JRJ - Instruments
James R. Jennings

String Bass: 1942 Kay

General description:
Completed bass - front view Completed bass - back view Completed bass - side view (left) Completed bass - side view (right) View of F-hole View of the paper When it was manufactured, this was a nice blond Kay bass. By the 1970's the neck had come loose from the body and it had developed separations between many of the plys, especially on the edges of the front and back plates. The junction of the neck to the body was repaired about 30 years ago, but by 1998 had come loose again . As a consequence, the nut was pulled forward by the tension of the strings, which raised the action to the point that the bass was virtually unplayable. The failure of the bonding between individual plys also became progressively worse. It not only affected the resonance of the plate adversely, but also seriously reduced the mechanical strength of the edges of the front and back plates Because of this, a lot of small pieces broke off of the edge, particularly where it made contact with the floor when the bass was set down on its side. The addition of bondo to some of the places where plys had broken out did nothing to improve either the resonance or the structural integrity of the instrument. All of the photographs* show various views of the bass after the repairs were completed.

Neck and Scroll:
Completed bass - Scroll (left) Completed bass - Scroll (right) Completed bass - Heel of the neck (Left) Completed bass - Heel of the neck (right) The repair was begun by removing the neck completely from the body. This process actually turned out to be easier than originally feared, because there proved to be very little holding the neck in place. Once the neck had been removed from the body, it became possible to see that a small piece of the neck block had split off from the rest. It appeared to have split apart many years ago and then been poorly glued back into place, perhaps more than once. Whether the split was responsible for the failure of the neck was not clear since there appeared to be a sufficient amount of undamaged wood to hold the neck in place. In any event, the fit of the neck was very loose.

The broken piece of the neck block was cleaned up and glued back into place, but the glue was not regarded as sufficient to hold fast against the pull of the strings. However, because the fit was so loose, there proved to be sufficient room to put a small shim into the dovetail between the neck and neck block with the neck. The shim was placed with the grain running perpendicular to the grain of the neck block, thus providing a great increase in strength as well as improving the loose fit.

When the neck was glued into place, a wedge-shaped shim was placed between the base of the dovetail and the base of the neck juse beneath the fingerboard. This prevented the neck from being pulled forward into the gap underneath the base of the neck when tension was applied to the strings. The scroll on both sides was found to be loose at the edges, and additional glue was worked in underneath to stabilize them. They were nearly complete, however, so it was deemed inadvisable to attempt further repair.

Separations of the plywood:
Completed bass - edge view Once the neck was glued securely in place, the slow process of repairing the separated plys was begun. This turned out to be a much larger job than originally anticipated, because there was separation essentially everywhere along the edge of the plywood (including the f-holes) even where the wood was not broken away. Fortunately, the separations were only along the edges and did not involve the interior of the wood. One by one, the plys were spread apart enough to allow glue to flow in between them and were then clamped in place. Once the plys were together again, the edge was built up to approximately the original shape using small fragments of wood bound together with glue. A coat of sealer was placed over the finished bass to protect any exposed wood from further degradation. It was deemed particularly important to prevent air and moisture from reaching the margins of the plys in order to prevent them from coming apart again. On the other hand, wherever the original finish remained intact, it was not disturbed.

*Photos on this page are courtesy of Fredrick J. Wild.

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