SOUNDBOARD THICKNESSING AND DEFLECTION TEST - PART 2.

After much debate and recommendation from fellow builders, I decided to thin my soundboard even further. Same procedure as last year Miss Sofie.........

After careful planing, I ended up with a final thickness in the bridge area of 2.2mm and 1.8mm around the periphery. The 2.2mm thickness extends all the way from the bridge, up past the rosette, to the top of the soundboard, slowly graduating out towards the sided in a pattern parallel to the center seam. Below the bridge area the thinning follows the contour of the lower bout. In other words the thinning forms a kind of a U-shape, rather than the shape of the guitar itself.

I also repeated the deflection test and it came out showing 7.5mm of deflection; Significantly more than before but still a little stiffer than the 8-9mm target. However, at this point the soundboard felt very flexible indeed and flexing it cross grain with my hands, I was afraid of snapping it in two. It was also hard for me to detect any change in pitch, or rather character of the sound, when I tapped it.

BRIDGE AREA THICKNESS

EDGE THICKNESS

UNWEIGHTED DEFLECTION

WEIGHTED DEFLECTION

DEFLECTED SOUNDBOARD