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Looking to make a headstock repair routing jig, to add reinforcement to a "typical" broken off/cracked headstock.
Anyone got pictures of their own one?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I can't help you with a jig, but I will caution that adding splines is often unnecessary and sets the guitar up to be vulnerable at the end of the spline where you have endgrain to endgrain.

Where really necessary if there is insufficient gluing area etc a backstrap is generally better

I haven't done a repair with splines, Colin, but I've done three like this. This guitar I bought with the head missing, and two with Gibson breaks. I think I have some jig pics on an old laptop.



Alex


Sent from my iPad using Tapatalk

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"Indecision is the key to flexibility" .... Bumper sticker

What Jeff said. We have very rarely, likely not for the past three years or so had to add a spline to a headstock break.

The beauty of a well designed headstock jig and careful prep work matching fibers for an excellent fit is the jig will provide sufficient clamping on all axis making the repair as strong or stronger than before the beak or crack happened.

Our jig and others that are also well designed have been posted on the OLF before if you want some pics. We likely repair one a week and have never had one open back up and come back.

Found it, a YouTube that Dave did about six years ago. This jig has been copied that we know of dozens of times (people often ask us for permission and guidance).

It works very well and we get big bucks for these repairs. As mentioned most of the time, likely over 99% of the time no spline is needed.

Can you post the link, Hesh?

Seems like there are three parts of headstock repairs

- aligning, clamping and which glue to use on the initial break
- whether to spline, back strap or both or neither
- dealing with the finish, especially "modern" finishes, stains or colors.

I'm doing a repair on a 12 string that has all of these - I added a carbon fiber graft and a back strap and I'm dealing with the finish right now. I was going to post it at the repair subforum when it was done.

However I really would like to see some sort of universal jig that holds everything in alignment during the initial glue up

Sure, meant to before but forgot.... https://www.youtube.com/watch?v=D6lzTM__Yrs

Another part to doing headstock repairs is to know when to decline.... Rarely will we decline but if some hack squirted liquid nails or some other unsuitable glue in there we won't touch it.

We use splines to repair perhaps a dozen or so instruments a year, and as Mr. Breakstone suggested, only those that are not better repaired by other methods or converted to wall hangings in themed restaurants. The usual suspects are those instruments with 2 or 3 unsuccessful repairs already made by others, missing or glue-contaminated wood that precludes more conventional repairs, enough intact structure that the splines will have something to hold on to when placed, and stock orientation beyond the limits of the spline that will not simply create two additional failure points at the ends of the splines.

As Mr. Breakstone again suggested, most of the candidates that will show up in repair shops will likely be rejected out of hand, but there are enough that come through this shop worth saving that the boss built the pictured fixture to hold instrument and 2D mill.





Fitting the splines:



Other issues:

- There is need for precision in placing the splines to avoid interference with the truss rod or risking damage to the peg head veneer

- Milling a set of stepped depth, non-parallel slots with a conventional router is very difficult; although some sort of guide can be used, we found that the same sort of 2D mill that Frank Ford suggests (see his linked Bridge Mill article) works well for the job, or other 2D/3D/4D mills would likely work just as well.

- I still do not have a good understanding of when and when not to spline, beyond what I've already mentioned. Having a fixture and mill to perform the hard part of the repair - the milling - is beneficial, but having the experience and knowledge to know when splineing is a forlorn hope or will exacerbate the instrument's issues is essential. The ability to perform the repair does not confer the knowledge to know when it's the right course of action.

- With touch-up, these are 3 to 5 hour repairs, or about $300 to $500 of labor. The use of the fixture cuts out at most an hour of work, versus creating one-off temporary fixtures for cutting the slot, but this is still an expensive repair that needs enough retained value and chance of success that most guitars in need of neck repair will not be candidates.

Mr. Ford's bridge mill article:

http://www.frets.com/FretsPages/Luthier ... ill01.html

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A constellation only takes shape when one maps the whole.
- Beth Brower

Many thanks Woodie, and Hesh/David

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Now those are decent splines, Woodie.
Most that I see are significantly less than half that length, and definitely not with a stepped base.

My little jig is the antithesis of David's and Woodie's but it seems to work and it was dead simple to build. Its a piece of 1/2 ply wood 3 inches wide and 24 long. I mounted another piece 3-1/2 wide at an angle of 16 degrees at one end. 3-1/2 inches is about the widest headstock I've seen and most of them seem to be around 15 or 16 degrees - I can shim if the angle isn't right.



The fact that the plate stands proud allows for the height of the fretboard and frets above the headplate. I mounted the angle in the center - that lets me get clamps all around it. It is 9 inches long which should allow me to do 12 strings. Here it is from the back



For most breaks I simply clamp the neck to the base and my work bench (supporting the guitar with a towel or something). I cut a couple of pieces of wood to act as end stops and made a couple of cauls for the back side in different shapes. This Martin neck has a dart so I cut a little recess for it



I can get about 3 clamps on each side of a normal headstock, one across where it curves to the neck and the little end stop.



A shot from the back showing how the clamps clear the base and are perpendicular to the head stock



Works fine for most breaks altho you have to fiddle around a lot getting everything ready before gluing. With a simple break I'm able to work fast enough to use hide glue. For a complex break I usually use Titebond.

Some refinements - I need to put some cork on the surface where the frets rest. I'd like to build a little pushing clamp for the end - a piece of angle iron with 2 threaded holes and a couple of bolts pushing against the end of the headstock (see Hesh's video). It would be totally cool to have the angle adjustable - I doubt that I'll ever do that. Making both the base and head part wider would allow toggle clamps to be used - not sure how much advantage that would be.

Anyway, a couple hours of work, some scrap plywood and it seems to work fine for a part time hobby repair person.

I'll also show a recent repair. This was the second go around on a 12 string - the first repair failed, it was not completely open but I got it cleaned up and glues fairly well. I thought a back strap was called for so I took 0.080 off the back with a Safe-T-Planer



This is a Guild 12 string with two truss rods - they end right where the break is. Rather than doing true splines I simply chiseled a little recess and glued in some 0.030 carbon fiber across the break



I bent a piece of 0.080 mahogany side material and fitted it across the break and CF.



Am currently dealing with the finish - stained the new wood to match the neck, put on one coat of shellac and then nitro feathered into the original poly finish. I think its going to be OK but I haven't done the final buffing yet.