Gel Coat Repair

I hit a submerged rock on a surf landing and lost some white gel coat on my QCC 400. There are 3 missing patches of gel coat, about 1" by 2". You can see the fiberglass but it looks undamaged. It leaks a little now, about 3 cups of water after 2 hours of paddling. What should I use to repair the damage, brand name of gel coat, and how do I do the repair? Thanks in advance.

Here are two links for repairing gelocat. I recently bought a fiberglass kayak so I found these ahead of time. I have never done it but thought this would help. Good luck.

Call Current Designs/QCC…
and buy the materials. They’ll have good advise, too.

Should not be leaking
If the leaks are from the damaged spots, then more is damaged than gelcoat. The gelcoat is really just there as a scuff it up, looks good, UV protectant layer. Don’t dispair though, glass repairs are fairly easy. Can you confirm the leak is from the damaged areas?

Instructions are on the gel coat
We get ours from West Marine, most gel repair stuff (get the gel and an additional tube of goop to mix in) has instructions for use on it. Wear a mask and/or do it outdoors. The gel is pretty nonreactive stuff, but it gets much more interesting when you add the goop.

Thanks for the info. I put the kayak up on some saw horses and poured a bucket of water in the back hatch. The water slowly leaked out the damaged areas. I talked to Steve at QCC and he says without the gel coat the boat will leak.

That is really weird
I agree with Scott. Fiberglass (or any other synthetic cloth) that has been completely impregnated with epoxy should not leak. Many composite boats are not gel coated.

I think you either have small cracks that might be difficult to appreciate, or some of the fabric has broken away from the cloth fibers. Either way, I would do more than just re-gel coat the area.

Have you tried to examine the interior of the boat at the area of damage? If you can do this and see light colored lines or light colored areas it is an indication of cracking or delamination of the fiberglass. If you have a hatch that allows you access to the interior of the boat where it is damaged, I would put a patch (fiberglass or aramid or carbon fiber) over the damaged area which will restore water tightness and strength.

If you can’t do that I would at least thoroughly sand the area of damage, clean it well and apply some epoxy over it before re-gel coating.

Dry it out
Mix up some two part epoxy, and cover the holes.

Sand smooth when the epoxy has hardened, and then spray paint with automotive paint.

It might need two coats of epoxy if the first coat doesn’t come smooth.

Be careful to not let the epoxy run or build up over the surrounding non damaged areas


I’ve seen soaked fiberglass leak
If anything, over time some seepage is the norm if the glass layer has a chance to stay wet for a while, at least in my experience. I did not have this problem on the trip home when I took a hell of a chip out of my NDK boat pulling in for the lunch break, but that boat has a custom layup with extra reinforcement all along the keel line. It is not the normal situation.

Until the last couple of years my husband and I attended a symposium each fall off of Bar Harbor, where there are many island with good shoreline for rock gardening. If we went out with a group of more aggressive paddlers, one would often get caught up on a rock shelf and be spun by waves for a while until the paddler and boat were extricated. The paddler sometimes ended up bleeding from rock cuts, the boats always got punctured to the glass layer here and there. As far as I recall, every one of the punctured spots developed a tendency to seep water, the only diff being whether it started as soon as the paddle home or if it took another day of paddling to start.

I should note that the paddle home in some cases was over two hours. That is a lot of time for water to do its thing.

Lay down in multiple layers
If it is deep, the stuff won’t dry right if the layer is too thick. Will just have to redo it in a year.

Don’t know about the auto paint though, certainly not for a white hull.

Fiberglass fibers can’t get soaked
if they are impregnated and imbedded in intact resin. That is the problem. When the fiberglass breaks away from the resin matrix, the fabric is no longer waterproof, and perhaps more importantly, it lacks strength.

In that event, I would direct my efforts to getting the fiberglass re-bedded in resin if possible, or patching over it if not. Gel coat looks nice and adds some abrasion resistance, but not a lot of strength and it cracks and spiders pretty easily when impacted and the boat indents. As was stated, replacing the gel coat is more or less optional. Getting the cloth saturated with epoxy is more important. Painting over the epoxy is a fine alternative.

I paddle composite canoes on whitewater, so I know a fair bit about the results of boats hitting rocks and scraping over them.

The white auto paint …
was recommended by the late Phil from QCC.

If you dont scrape it off dragging it on sand it will last as long as Gel coat.


The last time I did this I figured that a final thinner layer of gel coat polished really well (that last layer was where I lost interest myself since the boat was fixed up to work fine) would have been my last step. Auto spray is less work.

Sometimes, when we don’t care …
about aesthetics, we don’t use either gel coat or spray paint and just let the epoxy show.


In that event
I would at least cover the epoxy with some varnish containing a UV blocker to protect in from degradation.

Wouldn’t have worked for me
This was a drop on concrete, an edge at that, at a dock. The gel coat had come off right to the reinforcement along the inside keel, where the gel coat tends to be the thickest because it was where the hill starts curving up and narrowing. Very noticeable divot…

Now what is noticeable is an area of less than stunningly polished gel coat.

Fiberglass and gelcoat repair
It sounds like you need instructions for both. I have pics and instructions at:

Thanks, and a question
Thank you Mr. Nystrom, your albums were very helpful to me. If I may ask, in your opinion, is a respirator advisable/necessary for this type and scale of work, and if so, would you have a recommended type/brand? Dave

Lot’s of Info
Thanks again for all the info, I should be able to fix my boat now. Right now I am probably going to brush some epoxy on the fiberglass and then follow Brian’s photo guide on how to repair the gel coat. Nice work Brian.

That’s how I would do it.
I didn’t want to put my head on the block when gel coat was mentioned. Trying to match get coat is almost impossible and trying to get a smooth finish is tough too and almost not worth it. But an epoxy fill, sanded smooth with 300 wet paper and touched up with auto paint will look perfect.

Another way on the final paint is if you know an artist who can mix you a tiny bit of matching white to match (oil paint) with an alkyd dryer.