How to Repair a Pin Hole in Fiberglass Boats

Written by steve smith
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Repair a Pin Hole in Fiberglass Boats
Repair a fibreglass hull pin hole with gel coat. (boat image by pearlguy from

Fibreglass boats are often damaged by things you cannot see. Sometimes the surface of the fibreglass boat bubbles and blisters. When this blister pops, much like a blister on your hand, it causes a pin hole in the boat's surface. These pin holes are unsightly in large or small numbers. Fortunately, a simple repair method removes them completely. It takes some skill and knowledge of gel coats to get the job done right. However, anyone with basic handyman skills can repair a pin hole.

Skill level:

Things you need

  • Sand paper, 200 grit
  • Sanding block
  • Gel coat repair kit
  • Plastic film
  • Sand paper, 400 grit

Show MoreHide


  1. 1

    Locate the pin hole on the hull and determine if there are additional pin holes surrounding it. Repair the entire area, if necessary, to make the job faster.

  2. 2

    Sand the pin hole area thoroughly with 200 grit sandpaper on a flat, hard sanding block. Remove the gel coat and paint beneath it. Do not sand below the paint. Just sand the area down far enough to remove the entire pin hole.

  3. 3

    Mix hardener with a gel coat filler following the product instructions. Mixing ratios vary and drying times differ under different atmospheric conditions. So pay close attention to the hardener as you are mixing.

  4. 4

    Scrape the paste over the sanded area with a scraper to add fill to the area. Remove the excess paste with the edge of the scraper. Draw it across the paste in one motion.

  5. 5

    Cover the patch with a layer of film. This is provided in gel coat repair kits. Any type of film will work, even plastic bags. Allow the patch to dry for 24 hours until hard.

  6. 6

    Sand down the repair to remove bumps and wrinkles in the gel coat. Use 200 grit sand paper on a flat sanding block. Then use a lighter 400 grit sand paper and wet sand the surface until you have the finish you desire.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.