Friday, April 18, 2008

Carving Gunwales...near disaster!

Next up in the build, I attempted the challenging job of carving the gunwales. Adney's sketch for the 11'8" Attikamek Hunter's canoe had a thinner gunwale assembly than most others - the cross-sectional dimensions for the inwale were ⅝" wide by 1" thick (most others were 1" x 1⅛"). This smaller inwale at quarter scale meant 5/32" x 1/4" and at nearly 3 ft long it would mean a thin delicate piece of wood that would need skillful carving.

Given my confidence in building the kit so far, I was up to the challenge. The kit came with a suitable-length piece of cedar which required multiple splitting and shaping to the inwale's delicate dimensions. First the cedar piece was soaked in warm water in the bathtub overnight to soften the wood further (apparently making it easier to split). When the actual splitting began, I used my trusty Mora Canoe Knife with its razor sharp edge to begin the split.

Splitting the soaked cedar

The provided piece of wood split easily enough but I noticed that the grain was quite curvy in the middle resulting in an uneven curve when split along the natural lines. In a full scale model, more care would be taken to ensure the gunnels are carved from the straightest length of cedar possible. Anyway with more splitting, an acceptable plank batten was obtained.

The batten for the inwales; cracking the precious cedar

Readings suggested that the inwales and outwales be carved from the same batten so that they would naturally balance in terms of tension and this is what I tried to do. Unfortunately the curvy grain meant the the split seriously wandered to one side and I simply couldn't contain the split to bring it back to center no mater what I tried. The battens kept cracking and breaking with my attempts or they would wander and split with one piece two short for the inwale length. No problem...lots of wood I thought, until it happened again and then again. With less & less wood and more & more panic, I finally was able to split 2 pieces of appropriate length but their curvy grain resisted accurate carving. They ended up quite warped and unsuitable for inwales in my frustrating!

At this point, an executive decision was made to save this project for near failure by using the provided sheer sticks (long, 36" pieces of thinly carved cedar meant to measure the angle of the canoe lines) for the inwales. Quite fortuitous that they happened to be exactly the dimensions of my model's necessary inwale dimensions while also having the angled notch for the ribs pre-cut onto them as well. These were probably low-quality reject gunwale pieces from another kit, but for my purposes they were what I desperately needed. The pics below show the provided sheer sticks with my sorry carved inwales for comparison.

Split inwales from a single batten; comparison of sheer sticks with my butchered gunwales

With this lucky gift, I could proceed to form the inwale assembly. While the precious inwales were soaking in the tub, I turned my attention to making the temporary thwarts that would stretch the assembly apart to the necessary dimensions. These pieces came from the broken gunwale attempts and were carefully measured from the Adney plans. A center thwart measuring 6¾", two intermediate thwarts measuring 5½", and two end thwarts measuring 2". The edges of the middle and end thwarts were angled to fit the curving inwales and holes were punched in the wood with an awl (provided as part of part of Ray Jardine's Knife Sheath Kit).

Temporary thwarts

After tying the ends with wet spruce root, the soaked inwales were placed side by side and the thwarts locations marked. At this stage, the lashing points were marked as well. In a full scale canoe, lashings are placed at 2" intervals, meaning ½" for the model. The lashings marks started at the centre thwart (¼ " on either side of the center line) and then continued at ½" intervals until the end thwarts. These marks were marked with a pencil and will be covered when the whole gunwale structure is lashed with roots.

Marking out lashing points

The temporary thwarts were carefully placed in the streched frame and tied into place with some waxed thread left over from the Knife Kit project. Tied with slipknots, these temporary thwarts will be replaced by the real ones when the gunwale assembly has been pegged and lashed.

Tying the temporary thwarts; final inwale assembly

So far so good, with the inwale assembly ready, I made the height posts (shearing posts) which are place on the bottom of the frame and support the inwale assemble at the proper height. Calculations from the Adney plans as well as John Lindman's Tips page meant I needed 2-1/16" high posts at the centre thwart, 2-3/8" posts at the intermediate and 4-3/4" posts at the end thwarts to get the desired sheer. These posts were cut from leftover 1-1/8" square poplar pieces from a discarded piece of paddle shaft. In the end, I cut two many end thwart pieces without thinking that these couldn't fit in the tapering ends of the canoe anyway.

Cutting the height supports from scrap 1 1/8" poplar

Finally the moment of truth, setting the inwales into the canoe. This involved removing all the cross-ties and inner staves while delicately positioning the assembly perfectly centered on the height posts and clamping. My horrible inwales could still be used however, shaved down more delicately to the less important outwale structure. These were then placed on the outside the boat effectively forming a sandwiching layer holding the bark in place. After clamping with the provided clothes-pins the whole structure must now dry for 2 days before pegging and lashing can commence.

Setting the inwale assembly; Laying the outwales, Sandwiched bark between the gunwales

All in all, a frustatingly tense but rewarding day. Next up, carving the ribs, stem pieces, and permanent thwarts while the gunwales dryout and set.

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