Using Gelcoat for Boat Repair - 10 Simple Steps

October 19, 2022 3 min read

Using Gelcoat for Boat Repair - 10 Simple Steps - TRUE COMPOSITES

Are you a DIYer who is looking to fix up your boat? Applying gelcoat may be the project for you! In this blog post, we will walk you through the 10 steps necessary to apply gelcoat to your boat. We'll also provide some tips to make the job go smoothly. So, whether you're a beginner or experienced DIYer, read on for all the information you need to get started.

What is Gelcoat?

Gel coat is the outermost structural layer on a fiberglass hull. It's designed to protect underlying materials like epoxy or polyester resin which produces an excellent finish over composite substances such as those made from plastic or glass fibers in our case; it also prevents water intrusion through cracks along with protecting against UV rays--so basically this stuff will keep your boat looking good while still keeping everything dry!

Be Prepared 

Whether you're doing some minor touch-ups or a full repaint, being prepared with the right tools will help make sure that everything goes smoothly. Make sure to prep ahead of time and take advantage from having all your supplies on hand at home!

  • Pressure Spray Hose
  • Bucket
  • Boat Fiberglass Cleaning Solution (detailing product)
  • Acetone Solution
  • Masking or Painter’s Tape
  • Microfiber Cloth
  • Large Rags or Sponges
  • Disposable Gloves
  • Safety Glasses
  • Disposable Mask
  • Paint Brush
  • Spray Coat Applicator
  • Fine Grain Sandpaper
  • Sealant
  • Gel Coat Paste
  • Plastic Film or Wax Paper
  • Spray or Liquid Gel Coat (clear or colored)
  • Fiberglass Filler
  • Fiberglass Hardener
  • Rubbing Compound
  • Buffing Machine
  • Polish
  • Wax

Prep Your Boat

Wipe your boat dry after washing it with the proper cleaning products. Gelcoat will not stick well if there's still residue on your boat, so make sure you rinse thoroughly and wipe away any excess water before drying off completely!

Identify All Areas that need to be repaired 

Marking all the identified cracks, scratches and chips will help you to work more efficiently. Use masking tape or painter's putty for this purpose!

Sand the damaged areas

Once you’ve identified the damaged area, clean it again. Then wet sand with a medium-grit paper to remove any paint that may be on top of your boat's gel coat and prevent further damage from occurring in this area--make sure not too overdo it!

Apply Gelcoat Paste

Match the color Gelcoat Paste to the color of the hull applying. This may entail some testing to get the right gel coat color. Once you’ve got the right color, fill the sanded down crack with a pigmented gel coat paste using a putty knife. Check that there are no air bubbles. Let the gel coat stand to cure it completely. Cover the treated area with plastic film or wax paper.

Allow the area to dry 

Do not rush. If necessary, you may need to sand the area once again. Apply another layer of gel coat paste to make it durable. Allow enough time to dry out the area. Cover it again with plastic film.

Repair worn out gelcoat

Fiberglass cleaner will restore the shine and take out any dirt. If you need to sand more, do so until it's as smooth as can be! Fill in cracks with a mixture of Fiberglass Filler & Hardener that blend well together for an even application.

Fix old gelcoat, if necessary. 

Timing is key to this step. Attending this should be done early enough so as not incur high repair costs and smooth out any cracks with a fine grit sandpaper, removing the old gel coat if necessary before applying new one in layers according-to how thick you want it - apply as many layers of gel coat as necessary.

Polish the gelcoat

If you need to, use a rubber compound before polishing. This will smooth out any dull surfaces and keep your boat's exterior clean!


Waxing your boat protects it from UV rays, water impurities and minerals that can damage the finish. It also enhances depth of shine as well as luster by adding protective layer over top paint job protecting it against anything harmful like dirt particles or bugs splashing up while you're out enjoying boating! 

View our gelcoat products here