Separating neck repair? seeking advice please

[mellowgerman]

Hello, LTG tech shop friends! My beloved 1962 Gibson EB-0 had a neck repair decades before I owned it. It was never a pretty repair, but seemed totally solid, smooth, and stable.... however, a few months ago I noticed slight hairline finish cracks developing on either end of the old repair, starting up by the nut. When I took the bass out of the case last week, I noticed the seam/crack had now extended all the way around the repair. It seems the headstock is pulling forward with the string tension and the repair may be separating. However, applying a little bit of pressure, I am unable to get the seam to open up. My go-to luthier here in the area said he won't be able to repair it before the seam actually opens up. That said, there is essentially a tiny ledge all the way around the repair joint, where the headstock side of the repair is ever-so-slightly higher than the neck side of the repair. Have any of you seen something like this before? I know an improperly done repair can come apart over time, but again, the seam doesn't actually appear to be opening, just lifting slightly... almost like the headstock side wood had expanded a bit? Could that be the case due to humidity changes maybe? Perhaps the glue joint itself is actually holding strong still? If that was the case, would the appropriate treatment possibly be just having a capable luthier sanding it flush again and touching up the finish? Normally a showing repair seam doesn't bother me at all, but since this can now be felt under my thumb as I'm playing, it's really distracting and somewhat hindering to smooth playing in that area on the neck. What do you guys think? Any recommendations would be appreciated! I am happy to pay for a repair as necessary, but would of course be helpful to know what might be going on there in the first place, to get a better idea of what I'm up against here. Thank you in advance!

 

[chazmo]

Yikes, looks like a terrible repair right along the (clean) break of the tongue joint. A good luthier or woodworker should be able to separate that off (with heat? depends what was used to join it) and then make a clean repair.

It really doesn't look that bad to me since it was originally a clean break... But, I've never tried anything like that personally.

 

[mellowgerman]

You bring up a good point. Heat (just as much as humidity) may be part of what is causing this movement. Over the Summer I was using this bass more than my Guilds, since this one is already a roadworn, modified beast, but also because of how resistant this massive thick neck typically is to heat/humidity changes. Our band often had rehearsals in an open garage full of Florida Summer air. We also played a few 3+ hour outdoor gigs, for which I would typically bring this one. I always transport it in a perfectly snug, contemporary (non-original) hardshell case, inside of which the headstock and tuners do not make contact with anything. So it's highly unlikely that it took a physical hit that could have put stress on the glue joint. I never leave instruments in my car during mid-day FL sunshine and heat (I'll carry it with me to avoid this, if need be), but sometimes it may have been in the trunk for a few hours when unavoidable, but again, in a substantial, new hardshell case and never with direct sun beating on the car.

 

[Christopher Cozad]

There may be less painful ways to obtain a headless Bass...

Many builders deliberately construct their necks using scarf joints (such as your photo shows), and these necks typically endure the tests of time. Your photo shows the result of an obvious glue failure. Why? A common cause is a "starved" joint, where the wood pieces are clamped much too tightly together when they are assembled, squeezing out too much of the adhesive. Everything is fine until one fateful day when, "Pop!" the joint begins to separate. Another cause is an insufficiently cleaned or prepared surface. The two pieces must mate perfectly, and any surface contaminates and/or irregularities must be made non-existent. As already mentioned, humidity plays a role, especially if two pieces of wood being joined together have two distinct levels of moisture content and/or movement potential (One piece swells or shrinks slightly more than its corresponding mating piece and, "Voila! Pop goes the glue joint).

 

[mellowgerman]

Yeah, I assumed that the most likely scenario here is indeed that the joint is separating and it will need to be re-glued eventually. I suppose I may have just been hoping that there could be some phenomenon that I haven't heard an account of yet... maybe something like "oh, that's clearly just a case of Coulomb-Inversion where the fibers of one piece of wood try to mirror those of an adjacent piece of wood, elongating, shrinking, changing color, or swelling; thereby creating a mysterious type of electrical bond that boils the moisture out of the surrounding air, creating the illusion of a loosening repair joint. If it remains static through the next season change, you can simply sand the ridge down to a smooth surface again, spray a lil finish and good as new!"

No problem though, if the general consensus among builders/fixers/luthiers is that this will have to be re-glued eventually, I'm okay with that too! I just want to determine what's best for my trusty old steed.

 

[wileypickett]

First thing is to loosen the strings (if you haven't already) so string pull doesn't make a precarious situation worse. Then get it to your repair person.