Date: Fri, 30 May 1997 10:24:19 -0400 (EDT)
From: kolsen@imagelan.com
To: baidarka <baidarka@lists.intelenet.net>
Subject: Re: Jawbone kayak? (fwd)
I've been a bit slow forwarding these of late, minor problems syncing my
latest email address with the mailing list software.
---------- Forwarded message ----------
Date: Thu, 29 May 1997 17:42:56 -0700
From: Jim McKay <jmckay@ctf.com>
To: baidarka@lists.intelenet.net
Subject: Re: Jawbone kayak?
BWHITTEM@mailgw.sanders.lockheed.com wrote:
>
>
> has anyone on the list built a kayak from the zu freeman
> book "jawbone kayak? i am starting and would like othere
> views on it.
> thanks
> barry whittemore
> manchester,nh
I have made a "jawbone kayak." I made it 15 ft. long and 30" wide, and
covered it with 14 oz. nylon coated with polyurethane and hypalon. Here
are my views:
Some of the instructions get quite confusing, and some of the part
templates just did not work, so you have to check everything yourself
and trim the size of the parts to fit those already assembled. I
definitely would not make the frame the way the book instructs. Instead
of making the latitudinal ribs from strips of plywood I would cut them
out from one piece of plywood, saving an awful lot of time, glue, and
screws. Generally the frame went together OK, except the ends of the
hull get a little tricky and if I remember correctly I had to remake the
vertical pieces at each end because the book gave incorrect dimensions.
The skin went on reasonably well, but the rectangular cockpit caused
problems, I was not able to avoid wrinkles in the skin at the corners of
the cockpit. The boat weighs about 50 lbs which is over 10 lbs. more
than I had planned, but that may be more due to the coatings on the skin
than the frame, which seemed easy to move around during construction.
My main disappointments have been with the operation on the water. The
width of 30" is too wide for a boat as deep as the Jawbone and with a
flat top deck, with the result that your knuckles hit the deck quite a
bit and you have to hold the paddle higher than you should, which can be
tiring. The boat has so much volume that with only one person in it the
hull is not fully immersed (i.e. the ends are out of the water) with the
result that it does not track (even with 2 persons it is bad) and I have
had to add a skeg. Some of this may be due to the extension from the
original design of 12' to 15', I would not recommend building the
"jawbone" as a double for this reason. I would also recommend reducing
the depth of the boat and considering some pitch for the top deck so
puddles of water do not sit up there. The look of the boat is well...
not that appealing. No where near as sexy as the other skin-on-frame
designs discussed in this mailing list.
The good news is that the kayak does float and moves through the water
reasonably well, although you will not win any races with it. It is
very stable, you can lean right over the gunwales without tipping, and
you can stand up in it briefly. If you are comparing it against a
rowboat or rubber raft it is not bad, but against a real kayak it loses
out. My wife and small son and I have all crammed into it and had some
real fun on the water, but I would not make another one. I am trying to
decide whether the next project will be a baidarka or a stitch and glue.
If you have any specific questions I would be happy to respond.
---------------------------------------------------------------
Jim McKay, P.Eng. -- Leader, Electronics Production Group
CTF Systems Inc. Ph: (604) 941-8561
15-1750 McLean Ave. Fax: (604) 941-8565
Port Coquitlam, B.C. email: jmckay@ctf.com
Canada V3C 1M9 Web Page: http://www.ctf.com
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