Repair And Restoration
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Cracked x-braces on Guild F20
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Cracked x-braces on Guild F20
Looking for some advice on a repair for a 1966 Guild F20. The guitar top is significantly depressed (bowl shaped) around the sound hole. This is due to both upper x-braces being cracked as they tuck under the purfling. Also, the bridge is starting to pull off. Any suggestions on sequence of actions? Specifically, should I try to flatten the top area above the bridge and around the sound hole prior to fixing the x-braces? Would it be easier to do that by removing the bridge first (especially since it needs to be re-glued)?
Thanks in advance for your recommendations.
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8 Replies
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Hey, can we hop on a zoom call, chat about this and record it and put the recording here ?
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@ianloothgroup-com Many thanks for the consult on this.
Any other experiences with a similar repair? Also any thoughts on whether the braces on this 1966 guitar were glued with hide glue or other?
I’m still scratching my head about the root cause of the problem. There are some white mineral deposits inside the top going in a couple of inches that may indicate that the top was exposed to water for an extended period.
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Is the X brace loose in any other spots. Like at the bridge plate ? You might have to push on the top to find out.
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Just did a top flattening on a 1964 Gibson D45 12 string that had an extremely sunken/bulged top and loose braces much like your situation. It had loose, but not broken, bracing around the bridge sound hole location. I went for the whole enchilada instead of just going for a standard “belly repair” of just the bridge area because the sound hole/bulge areas were so depressed/bulged. The sound hole area was 1/4″ lower in the middle of the top then at the sides. The bulge was 1/4″ above flat behind the bridge from the sides.
My plan was to heat (larger version of using a heat plate on bridge plate) the effected areas of the top so as to let the brace joints in those areas slip, while raising and lowering by interior jacking and exterior clamping with cauls.
I hydrated the box for two weeks so as to add moisture to the wood as well as the glue joints thinking that this would help bracing joints slip as well as soften wood bracing wood ease to new shape and to help to maintain desired shape when cooled (I watched Bob Taylor’s vids on hydrating. Amazingly, the top flattened half way to the goal I had set). After this operation, I was going to check in case of needing neck reset. It didn’t. I have pics and can explain how and what I did if your interested. The action on the guitar was 3/8″ before the repair. It looks like the action is not too bad on yours? After the repair, it’s still sitting at 4/64th’s at the 6th and 3.5/64th’s at the 1st after two months.
It worked great. The customer let me go for it because it was a wall hanger otherwise.
I know that others have fixed by taking the top off and re-building but I wanted to see if there was a way to flatten without top removal/rebuild.
Like Ian, I suspect that barring any impact to the top, string pressure and the bridge pull broke the bracing and I suspect that’s why the brace glue joints separated on the guitar I worked on. I have seen this situation on another old Gibson where All the top bracing had pulled away at the sides like yours. Since that guitar was set up OK, I did what Ian suggested and wedged the ends. I was afraid that if I tried to clamp the joints tight, I’d blow out the top, side joint. I think I have pictures of that. The 12 string was much more extreme. If you go for flattening the top without top removal, I’d leave the braces broken for now as they aren’t putting pressure in those areas and would inhibit the flattening process and glue them after the top is in position. That’s what I did thinking they’d help hold the top in it’s new position instead of fighting the top back into old position. And I removed the bridge and bridge plate thinking that they would fight to keep top in those areas from flattening.
I love these help vids Ian’s doing and how he would handle things. Great idea!
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Tony thanks for sharing this example. Your work really paid off!
My top deflection is about the same (1/4″ at the sound hole). It’s interesting to me that you took the bridge plate off. When I reach inside it feels like there is a bend at the midpoint running along the length of the bridge plate. In addition, the bridge pins are inclined in the holes (they lean towards the lower bout). Is this normal?
I’m tempted to take the same approach as you did but would prefer to attempt this only if it was originally glued with hide glue. The thought of having to clean up a bunch of old Titebond is not appealing. I may remove the bridge and see what glue is under there.
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More pics……
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Pic of area behind bridge after repair. The gap is 1/16th+ below flat. It was dead flat after guitar was strung up. The same thing in the front of the bridge. The gap was 1/16th+ above flat. I lucked out and guessed right.
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