Design One: This is the "wavy cut" design. In this design, the loom was cut lengthwise so that it could be put back together using a few wood screws (I was hoping to pin the pieces somehow if the design worked. Harry suggested using bone, or something like that). I thought the lengthwise cut down the center of the loom would reduce horizontal sliding movements between the two pieces during paddling. It worked quite well - for awhile. Then one evening I laid the paddle between two saw horses and decided to test it's flexibility. I learned something. It was flexible. Very flexible, right up to it's breaking point. Then it snapped like a twig. Unfortunately, it broke too easily and was obviously not a paddle I would want to take on an outing. The break occurred in one of the numerous thin sections created by the wavy cut. I hadn't noticed this thinning before, but they were all-to obvious after the break. Scratch one perfectly good western red cedar paddle. Back to the drawing board, as they say.
Problem: What other kinds of joints are capable of handling the stresses at the mid-point of Greenland paddle, yet allow for a paddle to be broken apart and reassembled easily?
Short answer: Not many.
A mortise and tenon joint is usually used to attach two pieces of wood in a 90-degree joint. There are few joints suitable for attaching two pieces of wood that butt up against one another. I decided to use an extended-length mortise and tenon (There is probably some technical name for this joint, but I don't know it. If you do, please let me know.). The tenon runs several inches into the loom of the adjacent paddle halve and is meant to offset shearing forces at the joint itself. Both it, and the loom, per se, are made of maple to resist edge compression that will occur at the faces of the joined pieces. The tenon itself is "loose." It is cut as an independent piece. It's glued into one of the paddle halves to become a permanent part of the paddle. Once fixed, the tenon becomes the anchor used to pin the mortised paddle halve to it's mate.
I foresaw cutting a deep mortise joint as the main problem. How does one cut a 4 inch deep square hole perfectly centered in two axes of the adjoining paddle loom? The answer is obvious. One doesn't. You build the loom around the mortise. Realizing this, a second problem arises. If you build the loom out of dense maple, how to you prevent the paddle becoming too heavy for normal use? Answer: You laminate it to light cedar blades. In short, you build the paddle blades around the loom.
The loom is lengthened by attaching lighter western red cedar to it using a pinned mortise and tenon joint. The attachment is strengthened by overlapping wood layers on both sides. At this point, the paddle is a laminated blank that can be broken into two pieces. It must be planed, filed, and sanded into shape. The finished product is shown below.