How to Work With Gel Coat

A kayak often needs gel coat repair if heavily used.

Gel coats are typically a mixture of polyester resin and fiberglass, or mixtures of epoxy resin and glass or carbon fibers. The gel coat is generally applied to a composite material surface, such as on aircraft and marine vessels. Gel coat is used extensively on kayaks and often needs repair. Knowing how to work with gel coat and marine vessels is a valuable skill for any kayak or boating enthusiast. It will enable you to make repairs and keep your vessel looking like new.

Things You'll Need

• Polyester resin
• Fiberglass
• Hardening agent
• Pigment (optional)
• Applicator
• Rubber gloves
• Respirator and dust mask
• Large bowl

Instructions

1. Put on your protective gloves and dust mask and respirator. Select an adequate work space with good ventilation, preferably outside.

2. Identify the type of surface treatment you need to perform. This can be an entire surface treatment or a repair or refinishing job. Read the instruction labels on your gel coat supplies for the correct portions you'll need for the job. All gel coat supplies will have different mixture ratios.

3. Pour out the portioned amount of polyester resin you'll need into a mixing bowl. Add the portioned amount of fiberglass to the resin. Mix together thoroughly.

4. Add the color pigment to your gel coat mixture---if adding color---and mix in thoroughly. Add the pigment in small portions until you have a good match to the color you're trying to achieve.

5. Mix in the hardening agent, according to the instruction time chart. The amount of hardening agent you use will dictate the time you'll be able to work with the gel coat before it starts to set.

6. Apply the gel coat evenly on the surface, using an applicator such as a plastic spreader. Use small amounts and spread evenly, working back and forth. Gel coat will shrink when it cures, so if you are filling holes or cracks you want to slightly overfill the area. Ensure that no lumpy areas or drips occur. Allow sufficient time for the gel coat to dry according to the product instructions.

Tips & Warnings

• If this is your first time working with gel coat, start off by mixing a small test amount.

• Fiberglass is an irritant and if inhaled can cause severe breathing problems or lung irritation.

• Always wear adequate protection when working with gel coat.

References

• "Sea Kayaker Magazine"; Gel Coat Repair for Mortals; Brian Day; February 2006
• Atlantic Kayak Tours: Gel Coat Repair
• "Rogue Paddler & Sail"; Repairing Gelcoat; Wes Kisting; 2003

Resources

• Read this Article in Spanish
• Fiberglass Hawaii: Gel Coat Usage
• Evercoat: Gel Coat: Basic Information
• Spray Gun Industry: How Do I Shoot Gel Coat?