Monday, December 9, 2013
Thicknesses start at about 2.4 mm in the vicinity of the bridge, thinning to about 2.1 at the periphery.
One thing I've learned from looking at older instruments is to leave a little space between the end of the bars and side. The box of a guitar is apt to shrink a little bit over time. The top and back can contract, but the transverse bars don't shrink much at all, oriented longitudinally as they are. If they butt right up against the sides they inhibit the contraction and can cause cracking. I store my materials carefully and build in a controlled environment but one never knows what humidity conditions an instrument might find itself subjected to during its lifetime.