Third (or more) time the headstock of a Les Paul broke - soliciting advice

[eliya]

I have a friend's Les Paul whose headstock broke for at least the third time. I did not do the previous repairs, but I'm going to do the next, and hopefully last, one.

This last time the headstock snapped was out of nowhere. My friend played the guitar for a few practices and maybe a show, and everything was fine. Then one day he went to grab it (it was sitting in a stand) and discovered the the headstock had snapped. The guitar didn't fall or get bumped, but it was under string tension. It also happened when the weather started getting warmer in the spring, so that could be part of the reason why.

I have a few headstock repairs under my belt, but none where someone's been there three times before me. As you can see from the pictures, the breaks all happened in the same area, and my fear is that the joint, which is already weakened by design, will be even weaker now. So I'm hesitant to just go in there with glue and clamp it up. I'm thinking of reinforcing it, but I don't have a solid plan as to how.

Any advice and insight you guys have will be grand!

[Ned Knepp]

Hi Eliya, Long time no read.

 It looks like it needed a backstrap repair from the first. There is a thread, here, that is only a page long but has two links and some great pictures posted by Rusty covering backstrap repairs. One of the links goes to Frank's page on Frets.com and the other goes to another site. Don't overlook Rusty's pictures. They are worth adding to any reference material you may be saving.     

Do you know what kind of glue was used before? It doesn't look like any of the standard "carpenter" glues.

[eliya]

Thanks, Ned! This is exactly what I was looking for. Now to figure out if I want to take on this job or not.

I believe there's some carpenter's/wood glue and some super glue in there. Not 100% certain, though.

[Howard Klepper]

Is that a Gibson?

At this point, if I wanted to warranty my work, I'd give it a new headstock scarfed into the neck.  All the backstrapping in the world isn't going to fix the broken end grain in the front half of the headstock.

Don't use ordinary Titebond--not enough heat resistance.  Fresh hot hide glue, or use Titebond Extend.  The latter should be better known.  It dries a lot harder than regular Original, and importantly for this application, it gets about 40 degrees F. more heat resistance.

[eliya]

Yes. It's a Gibson. Scarfing a new headstock is another idea I thought of, and if indeed that's what's needed, it'll be someone else who does it.

[Russell Vance]

A deep laminated backstrap repair (removing the endgrain break area) will be fine. We've done many of these and have documented and imaged the repair genus previously (thanks to  Ned for the reference), including the inclusion of concealed graphite fiber cleats to further bullet proof the repair. We give a three year warranty with these repairs but haven't had one back over the 10 years we have been doing this common repair.   Titebond or Titebond 50/Extend (same overall strength/shear performance through all three, give or take a few pounds either way) is fine.  

This is not an entry level repair and any gaps in your knowledge or ability will result in gaps in the repair, if you get my drift.

Note: I have recently repaired a second break LP CS headstock (once off a stand, once against a door jam) and noted that the mahogany was so soft and light that a push with my finger nail would actually cut the fibers - in this case I refused a warranty as the choice of wood for the neck was not, in my experience, acceptable.

Talk through this if you wish Eliya and expect a twelve hour delay due work and time constraints, it's doable but you need to follow the procedure closely and have the proper resources available.

Regards, Rusty.

[Howard Klepper]

Rusty, you could laminate backstraps all the way up to the headstock face to eliminate the endgrain break.  And then it may need a new face veneer, too (no photos of that).  That would from my perspective go beyond a backstrap repair to replacing the headstock-- but with a laminated one. Why do that rather than replace the headstock with one piece (reusing the old face veneer if it is useable; making a new one if not)?  Is the point to end up with a laminated headstock (stronger than solid, but more at variance with the original construction)?  The solid piece would also be stronger than original construction, with the grain  running with the headstock, instead of through it.

[Russell Vance]

Hi Howard,

I steer clear of scarfing necks unless the damage is catastrophic mainly because laminating a back-strap is as strong as the original section removed and often much quicker and easier than making a new peghead and sorting out the truss rod cavity and bearing surface and doing the re- serial number gig etc.

Obviously, the removal of the original serial number stamp and branding and the inclusion of a scarf joint leaves the guitar open to suspicion as to authenticity when it is up for resale.

But, back to the nuts and bolts:  if the guitar is finished black or shaded all the easier with no tell-tale obvious scarf line imprinting in the lacquer over time.   Re-fibering a top happens every so often  but is no big thing and a constant in both styles of repairs if the front plate is severed

I put that a scarf joint on a LP is more at variance to the original design than a conformal backstrap repair.

However, either repair works, and done well works beyond what is needed, what I have put is our repair perspective and fundamental and peripheral reasons for doing what we do.  

Rusty. 

[eliya]

Thank you, Rusty! I believe this is a repair I can do - the hardest part is figuring out how to remove material from the back of the peg head. I'm thinking the safest way might be to take a rasp to it, like you mentioned in the other thread.

A couple of questions:
Howard believes that it'll be necessary to remove material from the headstock all the way to the face veneer. Is that something you recommend? None of the backstrap repair pictures I saw showed that the material is shaved all the way down to the front of the headstock.

Ballpark of how much material to remove? Seems like 1/8" is the consensus.

Howard, the overlay is pretty messed up, but my friend isn't too concerned about it. I'm attaching a picture of it.

[Russell Vance]

Hi,

Glue everything back together with Titebond or epoxy after exposing as much fresh wood as possible with cleaning out the old glue.  Use a flat hard caul protected with brown shiny packing tape to get and keep the peg head face flat and square and clamp it up with hard cork type cauls on the break side. 

Lean on the clamps and forget what the woodies say about starved glue joints - they are not going to happen here, leave for 24 hours and then flood the area with thin super glue toi take care of the hairline and embedded fractures.   A good brand like Hot stuff or the Stewmac cynacrylate should ensure your fingers are inoperable for a couple of hours while going everywhere (protect and think about where you don't want this stuff to run - gravity to the power of 10 applies to thin superglue).

Machine or rasp out a nice flat scoop as deep as needed to take out the endgrain fracture area and blend into the neck and peghead.  I usually take it up to the E tuner bores so the join is not as apparent when the tuner backs cover most of it.  If you are stripping the back of the peghead do not agressively  sand it, either use heat or stripper and scrub out the serial number indents with a toothbrush dipped in thinners to get a nice indent for the refinish - nothing screams amatuer as a stuffed up serial number.

You may wish to put some cleats in before you put in the backstrap laminate (if you do say so and I  post some options for this procedure).  Use a couple or three veneer style laminates to build up the backstrap, one at a time and flatten them a bit between layers after they have glued - once again clam the daylights out of these so they really mesh into the preceding layer and that way you have a machanical bond as well as a glue bond which goes to both strength and creep resistance.

OK gotta run, have a look at this and ask away while I get to the other stuff later,

Rusty.

[eliya]

Hey Rusty, thanks! I decided to pass on this repair since it'll be my first backstrap, and this is an otherwise nice guitar. I didn't think it's right for it to be the one I try this repair on for the first time.

However, for the sake of my understanding, when you say "Machine or rasp out a nice flat scoop as deep as needed to take out the endgrain fracture area and blend into the neck and peghead." In this case would that be cutting wood all the way to the overlay? Or just deep enough so that the crack will have no chance of reopening?

[Russell Vance]

This sort of thing Eliya - only need to cover the major damage and provide a structural reinforcement.

[eliya]

Thanks. I'm hoping to find a cheap guitar with a broken headstock to try out this repair. Thanks again for all your help!