Repair method for bracing coming unglued ?

[Boneman]

so I went for a string change on my JF30-12 and noticed a peculiar issue.

The top seems sunken in a bit between the bridge and the soundhole. Weirdly it’s just in front of the bridge, behind the bridge the top is opposite, has a nice arch.



I ran a straightedge across the frets to the saddle and it hits just above the top of the bridge, so maybe the sunkeness did curl the front edge of bridge in towards the soundhole?. Though looks like the bridge is flush across the top in front and back, might be starting to lift on the back, hard to see for sure. kinda looks like glue fibers stretched a bit on the bass side.


The top behind the bridge is opposite, arched as one would expect, but in taking the photo, the photo showed what looks like a crack in the finish there at the center seam, not really visible to naked eye, but if I scratch across with my nail I feel it, so suppose’n got to keep an eye on that.


Next I decided to look underneath with an inspection mirror and noticed what looks like the brace maybe starting to come unglued:

Question is how would you fix that? Or is it nothing to worry about? A squirt of glue and clamp it, or get it to a luthier?
Anyone know a good luthier in So Cal? I mean I don’t want to trust it with anyone, and not opposed to even maybe a shipment out to Mr. Fixit.

Thanks in advance for any useful advice.

 

[SFIV1967]

Ralf

 

[Boneman]

Perfect, that’s what I needed , thanks Ralf

 

[chazmo]

@Boneman good that you caught that... Fix that (or get it fixed) right away. Immediately slack the strings and get the guitar into a high-humidity environment (cased with many dampits in the soundhole for a week or so).

 

[davismanLV]

Not sure if it's addressed in the video (haven't watched it yet) but critical will be using the right kind of glue. Can't really get the old glue off in there, and most glues won't adhere glued surface to glued surface. That's all I got for ya. Love the maple. Good luck with the repair!!

 

[davismanLV]

Wow, that's crazy the tools he comes up with to get the old glue off and inject the new glue in there!! Great video with the clear top so we can see what's up!!

 

[Boneman]

Agreed Tom, but his little tool alone that squirts the glue is $100! I’m looking into alternative methods, but there’s just an inch long section of that main x brace coming loose to clamp, so thinking a few short swipes in there with a feeler guage to clean out old glue, then a q-tip with titebond on it to mush glue into that section from the side and clamp it against top. If that doesn’t work,

 

[Boneman]

get the guitar into a high-humidity environment (cased with many dampits in the soundhole for a week or so).

I hear ya, and thanks, but to be honest it lives in its case until I play it, (well all my guitars do now, except my one MIM strat) . I keep my guitar room 45-50%RH, and there are usually three if not (4) Boveda 49% packs in the cases.(minimum two in soundhole and one in neck pocket).

Now maybe because I do the above, it hasn’t blown up already. I think it’s maybe been like that awhile, so it seems it might be stable enough? The brace could be warped and may not just glue back easily, hard to say and would hate to make things worse scraping under it

 

[chazmo]

Boneman, no not really, It's not enough, and that is not a stable situation. The soundboard is warped and needs to be put back into shape. Over-humidifying will help but it's only in preparation to getting the brace re-attached.

When I had a friends guitar where this had happened, I over-humidifed for about two weeks and reshaped the pronounced belly on the soundboard by stacking some books on top of the bad area(s). That helped tremendously, and then my luthier reattached the braces.

I would strongly recommend contacting a luthier for advice though. If you keep tension on it is only going to advance the separation.

Good luck, whatever you do.

 

[wileypickett]

What's going on is the the area behind the bridge is bellying up and the area in front of the bridge has responded by collapsing inward.

My JV72 had the same problem when I got it. The area around the soundhole looked like a potato chip and the bellying was the worst I've ever encountered. (Amazingly the braces were still secure.)

I installed a Bridge Doctor, slowly tightening it over a month or so, and keeping the guitar super-hydrated between adjustments. Eventually the bellying disappeared and the corresponding distortion to the top in front of the bridge leveled out significantly, though it never got compelely flat.

Finally I felt comfortable stringing it up again, but I left the Bridge Doctor in permanently. It's been like that for around a decade, and is, today, one of the finest sounding guitars I own.

I suspect your luthier will want to get the top as flat as possible before gluing the braces back. A Bridge Doctor accomplishes that. Whether you leave it in permanently or not will depend on whether the guitar top remains flat under string tension once the braces are secure again.

I'll echo what others have said: slacken the strings and get those braces taken care of. As bad as it is now, unattended it can (and will) get worse.

Good luck!

 

[Boneman]

Quick update, I’ve got my room around 55%:
So I opened the lid to let it breathe it in. Then outta curiosity checked it at guitar level on the floor, to my surprise it’s 10% higher rH there than on the shelf. Soundhole humidipaks may be adding to the rH in the immediate vicinity as well. The sunkenness has receded some, so now on to the next step.

 

[chazmo]

Keep it up, Boneman. More if you can. And be patient. Let the wood absorb the over-humidification and slack the strings.

 

[Boneman]

Let the wood absorb the over-humidification

How long before it becomes too much? I suspect you can over do it yea?

 

[chazmo]

I wouldn't go more than two weeks of over-humidifying, Boneman! I'm sure at some point you'll stop seeing any improvement. Look for that and maybe go a couple more days like that and she'll be ready for fixin'.

There used to be a Taylor video on this. They had/have a chamber for keeping the guitar at high humidity so they can speed up the process a bit. Wish I still had a link for that.