Engelhardt upright bass hole

I was recently traveling with my bass and when I got to my destination I saw that there was a hole on the side of it. It is about 3/4 inch puncture from a bolt on the door of my travel trailer. Is there a simple way to fix this?

Thank you
Stew

Stew,
    The problem created by a hole in the side is weakness, the possibility that the hole will continue to grow in response to future stress. This problem is solved by bending a piece of wood that, when glued on the back side of the hole, inside the bass, will cover the hole and extend about a half inch in all directions from the hole. As soon as the hole has been stabilized and reinforced by this patch, the problem has been solved. Whatever you do to fill and finish match the hole is purely cosmetic.

    The main trick is to find and retain the wood that got knocked out of the hole. It may be tented in or hanging from threads or it may be rattling loose inside the bass. Anyway, the punched out wood has the original finish on it. The less finish matching that you need to do, the better the repair will look. Englehardt basses are made of plywood, three layers of wood with the center ply cross grain to the top and bottom plies. Plywood does not crack cleanly along grain lines. The edges will need to be shaved and refit into the hole. Missing wood must be replaced with matching wood. The patch and the new wood must be clamped to hold them in place while the glue dries. In order to use a standard deep throat clamp for that job, the top would need to be removed. Plywood tops tend to come off in pieces because the glue that holds the top on is somewhat stronger than the glue that holds the plies together. So, we use "luthier's clamps" to work through the side. These are clever little L shaped pieces of wood with a guitar tuner on the upright and a string hole in the foot. We run a guitar string through a plastic block, through the patch, through the hole in the side, through the hole in the sole plate of the clamp, then around the tuner. As we tighten the tuner the plastic block squeezes the patch into place. We also use super magnets to do the same job.

Steve Mason