How to Fix a Fiberglass Boat Deck

When you need to repair the fiberglass deck of a boat, you can do the work yourself, with little ado. Deck repairs differ from other hull repairs in that you're unlikely to damage the boat's foam flotation, which is usually found below the hull-deck joint of fiberglass boats. Once you establish where the edges of the damage lie, you can move through the process of applying the layers of fiberglass and complete the repair.

Things You'll Need

  • Plastic hammer
  • Cloth
  • Acetone
  • Reciprocating saw
  • Disk grinder
  • Coarse sanding disk
  • Paste wax
  • Marine epoxy kit
  • Fiberglass mat
  • Fiberglass cloth
  • Cardboard
  • Tape
  • 420-grit sanding blocks
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Instructions

    • 1

      Tap the deck with a plastic hammer around the damaged area to locate the extent of the damage.

    • 2

      Remove wax from the damaged area by wiping it with a cloth dipped in acetone. Cut out the damaged deck with a reciprocating saw.

    • 3

      Grind around the hole you've made with a disk grinder and a coarse sanding disk. Grind back from the hole to create a shallow pit leading to the hole.

    • 4

      Apply paste wax around the ground area. Mix up marine epoxy, according to the directions on the epoxy kit. While you're waiting for the epoxy to start thickening, cut two pieces of fiberglass mat and two of fiberglass cloth, starting with a small piece of mat to fill the hole, then a larger cloth, then a mat larger still and a larger cloth. Tape a piece of cardboard over the hole from below.

    • 5

      Apply epoxy from to the deck from above. Follow this with the smallest fiberglass mat. Press the mat into the epoxy. Apply more epoxy and the smallest fiberglass cloth. Apply more epoxy and the larger mat, followed by more epoxy and the larger cloth.

    • 6

      Press the mat or cloth into the epoxy with each application. The repair is now 1/8-inch thick. Allow it to harden and repeat the process until the repair is slightly higher than deck level. Sand it down with 420-grit sanding blocks and finish it as you please.