Repairing a brace with a warped top

[abelanger]

I have an old Korean War-era Korean built Cameo 12-string guitar with a brace that came off long ago and a top that is now badly warped. The 2 luthiers I spoke with didn't want to fix it, said the glue would just come undone again (and who wants to use a luthier who tells you in their experience the fix would just come undone anyway?)

For me, this guitar has great sentimental value as my grandfather gave it to me. So I am committed to fixing and playing this again. Is it possible to fix? will enough humidity fix the warped top? or will that amount of humidity just unseat the top? is it wrong to just leave a cross brace pillar inside the guitar? it's not a martin and will never sound like one, so I'm not looking for perfection here.

[Fathand]

If the pillar makes the guitar playable so you can keep it for sentimental reasons it is not wrong as long as you are ok with how it sounds and plays.

I'm thinking those "luthiers" know a fix is probably not cost effective but it looks like hide glue so it should be fixable if you can afford it.

[Henning]

They certainly didn't exactly save their glue, but rather were very generous with it. Could very well be hide glue. Then you "just" might manage with heating it and pressing the joint. "just" means, reaching in to the joint and perhaps spray on an amount of hot moist there; not too much - neither too little. Immediately pressing it afterwards which can be made with a stick that fits exactly between the back and top, leaving some pressure on the loose bar to close the loose bar to the top. Be certain to spread the pressure of the stick over a larger area of the back with a piece of veneer or similar. Let it dry. If you can get a small piece of glue out of the guitar first you can find out if it really is hide glue. If it loosens up in water or gets sticky with water, it most likely is. You might use some sharp tool as a knife or similar to get a small amount of that glue out where you see it has been flowing. If it is hide glue, you can scrape it off to a powder. Try to first find out if it is HG, it will make it a lot easier.

[abelanger]

Thanks. I don't know if that glue is original or from a repair somewhere along the way... I'll test it as you say. My plan was to scrape it all off (as much as possible) and use fish glue, adding a permanent "pillar" near the side wall, perhaps tension only in case i want to remove it easily (if it looks like it might stay, or with minimal glue)

I think you're right about those luthiers, but the top IS warped so i do believe that glue alone won't cut it.

[printer2]

What does the outside of the guitar look like? Offhand I would say removing the back and removing the bad braces from inside and then straighten the top would be the way to go.

[abelanger]

If I knew how to take off the back I probably wouldn't be on this forum! This will be my first acoustic repair.

I have brace jacks in there now (no glue yet) and am attempting to steam the guitar to work out the warp. It's not really that bad. And the bridge is not attached to the front, it is a floating bridge attached to the rear side of the guitar so only pressure against the top is perpendicular to the strings, not directly pulling on the top itself. So I'm rethinking... probably don't need to leave "pillars" inside the body. I'm thinking the glue alone should hold it and the luthiers I spoke with simply didn't want the job (or thought the cost they charge would be more than the worth of the instrument) so I'm a little more confident in just gluing the brace back.

Here's a front view of the guitar. Hard to see the warp in a pic though. The red line I drew in the screenshot shows approximately where the detached brace is... I'm using jacks as it is about 8 inches to where I would need to get a clamp. Is that good enough? or should I buy a clamp too?



I tested a piece of the glue (as suggested) by putting it in some warm water. It did not soften at all. So I guess not hide glue? Does it matter what kind of glue it was if i repair with fish glue? and how careful do i need to be about cleaning out the old glue? It is unbelievably difficult working blind through a sound hole upside-down while looking at a mirror through the space that is mostly filled with my thick arm! How do you guys deal with this???

[Henning]

You might have to use some tool to reach all the way in to where you need to scrape off the old glue. Maybe some grinding paper could be used? If it had been hide glue (HHG) you wouldn't have had to clean out the old glue. But it isn't so, as far as I understood it, then all the old glue must off 'til the wood is bare, to make the glue stick to the mating surfaces. It has to be wood-to-wood when you glue. If you can the detached brace in the right position without the use of a clamp, well it is an awkward position, I'd say it is easier to reach in there to close the glue joint with jacks.

Perhaps you can find some inspiration from this link: https://hazeguitars.com/blog/loose-guitar-brace

[Henning]

Stewmac has some good advices in lots of cases:
https://www.stewmac.com/video-and-id...-loose-braces/