Message-Id: <97Apr8.170919edt.14836-2@prufire1.prusec.com>
Date: Tue, 8 Apr 1997 19:15:33 -0400
From: carl_vonkleistiii <carl_vonkleistiii@prusec.com>
To: baidarka@lists.intelenet.net
Subject: Springtime activities
Hey, y'all!
I have been working on my boat frames as the weather has begun to warm up and
cooperate some. I have now 4 deck frames (gun'l's, noseplate, tailplate, and
deck beams) complete and am working on putting the deck beams on the 5th
frame. When I began, I cut and drilled the gun'l's and put the spacer boards
at the proper locations...then the boats sat outside in the weather over the
winter. Those that had either the nose and tail plates and/or some deck
beams installed came through the winter weather fine, but one, the 6th frame,
was simply the gun'l's and the spacing boards. It distorted beyond belief
and I am going to have to start all over again on those gun'l's.
I cut all my gun'l's from a couple of 2x12x16's. The lumber was NOT
vertically sawn, but the way it was cut the wood on each side of the edges of
the boards was close to vertically cut. When I examined the grain of the
twisted gun'l's it appeared that I had used wood from closer to the center of
the boards where the grain was not nearly vertical. The twisting appeared
pretty random, and that probably speaks to the importance of using more
vertically grained wood.
Installing the nose and end plates was very straightforward, but when I
started mortising in the deckbeams I ran into a problem with the gun'l's
developing an inward twist. This forced the split nose and tail plates to
twist downard out of alignment. They are about 1/4 to 3/8 of an inch lower
in the center than at the gun'l's. I didn't figure out what was going on
until the third frame. I was cutting the mortises so that they were parallel
with the tops of the gun'l's. When I installed the tennon on the deck beam,
the angle of the tennon was less than the angle of the mortise, and it caused
the gun'l's to twist inward to conform to the angle of the tennon on the deck
beam. I may just go back and build new nose and tail plates for the first
two boats to fit the altered geometry of the gun'l's.
On subsequent frames (3-5) I corrected this by cutting the mortises into the
gun'l's at an angle just a hair above being straight across the frame. This
worked well for the deck beams toward the center of the boat, but toward the
ends, where the gun'l's develop some twist (i.e. are angled more toward the
centerline where the hull has a sharper form) this caused a different
problem. I had been marking the location of the mortises on the outside of
the gun'ls, with the top of the mortise 5/8" and the bottom of the mortise
3/8" from the top of the gun'l'. On the deck beams close to the ends of the
boats, this causes the mortise to come out lower down on the gun'l's' inside
than the outside, and the fact that the mortise is lower on the inside of the
gun'l' means that the deck beam will also be in a lower position.
Some of the deck beams on my boats are almost a quarter of an inch lower than
the top of the gun'l'. They probably should be flush with the top of the
gun'l'. However, I think that this clears up a mystery! I think it was in
David Zimmerly's book, QAJAQ, that he at one point mentions that a particular
boat he is describing has the deck beams set slightly below the edge of the
gun'l's instead of being flush with them as on other boats. Maybe this
occurred because the builder followed the same measuring and construction
technique (mistake?) that I described above! It is kind of comforting to
suspect that the ancient makers were as prone to make mistakes as I am today
(well, maybe that's a bit twisted.) Anyway, on frame #6 I will be measuring
the location of the mortise from the inside of the gun'l'. This will locate
it higher on the outside, but it will get the deckbeams level with the
gun'l's.
One other thing that I have noticed about the frames is that none of them are
perfectly symetrical along their length. In fact, the frame that I was
building for myself was remarkably asymetrical until I sanded one gun'l'
thinner to allow it to bend more toward the center of the boat. It still
isn't perfect, but like I keep telling myself, "it's not going to be perfect
-- it's handmade!"
On one frame I discovered a knot that I had overlooked (intentionally?) in
the wood of one of the gun'l's when I cut it. The knot wasn't one of the big
round ones, but a long thin one. It was perhaps 1/4" wide, and on one side
was barely 3/4" long, little more than a dark streak in the wood. On the
other side of the gun'l', however, it was about 3/8" wide and 3" long. It
was full of soft, resinous wood that appeared to be bark that had been grown
over by the rest of the wood.
I was pretty irked, and decided that rather than try to replace the gun'l'
after having already finished the frame I would attempt a patch. I used a
chisel to scrape all of the bark out and get the wood down to the clean,
non-sticky wood surrounding the knot. Then I mixed up about an ounce of
polyester resin thickened with a handfull of sawdust to the consistency of
mayonaise -- just barely stiff enough to be shaped without running. I lay
the frame flat on my deck and slipped a one foot square piece of plastic
grocery bag beneath the knothole. I filled the knot with thickened resin,
wrapped the plastic around the section of the gun'l', and then tied two short
flat lengths of wood over the knot to hold the resin in place and keep the
surface flat as it hardened.
The next day, I removed the wood and plastic (which won't stick to the epoxy)
and examined the gun'l'. The patch was smooth, with only minor overflow, and
appeared to have made a strong, solid bond with the wood. I flexed the area
as much as I could and poked at it with a stick, but the patch didn't seem to
want to come out. Hopefully, it is a permanent and durable fix that won't
get popped out of place by heavy flexing/pounding in use.
I am getting reasonably neat, tight joints using just a circular saw to shape
the deckbeams and a skillsaw to cut the tenons on them. The 3/8" drill bit
and 3/8" chisel are THE tools for cutting the mortises. As always the
hand-held belt sander is a good all purpose tool to have handy. I have been
using nylon twine to pull pieces together and hold things in place where
needed.
The next step is to get out on one of the local rivers and get some willow
shoots. It will probably be a couple of weekends before I get to that point,
though.
--
Eric von Kleist We pray for one last landing
Hilton Head Island, SC On the globe that gave us birth,
USA To rest our eyes on the fleecy skies
And the cool green hills of Earth.
Carlyle said, "A lie cannot live"; it shows he did not now how to
tell them. Mark Twain
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