Monday, August 31, 2009

Tuktut Nogait Bow - Second Glance

I've been moving ahead cautiously with the Tuktut Nogait bow reproduction. My plan is still to make two bows side by side, one will be the antiqued reproduction for Parks and one will be a shooting bow for myself. So far, I've stripped the bark from the staves and made a more detailed pattern and examination of the bow itself. Please, if you are an archer or a bowyer and you see me making a mistake along the way, let me know - this is new territory for me.

Yew grows with a dense red heartwood interior and a softer yellow sapwood just below the bark. English longbows are made to take advantage of the different properties of these two wood layers, with the yellow sapwood left on the back of the bow and the red heartwood left on the belly.
The sapwood responds well to the tension on the outside of the bow and the heartwood takes the compression forces on the inside well. However many bows, especially in North America are made on the heartwood alone, with all of the sapwood removed. The Tuktut Nogait bow is very weathered, but I wanted to double check for sapwood before I made any irreversible cuts to my staves. I couldn't see any signs that the bow had any changes throughout its thickness, so I'm confident that its made on heartwood alone. I feel like I can safely remove the sapwood now.

The inside of the fishtail splice on the short limb gives the best view of the grain of the wood and its very flat, with the back following a single growth ring. The main part of the bow is pretty desicated and its tough to see the grain, but I don't believe its made quite the same way. It looks like it was made on a smaller diameter tree and the back of the bow cuts across several growth rings. This is called decrowning. It's not quite as desirable as following a single growth ring for the back of a bow, but if its done properly and the growth rings run the length of the bow, it will work. Although it makes me wonder; if the spliced limb is a repair from an originally complete bow that broke, then perhaps the weakness that comes from cutting across growth rings was a factor in the broken limb.

For the reproductions, understanding how the bows were made relative to the wood grain helps make a few decisions. I think the staves that I have will allow me to make one flat bow which follows a single growth ring for the back and a second one with the same dimensions, that will be decrowned to match the body of the bow. When both are done, or almost done, I'll cut off one limb from each and swap them. The decrowned bow should also help with the antiquing work, because it will be easier to get the weathering and cracking that I need if the wood grain is visible on all sides of the bow.

Finally, I think the fractured end of the bow is less random than it first appeared. I think that part of the string nock is intact, which helps a lot. It shows the style of nock, which is consistent with other cable backed bows from the arctic, it removes the worry that there may have been a missing and unknown composite material used to tip the bow and it means that I have all of the length, width, and thickness measurements available from the centre of the grip to the tip of the limb. It removes a lot of guess work and means I'll have more confidence in the accuracy of the reproduction.

Photo Credits: Tim Rast

Photo Captions:
Top, Using the draw knife to strip the bark.
Second, The Tuktut Nogait bow
Third, The end of a yew stave showing the yellow sapwood and the red heartwood
Fourth, Inside the spliced limb - you can see the wood grain. The limb is held belly side up.
Fifth, diagram of the placement of the spliced limb inside a stave
Sixth, diagram of the placement of the bow inside a smaller tree
Seventh, The end of the Tuktut Nogait bow showing the reconstructed stirng nock

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