Hydrolysis can cause weakening and
Posted by: g2d on Jan-03-13 7:34 AM (EST)
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.
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