Headstock Crack Repair

w666

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I just acquired this guitar at a bargain price because of a crack in the headstock. I would appreciate any advice in the room before I attempt to glue this up. As you can see, the crack has not yet separated. This is what the crack looks like under full string tension.



I don't think the crack warrants a splint a la BCR Greg style (although that's clearly Plan B in case the glue job ever fails). I plan to use original Titebond. My question is that since the crack is so thin, how do I get enough glue in the joint before I clamp it up? Titebond is fairly thick....has anyone ever tried to thin it with water? (I'm afraid that it will compromise the bond strength, so I don't even want to try). And I'm afraid to apply more pressure to open up the crack for fear of snapping it off completely.

Left on my own (meaning without any better advice to the contrary from you all ) I plan to use a syringe to get the glue in as deep as I can, and then use a fine thread to try and pull the glue down into the crack (like flossing a tooth). And repeat....

I also thought of using compressed air to blow the glue into the crack, but that seems too messy, so I think not.

My thanks in advance for your ideas!
 

jcsk8

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You'll probably need a more fluid glue that can penatrate on the crack before clampig. If the crack is already in touch, maybe dangerous to force a opening and increase the cracking.
Maybe you should just leave this way. If under string tension is not bigger, or loosing tune.
 

TravisW

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I've thinned Titebond I with water and syringed it into a narrow crack. Titebond recommends no more than 5% water for thinning - can't remember what percentage I thinned it, but aside from longer curing time, there was no notable bad effect.
 

dougk

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Looks like Spanish Cedar?

I'd wick thinned Titebond in and reclamp. You could spline but I'm not sure its needed at this point.
 

w666

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Thanks. Tempting, but I do think I'll fix it now.

You'll probably need a more fluid glue that can penatrate on the crack before clampig. If the crack is already in touch, maybe dangerous to force a opening and increase the cracking.
Maybe you should just leave this way. If under string tension is not bigger, or loosing tune.
 

w666

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OK, thanks for trying it first :)

I've thinned Titebond I with water and syringed it into a narrow crack. Titebond recommends no more than 5% water for thinning - can't remember what percentage I thinned it, but aside from longer curing time, there was no notable bad effect.
 

w666

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It does look like Spanish Cedar, but Martin claims that it's Mahogany.

Another vote for thinned Titebond.....it's starting to trend that it's the way to go!

Looks like Spanish Cedar?

I'd wick thinned Titebond in and reclamp. You could spline but I'm not sure its needed at this point.
 

J-Dizzle

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I've thinned Titebond I with water and syringed it into a narrow crack. Titebond recommends no more than 5% water for thinning - can't remember what percentage I thinned it, but aside from longer curing time, there was no notable bad effect.
yep my first thought was also to syringe it in there.
 

Dougie

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There is another way to get full viscosity titebond way down into the crack, and that is with compressed air. Make a jig to hold the crack open like it's under string tension. Wax all of the surrounding areas with a thin coat of paste wax like floor wax or bowling alley wax. Do NOT let any of the wax get near the crack. The wax is to keep your cauls and stuff from sticking. Wax the surfaces of any wood/lexan blocks that are to be used against the wood.

With the crack ready to glue, squirt a bit of slightly thinned titebond as far as you can get it into the crack, let it sit about 10 secs, then blow into the crack and blow out most of it with compressed air. Don't blow extremely high pressure into the crack, that could cause shreds of wood to dislodge and become misaligned and the crack won't let you compress it all the way then. Use enough air pressure to clean out the crack and that's all it needs.

Now, with another syringe force full strength titebond into the crack, hold the peghead downward, and gently blow the air so it forces it down as far as it will go, leaving (or re-applying) enough titebond to squeeze out.

Now you can glue it up like a normal repair and clean off the squeeze out, should be good to go in 24 to 48 hrs.
 

w666

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Thanks for all the great ideas! Here's what I did:

1. Gravity - I strapped the guitar to a board and then clamped it in my bench vise so that the guitar was vertical. I used a clamp (very carefully!) to open the crack as wide as I dare.



2. Thinned Titebond and a Syringe - I mixed up a tiny amount of Titebond (from a brand new bottle) and an even tinier amount of water, and then sucked it into the syringe. I inserted the needle as far as possible, and slowly filled the crack, allowing time for gravity to do its thing.



3. Clamp - I slowly clamped up the joint, cleaning up the glue as it seeped out. I used redwood cauls as it was the softest wood I could find laying around. I hope it doesn't leave a mark when I take the clamp off.

 

Brian I

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Nice looking repair. Definitely looks like SC. Martin uses it for most of the 16 series and the D-35 model: my 000-16 has a sc neck and sounds great.
 

w666

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Hmmm....this is indeed a 000-16. Maybe it is Spanish Cedar, then. This one has the Macassar Ebony fingerboard and bridge too!

Nice looking repair. Definitely looks like SC. Martin uses it for most of the 16 series and the D-35 model: my 000-16 has a sc neck and sounds great.
 

gobig2000

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I need to do this exact same repair on a mates SG and was in the middle of working out how to go about it when i stumbled across this! great timing and great job man.
 

w666

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So here's the result....



Lessons learned:

- Gravity is cool!
- Next time I will get some leather for my caul :(
- Adding water (even a tiny amount) to Titebond most definitely retards its cure time. The leftover thinned Titebond I left in the mixing dish was still not cured after overnight in the open air! I think I'll wait another day or two before I put the strings back on.
 

j.six

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Neat!

You MIGHT be able to steam that dent back up with a soldering iron and a damp rag (obviously after the glue is cured). I recall Greg mentioning that you can do that with lacquer finishes.

Sully
 

w666

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Thanks. Don't think I'll risk the steam, however. Besides, the dent adds character :) My primary concern was to arrest the crack before the headstock flew off and hit me in the face.

Neat!

You MIGHT be able to steam that dent back up with a soldering iron and a damp rag (obviously after the glue is cured). I recall Greg mentioning that you can do that with lacquer finishes.

Sully
 

pinefd

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Neat!

You MIGHT be able to steam that dent back up with a soldering iron and a damp rag (obviously after the glue is cured). I recall Greg mentioning that you can do that with lacquer finishes.

Sully
That's correct, Sully, he did say that. I thought that trick would only work on bare wood (and use it quite often), but Greg said that it will work on lacquer finishes as well.


Frank


p.s. Great job on that headstock repair!
 




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