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-   -   Poll on Headstock Break materials and fixes (https://www.acousticguitarforum.com/forums/showthread.php?t=455551)

funkymonk#9 01-08-2017 02:29 PM

Poll on Headstock Break materials and fixes
 
I have looked a most posts and as usual I seek clarification, my own demon.

With a headstock repair, I think there is reglue with or without spines and backstrap overlay.

If it's a short break, say 1-2 inches in width just below Low E tuning machine.
With or without splines? hide glue, titebond, super glue medium/thick, epoxy?

Long break: same considerations?

Sperry 01-08-2017 02:47 PM

This early 1990s Hohner cost me $10. I removed the tuners, clamped the headstock to my table, and let gravity upon the guitar body open up the crack. A screwdriver assisted slightly. Plenty of Titebond and a business card. The card , covered with glue, went into the crack over halfway, in and out repeatedly, the entire width of the crack. In and out until I was confident of total coverage.

Then I removed the screwdriver and clamp, wiped up some glue, and clamped the headstock proper. Cleaned up all the excess glue. 24 hour set, a little 0000 wool, then a little buffing compound. I'd bet the repair is stronger than the surrounding wood.

The guitar made a good Christmas present, the crack is barely noticeable, and it is easy to play for the novice student who received it.

https://nakedluthier.files.wordpress...tock-break.jpg

mirwa 01-08-2017 05:44 PM

Quote:

Originally Posted by funkymonk#9 (Post 5185940)
If it's a short break, say 1-2 inches in width just below Low E tuning machine.
With or without splines? hide glue, titebond, super glue medium/thick, epoxy?

Length of crack has very little to do in regards to deciding if it should be splined or not, it's more to do with how the grain has been broken.

Steve

Splines

http://www.mirwa.com.au/HTS_Headstock_Spline.html

No splines

http://www.mirwa.com.au/HTS_Headstock_Reglue.html

funkymonk#9 01-08-2017 07:36 PM

Quote:

Originally Posted by mirwa (Post 5186165)
Length of crack has very little to do in regards to deciding if it should be splined or not, it's more to do with how the grain has been broken.

Steve

Splines

http://www.mirwa.com.au/HTS_Headstock_Spline.html

No splines

http://www.mirwa.com.au/HTS_Headstock_Reglue.html

Very nice and detailed, makes sense. On the "no splines" I guess I get confused because I can see on the back it is broken along the grain but on the face it looks like it is broken across the grain.
So then a "longitudinal break" would be along the grain. And what I called a short break meaning more or less straight through the wood, would be across the grain and needing splines.
I like your repair pages.

mirwa 01-08-2017 07:48 PM

Yes, any short crack typically under an inch has exposed end grain, you cannot reglue end grain.

You can add glue to hide end grain breaks, but no strength exists in that repair area.

Strength is achieved by gluing long grain back together

Small end grain cracks for example on the face of the headstock are really irrelevant as there is no strength actually required in this area, its decorative more than anything else.

Steve

B. Howard 01-09-2017 07:25 AM

Splines are not always a good thing.... they can actually weaken the neck after the repair like this extreme case where the first guy put in splines and made the neck actually weaker and it broke two more times...eventually shattering.
http://howardguitars.blogspot.com/20...ck-repair.html

mirwa 01-09-2017 07:34 AM

I would agree somewhat Brian.

I think if it's possible to repair a surface without splines then definetly that is the path to go.

Backplates are also options, I actually have a Martin 12 string that came in this morning that I'm doing a backplate repair on.

I also think any spline fitted should not use an end grain join, there is no strength imparted at the ends and this is where I totally agree with you, they can weaken a join to the point of guaranteed failure

P.S, i perused your repairs, the finish work on this one is impressive - http://howardguitars.blogspot.com.au...ck-repair.html

Steve

redir 01-09-2017 07:43 AM

I agree splines are the exception rather than the rule. If it's a simple break then keep it simple. I've done well over one hundred of these kinds of repairs and not once have I ever seen one fail. It's a actually a simple fix.

I have in the past used CA. In fact I was just looking yesterday at one of my own guitars that I repaired with CA about 20 years ago still gong strong. CA has it's problems though, in particular with application and clean up, so it's not really a good choice imho. Titebond is an excellent choice for these repairs and it can even be diluted up to 10% so you can get it deep inside tight cracks.

Epoxy is only necessary when there is severe damage as in the pictures B. Howard showed where there are splinters everywhere and you are going to really need to fill in areas.

If it's like the picture that Sperry posted then just use Titebond ;)

hat 01-09-2017 07:58 AM

I'm not a fan of either yellow glue or epoxy for this. Both can creep. I use Resorcinal glue. Permanant glue. much stronger than Titebond or epoxy. It's the stuff they use to laminate outdoor plywood and airplane wooden propellers with.

Hot Vibrato 01-09-2017 09:01 AM

I've always suspected that splines can weaken the structural integrity of the headstock, making it vulnerable to future breakage. However, some short breaks need splines to hold the repair together. Titebond works great for this type of repair. I suppose I've done hundreds of headstock repairs and I've never had one come back broken in the same place. Epoxy is appropriate only if the break has been contaminated with glue from previous repair attempts.


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