Carbon/Kevlar kayak turning foggy/white. Help

Hello all,

I acquired this nice kayak (used) with a carbon/kevlar hull and it was in great shape but after a couple uses the inside is turning foggy/ whitish. It seems the area turning foggy is where the water sat for a while after paddling it. I can’t remove it by trying to wipe it off. What is happening? Did I mess it up already?

Thanks in advance!

It’s unlikely that you did anything to cause this. The key to determining the cause is to see what happens after allowing the boat to dry for a few days. If the whitish color disappears, it indicates that the layup is absorbing water when it gets wet. The solution is to clean and dry the interior completely, then apply a coat of resin over the interior of the cockpit to seal it. Epoxy is the easiest and arguably best solution.

If the boat has been used in salt water, you should rinse it repeatedly with fresh water to get as much of the salt out as possible before coating with epoxy. Once it’s dry, wipe it down with acetone and let that dry overnight, then coat it.


Some resins used in boat construction had a tendency to “blush” after water exposure. Bell Canoes were notorious for this, especially those constructed with an interior layer of “tweed” aramid. Are you sure that material is Kevlar/carbon hybrid cloth? It may be, but there is also a tweed aramid cloth consisting of contrasting fibers of natural and dyed aramid.

Either way try wiping the area down with an acetone moistened cloth. I think there is a good chance the blush will go away. But it will likely come back with repeated water exposure.

If an acetone rag wipe makes it go away and you want to prevent this from happening again you could apply a coat of a low viscosity “penetrating” epoxy.



Then wiping Flood Penetrol on and off will help repel water droplets that are causing the blush.

Yep acetone did the trick. Thanks, I may apply a layer of epoxy later on.
I’m pretty sure its carbon/kevlar (aramid).
Is this cloudiness by any change damaging the boat? Can constant application of acetone damage the finish?

No I don’t think it is damaging the boat. Brief applications of acetone should only affect the resin at the surface a few molecules deep and will not likely result in any significant damage but that gets old after a while.

Application of 303 Protectant or Penetrol, as suggested by Glenn, will retard the uptake of water molecules by the resin. But unfortunately, both will wash away over time. If you want to eliminate the problem you will need to apply a thin coat of non-blushing, low viscosity epoxy to the areas of the hull bottom that will see water contact for any length of time.

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Correct me if I’m wrong. With a product like Penetrol there will be a deposit on the surface that bonds. Almost like a varnish or paint that can alter the colors under it a little. I know it has become popular to use on old cars as a rust stopper over old paint and also used on old plastic to bring back sun damaged dull parts.

If the OP is thinking of at some point doing an epoxy over the surface would all this Penetrol need to be removed and would acetone be what you would use?

303 is not a that type of coating and more of a water displacer and would have to be done more often.

I have been using Fluid-Film on the outside of my poly hull on my canoe and it is a wool wax and known for water displacement. It has held up pretty good to sun and water this season. I have no idea how it would work here. :canoe:

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Flood Penetrol doesn’t permanently bond on a composite canoe. It wears off. It is especially good at making scratches and UV oxidation “disappear” for a few months. It does this by filling in the scratches and oxidized micro-pits, so when light reflects off the hull the surface appears smooth with a refreshed color. It’s just wipe on, wait 10 minutes and wipe off. Dave Curtis taught me this procedure, which he uses on all the used canoes he sells.

But it is only temporary and wears away. Two applications per season keep my composite boats appearing shiny.

On the inside of the canoe, Flood Penetrol also shines up the weave and, as long as it lasts, also acts as a sort of of temporary water repellent barrier to prevent the whitish resin blush. Sometimes I also put 303 Protectant on the outside of the hull after the Penetrol. None of this adds noticeable weight. A coating of epoxy might.


I think the water intruded from the water lying inside the hull? The affected area is not the waterline of the hull in the water.

303 and Woolwax won’t do much of anything for long.

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Thanks everyone for the replies. Really good information. The acetone did remove most of the cloudiness for now. I will give Flood Penetrol a shot. If it continues to show up and if it bothers me (which with time it may not anymore) I may apply a thin layer of epoxy. Thanks again!