Soundboard and Back
Making the soundboard and the back is going to put you through some heavy ripsawing. You can do it—it just takes a little time. 1 used an old, green-hearted tulip poplar board from a hog pen and sawed it into two Vfc-inch-thick sheets, 7 inches wide, ready for planing. The sawing takes about thirty minutes for each cut, which gives you ample time to contemplate your recent misdeeds. You could make the job easier by cutting in around the edges with a circular saw and just finishing up the middle with the handsaw. You could also rip wood 3V$ inches thick and glue the two halves together along the center edge into a "book match." This is how fineinstruments are made to ensure symmetrical density.
Another tactic is to find wood that is already cut pretty thin. I have often heard of instruments made from dynamite cases. The dynamite doesn't impart any special tone, but the nitroglycerine absorbed by the wood can give you a terrific headache. The point with the dynamite cases is that the wood is already thin enough that it can be brought the rest of the way down with a plane. These days you can often find wooden crating sawn from tropical trees, some of which must be giant poison ivy trees, because the sawdust has the same irritating effect on your skin. In any case, stop planing the stuff when it gets below V& inch thick—Vie inch is too thin. By now you know what a pain it is to get thin, flat wood and how bad you would feel if you were to accidentally crack the back or soundboard while sawing it to shape. You will find that it's safer to cut the outline by keeping the wood flat against a flat board as you slice in with a sharp, thin-bladed knife in several deepening passes. Be sure to cut the outline oversized by Y& inch all around. You can either trim it up flush or leave a slight overhang after you have glued it to the sides.
Just as the archetypal dulcimer has double-curved sides (like the traditional male two-handed sign for a woman's figure), it typically has four heart-shaped soundholes in the face. Variations in the soundhole design and placement are the distinctive signatures of individual makers. You can make the conventional heart quickly by boring three holes in a triangle and then finishing the shape with a knife. You can also ruin a lot of work by accidentally splitting the soundboard with the screwpoint of the auger. Either predrill clearance for the screwpoint or use a center bit that has a center pike rather than a leadscrew. If you are going to hollow out the underside of the fretboard (which comes next), you should also cut the long openings into the top beneath where the fretboard will be glued by this same method of boring first and slicing out.
"The Woodwright's Eclectic Workshop" By Roy Underhill
© 2012 The University of North Carolina Press