1914 Gibson Harp Guitar back shrinkage.

[Eron Harding]

I've got a 1914 Gibson Style U Harp guitar that the back has shrank up so much you can't match the sides back with the top.  I'm scratching my head on what do do with this.  The back is loose from the end block and the sides.  It's doing the same thing around the upper bout scrolls also but not to this extreme... yet.

Any Suggestions?

thanks in advance.

[Frank Ford]

It can be possible to press everything back in place, and sometimes it pays to take the back off completely.  Regardless, it's a nice big piece of work.

Check out my "bench clamp" article to get some ideas about that:

http://www.frets.com/FretsPages/Luthier/Tools/BenchClamps/benchclam...

[Eron Harding]

Thanks Frank, I actually have some of those bench clamps being made up now, and that's my current plan of action.

  I'm just worried I won't be able to push the sides back in without the sides breaking, and trying to put together a Plan B.

Should I expect the bench clamp resolution to take some time?  as in tighten the clamps a little more every day?  Your not talking about going the full distance in one take so-to-speak....

[Ned Knepp]

Have you humidified the guitar? 

[Eron Harding]

Yes, I humidified it for a month previously.

[Greg Mirken]

The reason humidifying hasn't improved the situation is that the back has not shrunk so much. Wood shrinks very little along the grain compared to across the grain, which would affect the fit at the shoulders and hips of the body, but not down there. String tension over a period of time with the back loose has splayed the side out and caused your misalignment. Slowly coaxing the side back into alignment is the right course of action.