Pictured here is the finished breast patch that has been fit to the top to support the corrected arching.
This cello ( like many very old cellos) had sunk in the bridge area due to the immense strain of string tension over time – and in this case, a loose fitting post that did not provide support to the treble bridge foot.
The first step is to make a cast – the sunkenness will show on the cast as a positive bulge. The cast is then carefully scraped to correct he arching. Then the top is clamped into the corrected mold with heat and pressure for a week or two. The spruce will swell to fit the mold and the arching will be back to what it should be. Then a patch of spruce is fit to support the correction – its then worked down to fit the contour of the top – and in this photo the new bass bar is fit on top – further adding the “strength to endure”
The hardest part of the process is the fitting -with chalk as a transfer- this size of a patch where the surfaces have to fit perfectly – otherwise the heft of the unworked patch will distort the delicate arched spruce of the top. Many books on tap
e go by during this process.
