David,
The swan neck with two peg boxes suffers from a design flaw that was corrected in the tripple peg box models. In a tripple box, a large main spar of wood runs in almost a straight line up the left side of the first box right through the second box. That provides the strength in the joint to the second box. The double peg box often is cut from a single piece of wood, and the left side of the lower box does not continue into the second box. It is cut with the end grain exposed so the fibers of the wood do not keep their strenght past that point. The offset between the upper and lower box creates a torque to the left (twist in the axis of the neck) on the upper box in addition to the forward (to the bridge) pull of the strings. It is that torque that pulls the top box off, more than the pull of the strings. It "peals" the repair open. There a many examples of these boxes on the internet, some of the best are on the Barber and Harris web site. If you look at the double box swan neck models there, you will see that they have widened the joint area to the top box to get the spar on the right side of the upper box to be one piece to the left side of the lower box. Some unwanted weight is added with the extra large joint area but there will be no twist problem warping or breaking the top box joint. There are other lutes on the web with small joint areas already twisting and bending to the left, leaving a gap between the 8th and 9th courses. Solutions: 1) If the repairman is sharp, explain the nature of the forces involved and slice a larger piece of wood between the two boxes that adds more strength and mass to the right side of the joint as well as the left side where the break is obvious. 2) Graft a larger piece of wood between the two boxes. If you have seen how a violin or cello neck is grafted to a peg box, you will see what kind of joint is required. This requires a skilled repairman, and some esthetic redesign. 3) Go to the local woodcarvers and have them make a new complete box with the improved wood mass between the two boxes. The old peg box can be sawed off close to the joint and then the remnants carved off to the original neck wood. A luthier could then match the new box to the old lute and refit the pegs. If you do this you should consider converting to a tripple peg box. 4) And now for the best one: glue the box back on and use much lighter strings (yuck). Louis Aull -- To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
