Archive for month: July, 2013

blockless neck conversion and restoration

23 Jul
July 23, 2013

This was a demanding project involving a large South German bass with “blockless” construction and an integral bass bar.  The bass was in rough shape and had suffered through many of the typical amateur repairs.

First we started with the top, repairing all the top cracks, then we planed out the integral bass bar and judiciously took out extra material in that area until both sides of the top were symmetrical. A bass bar was fitted,  edges replaced to widen the top and the table edge was patched with half edging all around to reinforce  the new edge replacement and correct the use of wood putty that was used to fill in craters around the plate edge.

For the back, the button area was glued together using the aid of a plaster mold, and an inlayed patch reinforced the break. Then the ribs in the upper bout were joined to the back again and a spruce neck block was fitted and glued in.

Someone had inexplicably  used a rasp to work down the ribs so we built up the rib height in the lower bouts with bent quartersawn maple stock,  joined with a simple square edge joint.  That was reinforced with new inside lining.  Also,  rib height was added in the C bouts due to sagging and large doubled rib patches were removed, allowing for reinforcement of the rib cracks with small cleats and linen strips.

Before the top was glued on we decided on a final string length, neck overstand, angle and bridge height.  The string length was taken down from an impossibly long 44 3/16″ to 42″.  A new German machined carved neck was installed (the original scroll was unusable) and finally we finished things up with the setup and varnishing.