Kevlar kayak layup concern

My kevlar kayak has a clear gel coat hull. I’ve noticed the hull makes a wobble sound going thru waves, due to the hull flexing. I have now noticed small clear bubbles that have developed in the hull, looks like the clear gelcoat has seperated from the kevlar. Does this sound right? Is this due to too much flex in the hull? Should I be concerned? THANKS

What is the brand
of kayak? If you can see the kevlar from the outside there is no gel coat. That is just the epoxy on the kevlar and the small air bubbles are to be expected, though they should not increase over time.

A properly designed “Kevlar” kayak
should not be flexing except when clipping an obstacle. But are you sure it IS flexing? The noise you hear may not indicate anything.

Maybe you could put the boat in a pool or in a clear lake, with someone else in it. Then, wearing a mask or goggles, you can go under the boat and see how easy or hard it is to depress the hull. You may be surprised at the amount of force it takes. It is unlikely that water forces during paddling are going to push the hull inward with every stroke.

Gelcoat can be clear

– Last Updated: Jul-08-06 7:22 AM EST –

The fact that you can see through the finish does not indicate that it's not gelcoat. Most gelcoat is tinted (typically white) for improved UV protection and to hide scratches better, but it doesn't have to be.

Some added Kevlar Info.
I am not an expert on Kevlar, but this is what I learned when I was trying to decide on what “I” wanted to buy.

Kevlar is a very TOUGH fabric, but not “Stiff”. This is why Kevlar is not often used alone for a composite hull. Kevlar can flex if used alone in a composite hull.

This is why Kevlar is often combined with Fiberglass, or Carbon Fibers, as these two fibers are stiff, but not TOUGH, like Kevlar. Fiberglass fibers, and Carbon Fibers are not tough. Carbon fibers are very stiff, but can break easier than Fiberglass fibers. Both Carbon and Kevlar are lighter weight cloth than Fiberglass.

My Kayak hull (Impex Assateague) has a combination weave of carbon fibers, and Kevlar fibers, in one cloth. The carbon provides the stiffness, and the Kevlar provides toughness. If I hit a hard object, the hull may flex inward enough to break the carbon fibers, but the tough Kevlar fibers should keep the Hull from being penetrated, and let me get “home” safely.

I hope this has been of some help!

That is new to me for a kayak
the only time I have seen a kevlar kayak with a clear coat was by Seda, and they do not use a gel coat for that model. I have also never seen a manufacturer offer a “clear gel coat” on a kayak, have you? And with kevlar and its know sensitivity to UV, I can not see why anyone would use a clear gel coat.

This is true. I just ordered some
Kevlar/carbon weave for experimental patching. Although I would prefer a Kevlar/S-glass weave, which seems not to be available.

no you shouldn’t be concerned
a thin light hull material with some slightly flat sections and no core material can wobble or ring. I had a necky swallow in kevlar with carbon strips,it flexed up about 1" when launching at the beach. I’ve paddled a glass Chatham 17 that had a discernible “boing” when landing down on waves. I wouldn’t worry about it.

Still though, just because it is …
happening on these boats doesn’t make it right. Boats SHOULD NOT move ‘in and out’ on the water under everyday conditions. Boats wallowing in surf are a different story.

I honestly haven’t researched…
…if anyone is building (or has built) boats with clear gelcoat, but there’s no reason that it can’t be done, so you can’t discount it as a possibility. I use a fair amount of gelcoat when doing repairs and it’s naturally clear unless you buy it pre-tinted. As I said above, tinting it improves its UV resistance and better protects the underlying layup from sun damage, which it why it’s typically tinted in commercial boats.

I am not arguing that you can have clear gel coat. But the question is, does any manufactuer use clear gel coat on a kayak and in particular on a kevlar kayak?, since that would answer the posters question.

I have never seen clear gel coat offered on a kayak, and I have looked any every “searchable” maunfactuers web site, many dealerships, and several kayak festivals in the USA in the past 6 months.