grinder. If there is a deep fracture, grind the damaged PVC out of the middle of the crack and gradually taper the edges. Lightly grind 6 inches all the way around the damage, being careful not to go deep into the PVC.


Step 2: Clean the Damaged Area

Wipe the damaged area clean using a rag and acetone.

Step 3: Cut the Fiberglass Mat

Use a razor knife to cut three layers of fiberglass mat that completely covers the damage. Make each layer 1/4 inch smaller than the last so the edges of the repair are tapered and not ledges.

Step 4: Mix the Resin With the Catalyst

Follow the product instructions for the amounts of fiberglass resin and catalyst to use and mix in a small bucket. Use a wooden stir stick to thoroughly mix the catalyst with thee resin.


Step 5: Apply the Resin to the Repair Surface

Wet out the surface of the repair with the resin using a 4-inch felt roller. Apply the smallest layer of mat first, with the damage directly in the center of the mat.

Step 6: Saturate the Mats and Let the Fiberglass Cure

Saturate the mat with the felt roller and roll out any air bubbles using an air roller. Apply the next two layers following the same process and let the fiberglass cure until it's hard and cool to the touch.

Step 7: Sand the Patch

Sand the fiberglass patch with 100-grit sandpaper to remove any burs or sharp hairs of fiberglass.


When using a grinder, you should always wear eye protection.