Wednesday, September 5, 2012
The Triple Nut Extension - Continued
I laid out the boundaries of the smallest cavity (you can see several reference lines) and proceeded to partially excavate a small area with various sizes of chisels. Working like this it becomes obvious how to proceed: truing the edges, then deepening the recess, lengthening it a little and then truing again. I found that the work went quickly and neatly.
The first pegbox is a little more complicated in that the treble side has several crooks and curves. I lay these out with generous side cheeks which provide strength and stability. Here I am using a front bent chisel to clear the bottom of the recess. I like to leave more than six millimeters of wood thickness in the bottom of this pegbox for strength. I can achieve this even with the relatively low profile of the pegbox by drilling the holes off center and closer to the top edge by a millimeter and a half. Although I found this work pleasing I still felt I needed some aesthetic gratification. I reamed out several peg holes in the finished pegboxes and inserted temporary pegs to see what the final product would look like.
This photo also demonstrates how I clamp any of the types of extensions that I make. I tie two wound bass string of the same size in the appropriate holes in the bridge at one end and on pegs in the pegbox. When these strings are brought up to equal tension the extension is pulled back into the neck joint in proper alignment. Two spring clamps hold it firmly against the bottom of the neck.
Next time I'll show photos of the finished lute and describe a surprising historical varnishing process.
Posted by Michael