How many coats of clear gelcoat should I brush into a mould before I start to laminate? I will be brushing as I don’t have a gelcoat gun. I was planning on two coats , if so should I let the first coat completely dry or just wait till its tacky before applying second coat?
Thanks
Ray
try to obtain a thickness of about 15-20 mils, you can get a mil gauge from any fiberglass supplier.
You can get that thickness with one coat but it won’t be pretty using a brush. The problem with using a brush is thin spots. Once you start laminating you run the risk of alligatoring
Try a thin coat in one direction, let it “B” stage and then another coat 90 degrees from the first. But the secret is getting the MEKP % the same…
When I’ve brushed gel coat (I don’t have a gun either), I just figure out how much gel coat I need to mix based on the surface area of the mold to give me about 15 mils. I then mix it up in about 1/2 quart batches, catalyzing at the same rate, and brush it all at once. I’ve found that it works best to brush from the center to the edges, and to feather the beginning and end of the brush stroke. It is very hard to get it even though. I do get thin spots, but fortunately haven’t had the gel coat alligator on me yet.
Since you’re brushing clear gel coat, I’m sure this will be more difficult to see the thick/thin areas. I’ve only brushed white gel against an orange mold.