Date: Fri, 20 Mar 1998 10:01:00 -0600
From: Wolfgang Brinck <wolfgang.brinck@hksystems.com>
To: baidarka@lists.intelenet.net
Subject: Re: [baidarka] Frame questions
Dana A. Dickson wrote:
>
> I am building a greenland kayak following Bob Boucher's video as a guide.
> I purchased 100 in clear northern white cedar for the frame. I intend to
> scarf the pieces for the gunnels, chines and keelson. Does anyone have
> advice on where the scarfs will least affect the fairness of the curves. I
> am planning on a 12:1 joint. I am contemplating putting the 8 ft section
> in the middle and scarfing on 4 ft. 8 inch pieces at either end, hoping
> that that configuration will give me even and smooth curves.
>
> I am going to use split, not sawn white oak or black ash for the ribs. Any
> thoughts on these choices?
>
> Although the video does not discuss using split wood for the long frame
> pieces, I would expect they would be somewhat different in performance than
> the sawn frame members. Has anyone out there tried framing this way?
>
> Thanks for the help.
>
> Dana Dickson
I had access to a Greenland Kayak from the collection of Ralph Frese who
owns the Chicagoland Canoe Base. This boat has scarfed gunwales. The
scarf
is about two thirds of the way back from the bow - in other words,
behind
the cockpit. The scarf is a hook scarf which is also pegged with quarter
inch
ivory pegs. Ribs are split branches of roughly one to one and a quarter
inch
diameter. One of the reasons for the scarf is the dramatic upsweep of
the gunwales
at the tail. This upsweep, kind of like a duck tail is carved, not bent
and
requires a wider board than the 4 inch board used fro the front part of
the
gunwales. So scarfing is a way to save on lumber. The chine stringers
on
this boat were also scarfed. I don't think that this was the usual thing
to
do, but I think the boat used to be shorter, maybe a child's boat and
was
then stretched to full size by extending all the longitudinals by
scarfing
on longer tail pieces. Incidentally, since none of these scarfs were
glued,
the builder placed them in a place where the lines of the boat were
reasonably straight.
I have had squirrels chew up one of my boats - they like to collect
string
around nesting time and found a lot of it in my boat, holding frame
members
together. Rather than replacing whole stringers, I scarfed some of them
- quite
successfully too I think. I carved a hook scarf which in itself seemed
quite
stable, but since I could, I also epoxied it.
Svend Ulstrup who was Bob Boucher's teacher built a 20 foot double by
scarfing
the gunwales. He used a simle tapered scarf and glued it (Elmer's no
less)
I don't remember if he also pegged the scarf. He may have. Epoxy is
better than
Elmer's of course, but the Elmer's seems to be ok as long as the joint
is sealed
and waterproofed.
In any case, I did a 16 mile crossing in the boat and the Elmer's held.
I am not recommending water soluble carpenter's glue of course, I am
just
trying to point out that given enough care and ingenuity, you can get
by on low tech.
As for performance of split vs. sawn lumber, I don't think you could
tell the
difference in a Greenland boat. Split is slightly stronger than sawn for
the
same weight, so you could get a slightly lighter boat, but other than
that
you wouldn't notice. Greenland hulls are built stiffer than baidarkas
and
somewhat heavier overall, so no difference.
More significantly though, white cedar is not as strong as the yellow
pine
that Bob Boucher uses or the traditional spruce that the Greenlanders
used,
so you might want to go with little more width on your Gunwales than Bob
recommends. I have a Greenland boat that I used red cedar on and the
keelson cracked on me. The gunwales which I did the traditional 3-1/2
inches
deep did not crack.
By the way, I have made a detailed drawing of the Greenland boat,
including all
the scarfing. If you want to get a copy, contact me at
native.water@mixcom.com
--
* * * .oOo.oOo.
wolfgang. /| * * * /| *
brinck@h / oo wolf o | *
ksystem / \ wolf / |
s.com / | wolf / | howlin' wolf
\ / | \ / | courtesy of
\/__\m \m \/__\m \m Larry Andrus