Repairing / repainting fibreglass kayak

I bought a 2002 Current Designs Slipsteam last year that’s in great condition, but I beat it up on some coral over the winter and it’s now got a few more cracks and chips than is ideal.

The fibreglass is still structurally sound as far as I can tell without sanding all the paint away, but it is exposed in places, and others have cracks in the paint. I covered exposed areas with nail varnish whilst away, as that was all that was available in central america!, but it’s time for a proper repair now I’m back.

I know nothing about paint types! I don’t live near any large marine supply stores and don’t want to travel to the city right now. Any suggestions for paint available from a hardware store (Home Depot Canada) that will do the job? What layers are needed - base, main paint and some kind of top coat? I looked at ordering gel coat online but it seems really expensive and I don’t think the hardener can be shipped?

Should I be looking at sanding down the whole base of the boat and repainting it all, or just the areas of damage? (they’re all small, but there’s probably 20 areas missing paint or with cracks). The paint is discoloured and probably getting kind of old now, so wondering if it’s worth doing all of it - but then I’d be sad to take the decals off!!

Thanks for any advice.

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Fiberglass kayaks don’t have paint on them – it’s a 2-part epoxy called “Gelcoat”. It’s easy to fix – sand lightly only at the crack, and widen it on the surface just a little, mix up the gelcoat and add some pigment of the color of the area you’re fixing to it. Take that, and dab it into the crack until it’s full. Sand it with the finest sandpaper you have the next day, and buff it. Done.

You can get this stuff at any marine store. They’ll be happy to help you get the right pigment, and the gelcoat kit.

And if you think the fiberglass might be slightly damaged, epoxy a strip of fiberglass tape on the inside of the hull over the area you’re concerned about. Both repairs are easy.


Two things I will add to Wayne’s excellent advice. 1. Allow the fibreglass to dry really well, really well. Store it indoors for a couple weeks, use desiccant or other drying agent encapsulated in a bubble in the affected area, or some other way of sucking out any moisture. Any moisture trapped in the fibres will cause that area to be soft. 2. Online gelcoat & hardener can be shipped in the small quantities you will need. How do I know? In January I had to order special gel coat & hardener from for an NDK Explorer repair job. Yes, quality gel coat can be expensive.

Good luck! Also, spraying the gel coat makes for a professional finish if that is a concern.

First of all, doing a proper gel coat repair is not quite that simple. You will need to read, or watch a really good video explanation of how to proceed. You will also need quite a list of things to do a good job.

Number one is that you will need a temperature of at least 65, or 70 degrees Fahrenheit to work in. You will need Acetone and lots of different grades of sandpaper. The sandpaper needs to be wet/dry. Most of the sanding after the application of gel coat will be wet sanding with water. You will need tape–I use black plastic tape, because it works better for me than masking tape. The tape is for two steps in the operation. 1) To cover and protect areas around the damaged surface that you do not want to scratch up. 2) After applying the gel coat, it needs to be covered with waxed paper and sealed with the tape while it hardens. I usually let it set over night, but the gel coat usually sets up in a couple of hours. Covering the gel coat application can be skipped if you use a waxed version of gel coat.

Without going into all the fine details of working the gel coat after it sets up, there is a tool that really comes in handy and that is a variable speed random orbit sander/polisher. I would highly recommend the Chicago Electric, or Bauer 6" from Harbor Freight. And don’t forget the polishing pad.

Most of the preliminary sanding will be done by hand–before and after the gel coat application. When applying the gel coat, don’t worry too much about smoothing it out and it must be proud of the surrounding area. It does shrink as it cures, so sometimes you will need to make a second application.

I don’t mean to in any way discourage you from doing these repairs as it really isn’t that complicated and it is very gratifying when you do it right.

Don’t worry about getting an expensive polishing compound–Turtle Wax polishing compound works just fine.

While you’re at Harbor Freight, you might as well check out their sandpaper. You will need a nice selection between 400 and 1500 grit wet/dry. I even keep some 2000 around. Remember to wipe the repair area with Acetone just prior to applying the gel coat.


As long as the glass fiber layers aren’t damaged the repair you need to do is completely cosmetic. so there are two ways you can repair it. Method A by wayne smith and kayak hawk is just fine. I second making sure the area to be repaired is absolutely dried out. Methond B by Magooch is fine if you are really concerned about how the boat looks. My water craft get surfed over rocks and sand and mussels and god knows what else. Doing a classy repair job just doesn’t make sense because the bottom will be scratched up and dinged again soon. You can go full on Ghetto-Seadart and make sure the area is dry, sand rough spots carefully, clean it off with water then alcohol or acetone, and then mix up some good quality epoxy with some spray paint or modeling enamel to match the color as close as you can, and smooth it on the area, cover with plastic wrap until dry, and then sand smooth with very fine grit wet sand paper. Or you can go full on ghetto, and just give it a hot epoxy coat, and then rattle can spray on the paint after everything is dried out. If you think it’s likely you are going to ding the boat up again I would go with the last method. Nobody will care unless you want to sell it to someone like Magooch. Then you best do a class repair.

Actually, on my Caribou (which I’ve had since the mid-90’s), I’ve gone a little “Rat Rod” on the repairs if they’re below the waterline. I do a nice repair on the gelcoat, but I put zero pigment in it if the gouge is down to the glass. When the boat is sitting on the car in the sun, it looks like it has holes in it. There’s probably a half dozen of them. Makes people think twice about paddling with me…. :laughing:

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A pint (250ml) can of gelcoat is not particularly expensive. The catalyst for it (MEKP) is used for a variety of fiberglass repair materials and readily available in places like Home Depot, auto parts stores and of course, marine suppliers.

Gelcoat is not epoxy, it’s polyester resin. You can repair it with epoxy, but you’ll have a hard time getting a good color match on a white hull, since most epoxy is a light amber color and tints won’t disguise it completely unless you use way too much tint, and weaken the epoxy in the process.

Although gelcoat will absorb a small amount of moisture, fiberglass does not (it’s glass) and the polyester or vinylester resin used in the laminate won’t absorb much either. Moisture absorption by the resin or gelcoat is only an issue for boats that are stored on the water. Simply paddling for a few hours is not going to cause a problem, though of course you want the surface to be dry before you work on it. A quality fiberglass laminate has no voids and the fibers are completely encapsulated, so the only way to get significant moisture into it is if it’s damaged, in which case you’re looking at more than a cosmetic repair.

Laminating gelcoat will only cure in the absence of oxygen, so you either have to cover it or mix in a wax additive that will migrate to the surface and seal it, allowing it to cure. A better bet is to buy finish gelcoat, which already has the wax added. My personal preference is finish gelcoat paste, which is thick enough that it won’t run, even when applied to a vertical surface. It works a lot better than liquid gelcoat when you’re working on keels and curved hull surfaces. It’s supposed to be a bit stronger than liquid gelcoat, but I don’t know if the difference is actually significant.

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I have not checked their website put Interlux puts out a good info book you can pickup at marine stores. I’d check the site. There are a couple of popular brands of marine epoxy resign like West Systems. In a pinch you could use something like JB Weld e r . But for bigger, deeper spots you are going to want to thicken it as stated in another post so that it doesn’t just run all over. Note that usually dries quickly and gets really hot after mixed.

Working with gel coat is harder than it sounds. When I repair fiberglass canoes and kayaks, I rough up the surface a little and paint them.