Re: [Paddlewise] Graphite for Bottoms

John Winters wrote:
>As for carbon filled resin being more abrasion resistant I have seen no
>test reports to support that. My experience suggests that the resin
>hardness contributes more to abrasion resistance unless one uses a really
>hard filler like metal powder etc.

I'd agree with John on that.  From what I've heard from others (I've not
tried it meself), abrasion resistance seems to increase with the addition
of the graphite powder.  Personally, I think it's just the slipperyness of
the graphite, rather than any increase of hardness of the resin (that last
is probably nil).  

John's the last word on slipperyness in the water as far as I'm concerned,
so heed his info on that.  

Long ago and far away (20+ years ago in Chicago) some slalom racing kayak
building friends of mine dumped some metalflake glitter into the resin used
for the first layer of one boat and later noticed a remarkable increase in
the abrasion resistance of that one over the others they had built at the
same time.  Probably is something to the carborundum or aluminium oxide
(both are used in sharpening stones for knives, etc.), but is it worth the
added weight in the boat?  High concentrations of any filler degrade resin
strength properties, but I don't know what the "high concentration" limit
for stuff like that is.  Probably higher than most people would use,
anyway, so may not matter.  

Good luck with it and let us know how the experiments turn out for you.   

Hank Hays
Lightning Paddles

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