[Paddlewise] Keel Abrasion, Composite Boats

Peter said:

<<< I re-read Doug L's seam improvement article just now
(http://www.nswseakayaker.asn.au/mag/43/seams.html). Doug mentions
"adding an exterior and interior keel of UMHW plastic and ash
respectively
(bolted through the hull),">>>

Peter, that's UHMW. I think there was a typo in the article. My latest
keel is a bit thicker and I used a softer material called "Starboard" as
the UHMW gets brittle with age and UV damage. The NSW article wasn't
specifically about "abrasion ablation" (as Dave Kruger calls anything
sacrificial like gel-coat, etc), but rather about kayak stiffness. I
mentioned the modification, because I wanted a bomb-proof hull with no
hint of oil-canning and complete longitudinal stiffness. The
modification also provided the sacrificial aspect, too -- of course. I'm
certainly not promoting the modification, just explaining my way of
doing things as part of an overall scheme to reinforce my kayak for
hard-core use. .

<<<I am interested in methods of preventing abrasion of the boat keel,
and
wonder:>>> <snip>

The "normal" way is to add layer(s) of epoxy and additives, either
aluminum, teflon, etc; or you can add strips of cloth tape, etc,
impregnated with epoxy or other mixtures. In my lectures and
demonstrations on this subject, I often promote Marinetex (tm) as it is
easy to use and wears very well. It is expensive, but the consistency of
the mixture is difficult to duplicate with home-mixing of the necessary
ingredients - IMHO.

For the wooden boat builder, they are already up on the whole epoxy
system and the advertised proprietary additives for keelson wear (the
products are actually generic, and can be cross-used with various epoxy
systems and even polyester resins.

The only reason I went to a tougher solution (my plastic/brass keel
strip) is that the other methods did not last. YES, I prepped properly,
did all the right things with the epoxy methods, but stuff just doesn't
stand up to my brand of punishment and BC's brand of barnacles. And if I
do ever head down to Australia's big, bad surf with my Nordkapp, and
break the kayak in half, the keel will hold the boat together :-)

Doug Lloyd (who hopes he isn't wearing too thin on this list)



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