Takamine woes

[Grahame Myers]

This came into the shop last week, and today I got round to taking a precise look at the problem: A Japanese Takamine 12 string, about 15 years old, with top cracks on both sides of the fretboard extention (pics underneath)
I've done this job a few times in the past, but in this case I'm a little uneasy, I have the feeling that I'm missing something, but I don't know what.
What I mean is, normally this occurs after after the guitar has been allowed to get to hot, by being left in a car in summer for example. The owner (who bought it new), is adamant that he's never done that, although he did tell me he played it a lot around campfires, also in the evenings on the beach when it gets a bit damp and chilly (here in north Germany anyway) Could it have got too warm sometime? Or could this be a case of cold creep over the years? I have no idea what Takamine could have used for glue back then, the only thing I'm sure about is that it's not hide glue. Apart from that, your guess is as good as mine.
The neck joint appears to be OK, as he brought it to me the action was still OK, but the intonation was off, I think due to the fact that the fretboard extention has shifted slightly towards the bridge.
My plan is to remove all the relevant braces, working through the soundhole with a hot thin knife, pull it back into alignment using clamps (Frank has a good example on his website), and then re-glue the braces. And then finally,extra braces at 90° to the cracks to give them a bit of extra strength. It won't be pretty, but plenty strong, it shouldn't affect the tone, as the top doesn't move much forward of the soundhole anyway: Being a 12 string it's heavily braced, and a few extra cleats won't make a world of difference, at least that's my theory which I'm sticking to until one of the steely aces here corrects me.
Anyone have any thoughts on this, or have I missed something ?

Grahame

[Grahame Myers]

What I forgot to say in my first post is, the main reason for my puzzlement is that all the braces are well-glued, and show no signs of movement in the past, I still think I've overlooked something really obvious...but what?

Grahame

[Paul Verticchio]

It is curious, but I've seen this a few times over the past 44 years of playing.

I therefore offer the following possibilities more from the POV of a gigging player as opposed to a repair tech:

Does the guitar have a hard shell case? If so, does the case have an arch in its top or is it a flat top case?

If the case (hard or soft) has a flat top, it looks to me like an occurrence of dropping something heavy on the case in the neck joint area.......or....

If the case has an arched top, I'd put my money on a backward fall either in or out of the case. Since it's not a Gibson, the headstock &/or neck didn't fracture.

In either event, the overbuilt properties of early 90's Tak's allowed the heel and neck block to survive intact, but transferred the energy to the soundboard and that's where I'm laying my bet.

As far as your customer's denial of overheating, I've never had a client admit that they ever dropped, hacked or otherwise abused or neglected their instrument (; I perceive them as not so much being deceitful; but simply embarrassed.

Best of luck Grahame (:

[Grahame Myers]

Paul
Nice of you to reply, and your thoughts are very interesting, you have given me new aspects to concider (and worry about) :-) The guitar does have a hardcase, from Takamine, I assume original. The guitar seems to fit well in the case, although I admit I didn't pay particular attention to it until I read your post. I'll take a closer look tomorrow when I go to the shop.
After looking at the photos I put up, what do you think of my plan of action? It seems to have only one brace perpendicular to the cracks, the main one just in front of the soundhole, and that is really BIG. Takamine overkill :-) I thought if I deglued the brace, I could try clamping it up till the cracks are flush, and then reglue the brace back in. And then a couple of reinforcing cleats at the ends of the cracks under the soundhole. I hope it works, the other times I've done repairs like this, it was much clearer what was wrong: the braces were loose, or completly missing. In this case, all the braces are well glued, it all looks great, except for the cracks on both sides of the frettboard. Hmm, tomorrow I'll know more...
Btw, I was a bit surprised that nobody else has any thoughts on this, so maybe I'm worrying about problems that don't exist....

Grahame

[Paul Verticchio]

Hi Grahame.

Your proposed plan of attack is 100% sound as far as I'm concerned.

Structurally, it will offer a stability enhancement over the stock design...as in: it should be "better than new" when you complete the repair. It also is getting logged in my data book as an elegant solution should I run across a similar situation in my future.

Just out of curiosity, how much pitch or wobble does the neck demonstrate when you apply downward pressure on the neck to realign the top?

I'd imagine that zero to very little flex or cantilevering above the sound hole between the FB extension and the sound hole (when applying pressure) would indicate a potential for complete success. Just realign and reinforce per your plan.

The audible effect of the repair will have an insignificant to zero negative impact on the sound of the instrument.

Possibly the most difficult part of the repair will be the finish touch-up given that the finish is most likely poly.

Fortunately, our host Frank is the top cat for the final "blessing" of your plan. I hope he has the time to offer his opinion.

As far as your being overly concerned with the issue; I figure that since it was most likely caused by an acute force pressure trauma, a pre-existing structural flaw shouldn't be of concern at this stage.

Again, very best of luck and hope you will post your results.

Have a great week (:

[Grahame Myers]

Well, I must be honest and admit that Frank has already been there and done that (and probably has at least two t-Shirts too :-)) Here: http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Structural...
That's what first gave me the idea, but in my particular case I was a little bit uneasy, because it all looks so good, except for the cracks on both sides of the fretboard. I originally had planned to start today with the job, but yesterday I saw a car that I've fallen in love with, I'm gonna see if I can trade my old one in against it , if possible this week. You know that feeling, when grown men become little boys again: I must have that car, I want it now :_) Wish me luck! As soon as I get into the job, I'll post some pics up here. Have a good week, and thanks for your help up until now.

Grahame

[Grahame Myers]

Paul
You wanted to see the results, here they are: The job went quite well,although I didn't manage to completly remove the main brace, the one just in front of the soundhole. I don't know what glue Takamine used on it, but it sure is tough stuff. In the end I just seperated the brace from the top left and right of the cracks, figuring that'd be enough to let the top move back into position. Then I clamped it up for 5 days, making the clamps a bit tighter every day, after 5 days it didn't seem to be moving any more, so I glued the main brace and clamped it up, leaving it clamped down to the bench to stop it moving back before the main brace was set. After waiting 24 hrs I removed all the clamps, and then fitted and glued spruce cleats at 90° to the cracks, just behind the soundhole. You can just see them in one of the pics below. Then I flooded the cracks with CA, as the customer said he didn't care what it looked like, as long as it held. This Takamine is now his campfire beater, as he bought a new Yamaha 12-string a few weeks ago. Seems to've turned out well, and was an interesting job. Önly time will tell if it'll hold up long-term. I hope so, I told him if it moves again, the next repair is on me!

Grahame

[Paul Verticchio]

Grahame,

Thanks for the results pictures.

Very nice work and good looking CA drop fill work, especially since you didn't do major touch-ups.

I don't think you'll be seeing that guitar with the same problem again. Plus, if that's a campfire beater, well, he sure has a well repaired one.

OT: in another post I believe you stated you are recently retired and have a background in IT. Me too. I retired from a my "day gig" career after 33 years and am just beginning to get increasingly busy with my guitar tech services. Actually, a little busier than I'd like right now as I'm also a working player. Thank heavens for understanding wives....and pensions (:

Cheers & the VERY BEST of luck,
Paul