I have also used the fitting with spring experience on a smaller scale. Cracks on old cellos (and sometimes new) have a tendency to sink ….typically due to the enormous string tension down on the thin,soft spruce top. I often fit the spruce cleats like little bass bars pushing up to restore the arching at the area of the crack. It also works to counteract the tendency for the crack to sink over time. These cleats are fit with chalk as a transfer with a slight arch in the center -( the amount of spring varies with each different repair) and the two clamps together with the hot glue can add just the right amount of force to help me make the crack (eventually!) disappear.
