Fiberglass Spider Cracks - NY/NJ/CT

I have a 10 year old fiberglass (Impex) kayak that has several spider cracks that I would like to repair. I do not have the facility to keep this boat indoors over the winter to complete this project.

Can anyone recommend someone that could complete these repairs for me in NY/NJ/CT area?

Kayak repair
The people at the Jersey Paddler in Brick, NJ, might be able to help you.

Good luck,


Spider cracks
CT Outdoors, Waterbury CT did some excellent repairs to my QCC that had some spider cracks. Talk to Dave.

You may want to consider…

– Last Updated: Dec-25-12 7:48 PM EST –

...not repairing them. Spider cracks occur in areas where the boat flexes. Repairing them doesn't change that and they are likely to reappear in the same places again. You could end up spending a lot of money for nothing. While spider cracks can be unsightly, they are purely cosmetic and repairing them is not mandatory for the longevity of your boat.

Spider cracks
When I asked Steve at QCC about the spider cracks he told me not to worry about them unless they are letting in water. When I suspected the boat was leaking I did a dye test indicating there were some problems with the gel coat in the bow area that had been previously repaired.

Gelcoat should not be the water barrier
A quality repair should be watertight before the gelcoat is applied.

"A quality repair should be watertight before the gelcoat is applied."

So the resin should be creating the waterproof barrier in a composite boat?

my impex spider crack experience
My force 5 is about 8 years old and has some spider cracks in the hull. It’s absolutely nothing to worry about. It developed these probably 4 years ago and I’ve had no issues with water entry or gelcoat chipping, bubbling or peeling away.

I have seen some spider cracks in other boats lead to gelcoat deterioration (bubbled and chipped off where the cracks let water behind the gelcoat) and therefore compromising the integrity of the hull, but not in my case.

Gelcoat is a cosmetic top coat. It’s only real purposes are to protect the laminate underneath and to look pretty. If the laminate itself is not waterproof, the boat is not built correctly. There should be sufficient resin in the layup to fully fill the gaps in the fabrics used in the layup and completely encapsulate the fibers. Resin-starved layups are not only leaky, they’re weak.

If the laminate is soft, damage evident on the inside or letting water in otherwise cracks are a cosmetic repair that can end up costing $100’s.

These are cosmetic only, but I want to repair before they become worse.

Sealing cracks?
I know gellcoat creack are just cosmetic,but my concern is water must get in and then be trapped and not dry easily causing future problems. They open during stress on the water letting water in,and close up when racked for storage.When they are repaired with resin or super glue,they just crack again soon. Is there something flexable one can seal them up with?


Most of the cracks in gellcoat I have seen go all the way down to the first outer fabric layer-you can see that if you push the hull out from the inside to open them up,so water must be getting there. No,the boat doesn’t leak as the fabric layers are fine. I was looking for a clear,low viscosity,flexable sealer? All my boats have vynelester gelcoat.


They typically don’t get worse
As I explained, they occur in areas that flex. Once they form, they pretty much stay in those areas and don’t spread. They don’t generally widen, either. Unless you happen to damage the glass an area that has spider cracks and need to do a repair anyway, they really aren’t worth fixing. If you’re really determined to do it, either learn to repair it yourself or you can plan on spending hundreds of dollars per year on repeated gelcoat repairs that just crack again anyway.

Hydrolysis can cause weakening and
blisters with some polyester resins. You can read about hydrolysis on the West Epoxy website.

But most composite kayaks and canoes now use vinylester resin, or in a few cases, epoxy. These resins are not susceptible to hydrolysis.

I had two gelcoated fiberglass canoes made with polyester resin, and both got gelcoat cracks. One blistered all over the hull, though I couldn’t detect a decrease in strength. The other didn’t even blister.

If you’re concerned about failure to dry, buy composite boats that don’t use gelcoat. I have a Dagger, a Bluewater, and two Milbrooks, all using only a very thin layer of colored resin. The next layer in is S-glass, very hard. The laminate dries quickly once out of the water, because there is no gelcoat overlayer to prevent drying where water has gotten in through the cracks.

If the laminate has been hammered until the resin and fibers are essentially beaten loose from one another, then some boat cloths with an affinity for water will soak it up a bit, but that water will NOT wick through the rest of the laminate. Kevlar loves water, but none of us paddling and slowly destroying Kevlar boats have noticed weight gain. Just give your boat plenty of drying time, and fix any crushed laminate when you get a chance.

I wonder what people think happens to inside Kevlar layers that are covered by wet, moldy floatation bags between weekends. I don’t think about it at all, because even though some Kevlar fibers are right at the inside surface of the laminate, they don’t get soggy with water. Weight measures confirm that.

What Bnystrom said
Paying to have cosmetic gel coat cracks removed is like getting t-shirts dry cleaned and ironed.

A friend had a carbon Chatham with 2"x3" cosmetic spider cracks in the black gel coated hull, the quote at $90/hr boat repair was $300. He did it himself.