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PostPosted: Mon Sep 09, 2019 1:16 pm 
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Mahogany
Mahogany

Joined: Tue Dec 22, 2009 5:40 am
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First name: maarten
Last Name: van guyse
City: heusden-zolder
Zip/Postal Code: 3550
Country: belgium
Focus: Build
Status: Amateur
I haven't posted here a lot, but I have been following this forum for along time. I hope it's OK to ask for some advice on a repair that has come onto my workbench. I would be very grateful for any advice on how to proceed.

The guitar is basically decapitated, leaving very little in the way of long grain to work with for repairing. The headstock just snapped off, breaking almost all fibers in the wood. I never saw this before, really.

I currently see 3 possibilities in dealing with this:
1) aligning the headstock as well as possible, and routing out trenches for filler/reinforcement strips. Won't be pretty...
2) removing the current headstock and replacing the scarf joint with a V-joint, and making a completely new headstock for the guitar. Of course I would lose the headstock decal in the process. I have done V-joints on a few of my classicals, but never on an already finished neck. I can think of many (potentially disastrous) problems arising from this approach, yet this somehow seems like the best option to me,structurally.
3) walk away from this one. This option is growing on me, I must admit.

Any opinions/advice offered would be greatly appreciated.
Also, the question comes up as to how much one would charge for this type of repair... This is not your typical setup job,right? Any pointers would be appreciated as well.

Many thanks in advance!
Maarten

a few pictures of the damage:

Image

Image

Image


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PostPosted: Mon Sep 09, 2019 1:37 pm 
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Koa
Koa

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First name: Ernest
Last Name: Kleinman
City: Guthrie
State: OK
Zip/Postal Code: 73044
Country: United States
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Status: Professional
My 2 cents from doing a headstock repair like this , it can be done. But ? the cost in time and money for owner would be significant. Some owners have sentimental attachments and will pay . Others are more pragmatic, an will pass. It all depends on your skill level and how hungry you are for work IMHO.


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PostPosted: Mon Sep 09, 2019 2:05 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Jan 28, 2008 5:21 am
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Location: Central PA
First name: john
Last Name: hall
City: Hegins
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I have done many of these. Not a big deal but what I will tell you is that you need a few things to do this well.
The first thing is remove all the tuners. Now there will be some that disagree with me but I can tell you the first thing you need to do is get the right glue for the job and Hot hide isn't it.
I use west systems epoxy and 206 hardener. This is a 5 to 1 mix and takes 24 hr to cure so do this.
A mix your epoxy and get some UHMW nylon or at least wax paper and a good flat piece of 3/4 in plywood.
Lay the wax paper and ply on the next side of the break and clamp . Do the best you can. Now take the epoxy and put some on both surfaces.
You can test fit first and remove splinters that are holding off the mate. Now apply the epoxy and beware that you don't want to epoxy your block on the next so use wax paper and apply wax to your block set the 2 pieces together and apply a clamp stop on the block and use that to take 2 wedges to hold your 2 pieces together as it cures. Also clamp flat once you have the joint closed.
Day 2
now open up and see how secure it seems. I would now remove the head veneer and put in 2 splines . Fiberglass or carbon fiber would be my choice. 1/8 by 1/2 should do the trick and epoxy that.
Day 3
You can then allow that to cure and put to splines on the back of the neck, of mahogany and epoxy.
Day 4
sand stain and finish. You should have a solid repair. and replace tuners and string up.

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blues creek guitars
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PostPosted: Mon Sep 09, 2019 4:15 pm 
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First name: Chris
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It can be done, but it's a pain in the hindquarters. Do it and be a hero.

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PostPosted: Mon Sep 09, 2019 6:28 pm 
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Cocobolo
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Joined: Fri Jan 15, 2016 9:04 pm
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First name: Andy
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Agree with John Hall. I've done a few of these. I'll just add that if you want to minimize visibility of the repair, you can sand back the brown on the back and sides, and blow translucent color back on with TransTint and lacquer. The spray-on finish, translucently, will allow you to darken and get a close match, and a great blend at the back of the neck. You can effectively minimize any visual presence of repair. Also another trick is to flatten the bare top of the headstock, remove just a bit of material thickness, and thicken up the headstock "veneer" for some added strength. You might get enough strength that way to not require splines, but John's procedure does not add much work and is most prudent.

One point on your initial "long grain" comment. This break is not really a butt joint glue-up. If you can line up the pieces well, there is a tremendous amount of glue-up surface area in the hundreds of fingers. Structural epoxy will give an excellent bond in that application, and provide some sheer support where everything is not picture perfect in the glue-up joint.


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PostPosted: Mon Sep 09, 2019 6:34 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 6232
Location: Virginia
On a Sigma though? That guitar is history imho.



These users thanked the author jfmckenna for the post: Ken Jones (Tue Sep 10, 2019 6:18 pm)
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PostPosted: Mon Sep 09, 2019 9:15 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Dec 14, 2007 3:21 pm
Posts: 3287
Location: Alexandria MN
I have never seen a break just like that. With the great advice given in this thread, if a Sigma came into my shop like this one I'd do it in a heartbeat for a nominal charge just to get the experience on a low value instrument.

If I had already done a ton of them more $$$.

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PostPosted: Tue Sep 10, 2019 12:59 am 
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Mahogany
Mahogany

Joined: Tue Dec 22, 2009 5:40 am
Posts: 40
First name: maarten
Last Name: van guyse
City: heusden-zolder
Zip/Postal Code: 3550
Country: belgium
Focus: Build
Status: Amateur
Thanks for the advice guys!

I wouldn't have considered epoxy for this repair. But coming from you, John, I'm sure it's right. I do have west system epoxy 206 on hand, so that should work. I have made a little sketch of how I understood your advice. Is this more or less what you meant? (I'm not really sure what you mean by 'next side of the break')

Image

Another thing I'm concerned about is finish repair. I normally do French polish on my guitars. I'm kind of hoping this would work over this laquer. I'm not sure what type of laquer this is, probaby some sort of poly,I would guess.

Again, thanks a lot, greatly appreciated!


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PostPosted: Tue Sep 10, 2019 1:08 am 
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Brazilian Rosewood
Brazilian Rosewood
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Location: Taiwan
First name: Tai
Last Name: Fu
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Focus: Repair
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There's nothing wrong with using epoxy on a headstock repair. Nobody generally is looking to separate a headstock joint so using a heat/water resistant glue isn't a problem.

Glue it up, then reinforce it with filler strip if you have to. Then do a tint or black burst over it (I suggest black because it hides the repair completely).

It depends on the owner's budget. If he has a low budget, glue it up and clean it up the best you can.

If he's willing to pay a little, then reinforce/refinish it.

If he says do whatever it takes, spare no expense, then make a V joint.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com


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PostPosted: Tue Sep 10, 2019 8:06 am 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 6232
Location: Virginia
Shellac will stick to anything so go for it.


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PostPosted: Tue Sep 10, 2019 10:46 am 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Jan 28, 2008 5:21 am
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Location: Central PA
First name: john
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Country: usa
Focus: Build
Status: Professional
you got it correct warmong
when I started in this business I lived close enough to Martin and I would get all the sigmas that were rejected or ship damage. I ct my teeth on fixing them. I agree that in most cases this is a $75 to $100 repair takes about 1 to 1 1/2 hr to do. Sentimental guitars are often the most rewarding repairs to being back.
If the break was a clean one then still used epoxy but the splines won't be needed.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it


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PostPosted: Tue Sep 10, 2019 10:50 am 
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Brazilian Rosewood
Brazilian Rosewood
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Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
Do Martin commission factories in China to make Sigmas? I see them in guitar stores in Taiwan right next to Martins, and it's VERY hard to tell them apart without a close look.

All the ones I see have terribly high action, likely badly bellied soundboard.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com


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PostPosted: Tue Sep 10, 2019 11:21 am 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Jan 28, 2008 5:21 am
Posts: 4837
Location: Central PA
First name: john
Last Name: hall
City: Hegins
State: pa
Zip/Postal Code: 17938
Country: usa
Focus: Build
Status: Professional
not anymore
sigman name was sold and has nothing to do with CF martin anymore

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it


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PostPosted: Tue Sep 10, 2019 11:26 am 
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Brazilian Rosewood
Brazilian Rosewood
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Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
Someone told me it used to be a German company that made great guitars, and then someone sold the name to a Chinese company, and they're basically making junks now.

I'm not saying China can't make very high quality items, they absolutely can and they have the precision to do so, but people contracting them to make stuff aren't telling them to make anything of quality.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com


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