One of the distractions I've had over the past few weeks is the repair of a broken Alto Clarinet for one of our directors.
It was bought over from the 'States with a known broken coupling in the body, but until it arrived we didn't know how bad the damage was or whether we could repair it. The value is not huge, about $240, but it was a bit of a challenge...
When we got it home, the broken part of the coupling which joins the two halves of the nearly 3ft body has been glued into one half and broken off from the other. These male/female couplings have a cork seal and are extensively used on musical instruments. As the broken off spigot was actually part of the main tube material, we just cleaned that face off ready for the new ali tube.
The broken off and glued piece was of the same plastic material as the main body, but the adhesive was like Araldite and well cured. The length of the piece was unknown but estimated at about 1.25". The recess for the coupling had to be retained without sustaining any damage.
I couldn't use any mechanical tools as the instrument couldn't be held, and was too fragile.
I ended up using 4-point and 3-point drills to drill out the broken stub, turning the morse tangs with a small adjustable by hand, gradually increasing sizes until I had about 1/16" wall of the old piece left. I then chipped away at that with a tiny screwdriver to make a slot down the length of it to enable it to be collapsed and withdrawn.
That went OK, but took four or five nights of slow work, the body was gripped lightly in the vice with protective material around it. Once the initial bit was out, the smaller locating stub which was further down was treated by opening another slot and gradually working it out.
The original bore needs the remnants of glue removing, and I have to make up an aluminium replacement sleeve that will be permanently screwed into the place where the original spigot was formed and the other end of that sleeve will fit into the stepped recess which has now been cleared out.
The worry about damaging the instrument prevented a quicker but more risky route being taken, but the results have more than paid for the time taken.
Peter
-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info: