Gelcoat is a liquid that hardens to form a thick layer that’s used to protect fiberglass and give it a shiny, smooth finish.

Applying gelcoat to fiberglass is simple if you have the right tools and take care to mix your gelcoat properly.

In this article, Aaron from Pause4Life speaks about how he repaired his boat using fiberglass gelcoat kit.

Pros of Using Gelcoat Kit

  • Easy to use
  • Visually pleasing
  • Protects well
  • Weather proof
  • Easy to use
  • Many colors possible

Cons of Using Gelcoat Kit

  • Mylar film included was smaller than needed
  • Difficult to use
  • Hard to get smooth
  • Messy
  • Matching color to boat

Tools Needed

  • West Marine gelcoat repair kit
  • A small cup
  • Acetone
  • Tape
  • Turtle wax rubbing compound
  • Turtle polishing compound
  • 80 grit sandpaper
  • Epoxy resin

I had a little bit of a mishap this weekend and the boat slammed into the dock and I got a little damage to my gelcoat here, so I’m going to try to repair that. I’ve never done this before, but I thought you can tag along and see how I’d do it and if it turns out great, then great. If not, then we all learn a lesson together.

So here’s what we got and I assume you can see that (in the image above). So I’ve taped off this. It’s scratched here. I don’t really know if that’s going to buff out or not, but after the repair’s done, then I’ll come in and I’ll try to fix that scratch. But we can clearly see the fiberglass there and we’ll try to repair this.

Repairng the Boat’s Fiberglass Area

So, what do we have? Let’s get some supplies here. So for starters, we’ve got acetone and a rag to clean it up. Obviously the masking tape, which would be used to mask off the area and then we got some sand paper.

So I bought a kit from my local boat store, we’ll just say that it rhymes with Best Latrine. So I think it was about 40 bucks for this kit. The kit came with no-run polyester gel paste, some tinting agents, hardening agents, spreading sticks and some instructions. I took a paper cup and I am going to mix in this. The idea is to try to tint it to match. I’m going to go with just white. I don’t know if this is white or off white or what, but I don’t think that there’s anyway in the world that I could actually match this color. So I’m not really going to even attempt that.

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So first we’re going to clean the area off real well with acetone and then we’re going to mix up the gel and some white. I don’t know what color this is, I guess it’s clear. I’m not sure but whatever’s in here we’re going to add some white to it, get it white, add the hardener and then apply it and let it set up. It also comes with a piece of film that you’re supposed to lay over it.

This is right on kind of a double corner. I don’t know how that’s gonna work but I think it’s supposed to make it nice and smooth. But I don’t think I’m going to be able to really achieve that. So I’m going to have to sand it and buffet and sand it and buffet it, once it’s cured. So we’ll see how that goes. Let’s get started.

Okay, so the gel is a kind of pinkish color, smells like mondo. Start with that. See what happens. I think is going to be just fine. I think it will be noticeable.

It’s much harder now. Working this in as best I can.  Well, I was supposed to take this thing and work out the air bubbles. That works really well. I am just going to tape it. 

Okay, so we’ve put this on here just to shade it a little bit. It’s been a hour and a half or so and it said it takes about an hour to cure. So let’s see what we got. I think it’s cured.

It seems to be adhering to that part, I guess I got a problem. Well, it’s coming up slowly (by sanding the area). We’ll apply a little bit of rubbing compound. Now a little bit of polishing compound.

Well it’s not awful, I’ll work on it some more. You can see it, but a little bit of heavy scratches down here. Obviously you can see the discoloration right in here. There are two pin holes from the air bubbles that was in the gel paste. But overall I think that’s good. That’s not too bad. It looks a lot better than it did.

So I just used a turtle wax rubbing compound first and then turtle polishing compound. It’s just what I had laying around. You could probably use a wet sand finer grit sandpaper and it might come out a little bit better, but I don’t have any finer sandpaper. But overall turned out pretty good. It’s not the greatest job in the world, but satisfactory for this little project. It’ll help me with maybe future projects. So hope you guys found this helpful.

Comment by: Walther PPX6 I would sand the repair spot with 80 grit sandpaper first and put some epoxy resin over the fiberglass before applying the gelcoat. I used the same West Marine kit with the mylar film on my Sunfish and it only lasted a year before cracking and chipping out. I hope it lasted longer for you than it did for me. I”m going to re-do the repairs right by sanding out the previous repair spots and using several built up and sanded coats of Evercoat white one step gelcoat over epoxy resin.