Saturday, December 29, 2007

Bracewood - Part 1

A while back I began working with the three billets of bracewood that came with my kit. One was fairly straight grained and square with the grain, one was fairly straight but off axis, and the third was NOT straight at all. The first two I split to find the grain and then ripped along the grain. Then I split perpendicular to the grain along the medular grain. Unfortunately, this didn't yield anything very long because the medular was at a significant angle with respect to the length of the board.
See the third one at the bottom and the best I could do with the first two above that. So I called LMI and they sent me two more billets... they look straight at this point. I've been letting them acclimate to my basement over the past few days. Hopefully I can begin working with them soon.

Rationale: Braces are glued to the top with the grain top-to-bottom. It is important for the grain to be straight due to expansion/contraction of the wood during humidity changes. But it is actually more important that the medular grain is straight because this is the plane that is glued to the top. If any end grain is exposed at the gluing surface it significantly weakens the brace at that point. If end grain is exposed on the side of the brace along the normal grain it doesn't weaken the brace nearly as much as along the bottom of the brace in the direction of the medular grain. This is why bracewood must be split along the medular grain, while it is often acceptable to simply rip the billet along the grain direction if it is not too wavy.

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