7/10/2012

Workshop: Inadvisable Neck Repair


So, there's a 50's 3/4 upright bass, German-made, hanging around in the workshop for the taking. The only problem is, the neck is split in that typical "Kay break" location, had previously been hack-glued back with white glue and a giant dowel through the middle of it, then came loose and the dowel broke off as well. Add to that 30+ years of sitting in dirt and grime and getting beat to heck and you have this little project.

The first two pics are of the broken-off neck/heel area, but somewhat cleaned up from where they were before. I blew out the joint with compressed air and have been carefully sanding ever since. The problem is that there's wood loss here and there in the break area and the added dowel has slightly changed the shape of the joint. Still, there's workable space to attempt one last repair before it really, truly becomes necessary to replace the neck with a new one (which is what a dedicated bass shop would do right now, seeing the state of this joint).

However, I want to do this on the cheap (and practical).


Here I've started to sand out the surfaces and rough them up.


Here's the top of the massive rosewood fretboard where the big dowel was installed from the top. At least I can be thankful it's a dowel and not a giant bolt, though.


And here is exactly what I would tell someone not to do (please don't do this yourselves! I mean it when I say this is "inadvisable"), but I've gone ahead and done it anyway, because I want to see if I can keep this beater working for at least a little bit longer with this original neck.

Yessir, that joint is epoxied with 2500 psi goop and now has hideous mending plates to reinforce the joint as well. The plates themselves work like additional clamps while the epoxy cures in that the holes for the screws were pre-drilled at the outer edge of the mounting hole on the plates so that when the screws were tightened they pulled the two sides of the break together.

I'm hoping these plates are temporary, since my "down the road" plan is to replace them with grungy old kitchen flatware that's recut and shaped to the heel, rather like some old Knutsen Hawaiian guitars... though, I'm not going to go to the trouble if the instrument implodes upon stringing-up, which it very well may do.

I mean it when I say this is a beater!

1 comment:

Linda said...

Thanks for giving the inside scoop (so to speak). I learn a lot from posts like this one.