This joint, like many others, is a problem because of the different rates of expansion and shrinking of wood grains glued togather at 90 degrees to each other. The jack flange expands and contracts much more than the wippen rocker. Hide glue is a less than satisfactory glue because of its brittleness as it ages. Wurlitzer finally fixed this problem by putting the bushings in a jack and the bird's eye on the rocker as a hump left after the rocker was machined. Only way to solved this problem is to reglue the joints with a more flexable glue or to allow CA glue to wick into the joint without taking it apart first. One was suggested is to unhook the bridle straps, remove the wippen screws and let the wippens hang on stickers of remove them entirely and test each joint well and reglue those that come apart and replace the wippens. Done wholesale speeds the job. dNewton nhunt@jagat.com
This PTG archive page provided courtesy of Moy Piano Service, LLC