Broken Headstock
Copyright © 2001 Howard Coleman (text and images).
This is mostly about choice of glue and gluing tips using the broken headstock job as an example. For an alternative account of this job I recommend you look at Frank Ford's website.
An accident waiting to happen
Bad design left a weak area in this guitar. As the neck is carved from a single piece of mahogany there is considerable grain
run-out in the headstock - an area under great strain. Some manufacturers, eg CF Martin and myself leave a thicker piece of wood
in the shape of a decorative diamond behind this weak area and add a face "veneer" of rosewood or ebony a few millimetres thick.
Preparation
My first thought is to get the parts to fit closely together.
Looking into the break I could see broken wood fibres that had been bent
over. I removed these with an old dental burr scrounged from my
dentist.
Choice of glue
The next thing to consider was choice of glue. Aliphatic
resin glue (yellow wood glue) would certainly do the job but, because it is
water-based, would cause the fibres to swell and might prevent the joint going
together as tightly as it could. Epoxy glue would not have that
disadvantage but is more is difficult to use. Cleaning up the excess
squeezed out of the joint is unpleasant as the glue is viscous, sticky and
harmful. However, I decided to put the guitar first and go for epoxy. Being viscous,
penetration of the glue into the wood would be slow so I chose a slow
setting one - Araldite Precision - to allow sufficient time for
penetration. (Incidentally, Araldite Precision used to be called just plain Araldite
before Araldite Rapid came along.)
Epoxy Gluing Tips
Mix it on an unwanted CD. AOL CDs work fine and are in plentiful supply.
Spring clamps work well with epoxy. As the glue squeezes out slowly the spring takes up the slack and keeps the joint tight.
Use nylon fabric for wiping away excess glue. Paper tissues or cotton will put fibres (lint) onto the surface that are hard to remove.
Last revised: June 10, 2007.