How to Repair Fiberglass Delamination

By Jay Kurz

Fiberglass is usually applied using a lamination process. This process involves layering fiberglass mats. The amount of layers determines the thickness of your finished laminate. For example, if you're using the standard 1.5-ounce matting, seven layers equals 1/4-inch thickness. Delamination is when the layers of fiberglass begin to separate. The cause of delamination can be anything from old age to cheap materials. This is a common problem with fiberglass and can be fixed the majority of the time.

Things You'll Need

  • Penny
  • Standard drill
  • 1/8-inch drill bit
  • Syringe
  • Resin
  • Hardener
  • Small bucket
  • Stir stick
  • Acetone
  • Rag
  • 10-pound weight
  • Mylar (polyester film)
  • Grinder
  • Respirator
  • Safety glasses
  • Masking tape

Step 1

Determine how large the area of delamination is. You can do this by using a penny and tapping on the fiberglass. It will sound hollow in the affected areas.

Step 2

Drill holes every two inches or so on the delaminated area. Be careful not to penetrate the layers directly underneath the delamination. To assure you do not go to deep you can wrap your drill bit with masking tape only leaving a ¼ inch or so of the tip of the bit showing.

Step 3

Mix the resin and hardener in your bucket as directed on the labels. Stir until thoroughly mixed. Fill your syringe with the resin mixture.

Step 4

Insert the syringe into one of the holes you drilled and inject the resin until it starts to overflow. Repeat this step on all of the holes until the delamination is completely filled with resin.

Step 5

Wipe any excess resin from around the holes with a rag and acetone. Only get the rag damp to avoid any acetone getting into the holes.

Step 6

Cover the entire repair with Mylar and place a weight on top of the Mylar. This will ensure the resin fills all voids. Let cure for one to two hours or until the resin is hard.

Step 7

Remove the weight and Mylar. While wearing your respirator, grind the excess resin down to a smooth surface.

Tips & Warnings

  • If you need to speed up the curing time you can use a blow dryer or some other source of heat.
  • When working with fiberglass always wear safety glasses and a respirator.