| West Wight Potter Owner's Association Technical Articles __________________________________________________________________ __________________________________________________________________ |
Gel Coat Repair Instructions
Laminating is the term used to describe building a fiberglass part. The mold is first sprayed with Gel Coat then the fiberglass is put in with layers (or laminate) building up to the designed thickness or strength of the piece. This outside layer which provides the color of the boat, the Gel Coat, provides only a cosmetic appearance and does not contribute to the structural integrity of the boat. These instructions provide repair steps for the Gel Coat layer only and were written with the intention of providing the user guidance to fix any dings or scratches and thus improve the appearance of the West Wight Potter Sailboat.
The following series of instructions takes you through the procedure of a small Gel Coat repair.
Please read these instructions thoroughly before starting the repair.
1. Cleaning the Void
The first step for the Gel Coat repair is to clean and sand the void before working with any Gel Coat.
1) Before taking any action, protect the surrounding area from acetone, Gel Coat, and any other substance that could become a problem later by masking off or cover areas that may get spills or overspray on them in order to save time on the cleanup.
2) Sand the area lightly with 280 grit paper to clean out any loose particles and remember that sometimes when you start a repair, the void may run a little or a lot larger than what actually shows.
3) After sanding the void area, clean the void with acetone to remove any particles and moisture left in the Void.
Now the area is ready for the addition of Gel Coat.
2. Preparing the Gel Coat
For mixing Gel Coats we use waxed paper cups, or alternatively an empty and clean butter tub or empty and clean cut off plastic bottles will substitute.
Warning #1 - Please note that one must never mix Gel Coat and Resin in Styrofoam because
Styrofoam will disintegrate.The amount of Gel Coat required will vary according to the size of the void and the Gel Coat repair kit furnished will contain far too much Gel Coat for any one repair. The repair kit furnished contains the Gel Coat and the Hardener and these should be mixed in the following ratio:
Apply three to four drops of hardener for every two tablespoons of Gel Coat.
Using less hardener will lengthen the drying time for the Gel Coat repair but adding too much hardener will cause the Gel Coat to boil and therefore if you are in doubt, use less hardener. Once mixed in the above ratio, the Gel Coat will remain liquid for between 0.5 - 2 hours, depending on the temperature, until it hardens into a solid.
3. Filling the Void
The void can be filled in two ways, via the aerosol spray can or working the Gel Coat in by hand.
1) Aerosol Spray Application
Fill the empty glass jar the Gel Coat/Hardener Mix and then attach the aerosol can to the top of the jar and seal it tight. Then the Gel Coat is ready to be sprayed onto the void.
2) Hand Application
It is important to work the mixture into the entire void a little at a time so as to build it from the bottom up rather than just blob it on top and take a chance at creating small bubbles within the repair. For this you can use the small artist brush provided or a popsicle stick or another disposable item. Once filled, the Gel Coat must dry between 4 – 5 hours depending upon the temperature before moving onto the next step.
4. Sanding the Repair
1) Wipe the area with acetone after the repair is completely dried, which removes the tackiness so as not to plug up the sandpaper.
Warning #2 - Care should be taken not to sand any more than is absolutely necessary or you may sand through the surrounding area.
Warning #3 - Be careful not to dig with the sandpaper. Take nice, easy, even strokes with not so much pressure as to bind or stop the stroke.
2) Begin sanding with 280 grit paper to remove the excess Gel Coat. Often, we use a small wooden block with rounded edges to improve the sanding effort and please note that rubber blocks tend to follow the surface and therefore can produce a wavy surface when you are actually trying to shape something.
3) Move to 500 grit paper and finally 1000 grit paper to carefully sand the area until the surface becomes smooth and flush with the surrounding area. Be sure to increase the size of the area each time so as to remove the scratches at the edges of the repair.
Buffing the Repair
All that remains now is to buff out the repair area. We provided rubbing compound from the factory which can be used by hand or machine to polish the repair area.
Gel Coat Repair Kit Packing List