A mandolin repair
Loose Sides
© Frank Ford 2010; Photos by FF
You might get the idea that this is more of a "tool article" than one
about repair technique, and I suppose that's what it is.
Here's the problem - a "teens" vintage Gibson mandolin with some glue failure at the joint of the back and sides. On both bass and treble side, there is a gap a few inches long, where the lining broke from the back. Unfortunately, the sides then moved inward, leaving a bit of an overhang that's easy to see and feel:
The difficulty in doing this repair is being able to push the sides outward from the inside with some force and accuracy. I tried using a stick to push from the inside, to no effect. So I dreamed up this rig to allow me to push as hard as I wanted while maintaining good control:
It's a simple steel scissor affair with threaded holes in one end, into which I can screw push rods of any length, and a screw mechanism to apply force and hold position at the other end:
The most important feature of this device is the ability to insert both halves independently - otherwise, it would not be possible to get enough length inside. Here's the first leg going in:
And, the second one:
Once I screw the pivot in place, the setup is complete:
After poing around for a while, I was able to get the ends in place so I could push the desired part of the side outward:
With the scissor in place and tight, I could feel that the side was realigned perfectly:
Then, with some nice hide glue squished into the crack and clamps applied, the repair was done:
I have a feeling I'll be making up more of these pusher tools in the future for other instruments. . .