RE: [Paddlewise] gel coat/ how long is it good?

Joe Federici <fedo_at_hudsonet.com> wrote:
>>>Tuesday kayaking in RI near Beaver tail I chipped some gel coat on my
boat (romany 16). I've got  gel coat that was sent to me a few months
ago from NDK but I wondering if it still good. The container they used
was plastic and the seal was tight but by the way it smells in the area
I stored it I'm guessing not air tight. How can I tell if it's still
good? I'm planing on mixing some up before hand but wondered if anyone
had more insight. <<<

Some of the styrene may have evaporated but if you can still stir in some
catalyst the gelcoat should still harden. If it has dried out so much as to
be lumpy when you stir it, it probably won't do a very good job. Often times
for repairs it is handy to have it be a little thicker than normal, so a
little dried out can be a good thing. The styrene in the gelcoat will soften
some plastics (like the container it was shipped in). This might have
contaminated the gelcoat a little bit. You can always do a test and catalyze
a little of the gelcoat and see if it hardens. You could even put it in the
chip, if it doesn't harden right its easy to clean it out and try again.
Gelcoat usually takes about 2 to 3% catalyst for best cure. Over 4% inhibits
the cure so don't use too much. If you add a little liquid wax to the
gelcoat (known as "surface agent") it floats to the surface and prevents air
from inhibiting the cure on the surface layer. Using surface agent (or waxed
paper) makes the patch much easier to file and sand without clogging your
tools with gummy resin on the surface of the patch that has been "air
inhibited".
Good luck.

Matt Broze
http://www.marinerkayaks.com


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