This instructable will show you how to repair a broken guitar neck and, depending on how severe the damage, how to do some minor cosmetic repair. The guitar in question for this example is an Epiphone Les Paul Studio. I actually bought this guitar about a year ago for the very purpose of practicing neck repair - as it already had a broken neck. I fixed the neck about 9 months ago (and you can see the results of that fix in this series).
Fast forward to the arrival of a new puppy... long story short, another broken neck (the old fix held up though!!!) and a chance to create a new instructable.
In the case of the Epiphone, they are great, affordable guitars... And with these broken neck ones (depending on the nature of the break), these can be a great deal for someone with the time and tools to fix them. And if you happen to bust the top off your Gibson ES335, that can be fixed too!
Step 1: Anatomy of a broken neck
Step 2: Tools and supplies
1. Clamps - I like the clamp type shown. I think screw clamps encourage people to really crank it down and damage the finish. You don't need it THAT tight. Several clamps of different sizes works well - I bought an entire set of these cheap clamps at a $5 table at Harbor Freight or Ace or where ever.
2. Glue - No magic glue. White glue is stronger than the wood. I use the "wood" white glue because it seems to not run all over like the regular white type. Plus the curing time works for my purposes.
3. Water - for cleanup
4. Paper towels - Lot's O Lot's.
5. Little artist paint brush - you could use a large brush if you wanted. Size doesn't matter much here.
6. Something to hold the neck up - I have a little tripod thing that I won at a recent demonstration thing. A full roll of paper towels works very well also.
Step 3: Inspection of damage
What interesting to note is that the previous fix held up just fine. The wood failed (again), not the old glue joint. But what that also tells me is that the wood on this neck is fairly weak and would split just as fast and clean if it gets dropped again.
The split paint and paint/wood interface might present a challenge depending on the guitar. But it this case, it did just fine with wood glue.
Step 4: Side note about wood strength and stain penatration.
The wood next to the truss rod opening broke on a slightly different plane. Perhaps is was stronger? Assuming that the break happened how I described in step 1, the truss rod area would have split first... Not so strong after all! So micro-examining the wood structure is probably not worth worrying about for this.
Step 5: Dry fitting
This is pretty simple. Just hold the pieces together and see how they will fit. This guitar was pretty straight forward - just hold it together and you're there. On other guitars you might need to insert part at an angle, jiggle it around a little or clean up some nasty spots on the wood.
I just used one clamp to see how the fit was.
Step 6: Glue application
The goal is to get enough glue that everything inside is coated within the repair - but not so much that it's a total mess to clean up the outside.
Step 7: Assembly and clamping and cleanup
The major parts are:
1. Hand assembly
2. Initial clamping
3. Clean up
4. Additional/final clamping
5. More clean up.
Step 8: Take off the clamps and minor clean up
Theoretically, you could string up the guitar and start playing if you wanted! The joint is solid and will hold the tension. Everything after this is just cosmetic.
Step 9: Wood finish work.
For this repair, I just use a little crayon type scratch filler and buff it down. My goal is to make the repair smooth to the touch... not invisible to the eye.
For a point of reference, I tried to do the finish repair on the previous fix. That's why there's a band of light finish across the neck. It took me about a week to do and it ended up being very noticeable. To be fair, the previous break was missing some edge pieces when I bought it.
Step 10: Headstock cleainup/finishing
1. Clean up the glue.
2. I tried to get it cleaned up and leveled with wet/dry sandpaper. Started with 320 then 400, 600 and 800. Keep it wet and avoid the logo.
3. Black Kiwi shoe polish. I hit the entire headstock with the shoe polish to give it the same gleam. That was the first time I tried that - seemed to work good here!
Note about flash photography: For the majority of my pics, I used a flash. In virtually all of those pictures, the crack looks much worse that it does in real life. From a distance the fix is just not that noticeable.
Step 11: Restring, check set-up and play!
After such a traumatic injury and repair, I was amazed that the guitar held it's intonation!
The only adjustment I needed to do was a quarter turn of the truss rod to get the neck curvature where I wanted it!
I restrung with Ernie Ball Regular Slinkies (10-46) to normal tuning.
Step 12: Conclusion - It's Alive!
This is one of those "OMG what'll I do!" accidents for most people. But if it looks like a clean break and can be pressed back together without to much work, you can probably fix it yourself.
Just don't get to worried about the final wood finish. Keep it simple and you'll be happier than if you try to make the crack totally invisible.
To let you hear the results, I added two sound clips - both were recorded through a Tech 21 Trademark 10 using the effects send straight into the PC. So it's basically a Sans Amp direct.
The first is with a "metalica" type configuration on the bridge pickup. At the end of that one, I let the final open E ring out to give you an idea how well the sustain help up after the fix. Since it's direct with no-speaker to feedback on, it's probably a fair demonstration.
The second is a basic Fender Blackface sound with the neck p'up.
Feel free to ask any questions or submit suggestions.





























































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Anyone have any experience on doing this with a 12 string?
The way I see it is if your guitar has suffered so serious an injury that a glass fill repair is the only thing keeping it from the garbage can, you will just have to live with the fact that the repair is visible.
If you make a good clamping fixture that perfectly aligns the two pieces on the same plane, it shouldn't matter much that some voids had to be filled with glass. You can't just leave the voids. If not filled, they could possibly resonated and weaken the bond. Voids are the second most evil thing (after dirtty or oily mating surfaces) that a joint can suffer.
If your neck looks like a drunk beaver gnawed it off, you are gonna face a little unsightlyness, but you WILL play again.
T-Pig
N. Cal
how do you prepare that "glass" fill ?? you mean fiberglass right ? is that difficult to work with ?
Yes, when I say 'glass' I am talking about chopped (not weave) fiberglass in polyester resin.
Is it tuff to work with? It's a lot more hassle than working with wood, so I only use it in especially drastic situations. I'll give you an example.
A good customer of mine was in a metal band that saw a lot of action. He estimates he's played 700-800 shows from 1991 to 1995. His favorite guitar was a 68 Les Paul that was already beat stoopid when he got it. This is how we met. He had snapped the headstock off several times and had it repaired different ways by different shops, none of which stood up to his abuse for very long. He came to my shop and asked if I could reset the headstock for once and for all.
This was a super tuff job because not only would I have to reattatch the headstock, but I also had to remove all traces of the previous repairs, one of which was two pieces of 1/8" x 1/2" x 3" carbon fiber epoxied onto verticle slots about 1/2" apart from one another. All traces of any glue or fillers had to go as well.
This left serious voids that had to be dealt with. For a normal guitar, I'd carefully match and cut pieces from new wood and glue them in and pay great attention to matching the finish as best as could be, but this guitar lives the life of a crash test dummy so unless I wanted to redo this job for free once a year forever, I needed to forget about trying to bring it back to original condition, and set the headstock in a way that will survive like a cockroach, even if it don't exactly look original. Glass fit that criteria perfectly because the rest of this guitar looked like crap (it had more stickers in it than any guitar I haveever seen, most of which were pictures of nekkid fat women), so the visual aspect of the repair wasn't going to be a factor. All that mattered is that it be the last time it would ever need to be fixed.
I explained to the guy that if he could forgo the finish matching, I could make a structurally sound bond that I could guarantee would not fail anything less than getting run over by a truck. That's what what he was hoping to hear, and that's what he got. Eighteen years later, it's still good.
To anyone who may want to try this kind of fix, I would highly suggest that you take extreme care to make sure the alignment of your clamping fixture is perfect and that it is perfrctly clean...because two things in this world you DO NOT want are #1- seeing your parents get it on and #2- having to remove the glass and resin to do it over again if you make a mistake.
T-Pig
N. Cal
It seems pretty clear that conventional wood glues require a very close fit to make them work but epoxy requires a gap between the wood surfaces to ensure a strong fit.
As an example, wooden strips laid side by side to make a hull cannot be clamped too tightly because the epoxy will squeeze out resulting in a weaker joint.
I hope this helps a bit.
My immediate problem is that I need to repair, as a favour, a lengthwise split in the headstock of my brothers semi accoustic guitar. It is the classic type with 2 slots, with three tuning pegs each side. Basically I need to fabricate one of these slots and I am scratching my head as to how to achieve a repair strong enough to take the strain.
Another watch out with the "messy" break - you may have more difficulty getting the ends to "nest" into each other. You might have to remove some of the troublesome splinters to get a good nesting.
Good luck - let us know how it goes!
#1- I could repair it to a state of full functionality but it would be obvious that it had suffered an injury.....for about $150.
#2- I could do a perfect rebuild of the tennon block, which would involve creating a custom alignment fixture laquer tint matching, etc .....for about $500 and six weeks.
He thought I was gouging him at first, but he opted for the quality fix. Turned out perfectly. He was happy as could be.
Then three weeks later he returned to my shop with a V case in his hand and a bad look on his face. I immediately thought the repair didn't hold and I was prepared to redo it at no charge.
Turned out that my neck heel rebuild held up beautifly....but now the headstock was busted all the way off, in the usual area just behind the nut.
His V was on a guitar stand near his fireplace and his wife was vacuuming the carpet and hadn't realized she got her cord behind the guitar stand and she pulled it over frontwards, right on to it's face.
This time the guy couldn't care less how much I would charge. He wanted the highest quality repair possible. He even considered sending it back to Gibson Custom Shop, but since he was happy with the heel end repair I did, he'd give me the job if I wanted it.
Of course I always did due dilligence on every customer repair I ever did, but I took this unlucky 58 Historic all personal and nursed it back to perfect health. I admit, anyone familiar with that kind of crack can see where it was, but to most people, it looked more like a child's hair suspended between coats of laquer than a Frankenstein's Necktie.
The guy was thrilled, he happily forked out almost $500 (even at that price I bet I still lost money on that job, but it was worth it. That job really boosted my reputation and because of it, I eventally did at least twenty similar very high quality headsplints on extremely valuable guitars over the next few years, in which my efforts were rewarded very nicely)
Once I dialed in my idea of using a machinist's cross slide vise under a 4-flute spiral bit in the drill press (think po' manz milling machine) to precisley control the crtitical geometry necessary to build exactly perfect alingment jigs and clamping fixtures, devistating decapitation jobs started comming out of the woodwork.
Sorry, I still get all misty thinkin of back in the day. My point is that hide glue is for people who plan to eventually remove the part in the future. Epoxies are for people who expect the part to function in extreme conditions and don't mind the ever-present black glue line they leave. If you wanna glue wood together for a guitar, use the exact glue that Gibson uses in the first place, which is Franklin Titebond 40 aliphatic resin glue (aka carpenter's glue or yellow glue) If you prepare the joint properly and you take care to avoid contamination, the bond will hold, I promise.
And by the way, the common mahogany neck cracks behind the nut are not a design flaw. Guitars aren't designed for military duty. If you like being able to adjust your truss rod, then the d-shaped cutout under the truss rod cover has to be the size it is. Be nice to your guitars kids.
T-Pig
When I've gone and repaired hand-me-down furniture (that's very old), it's the hide glue that failed first. If the item isn't worth anything and you just want it to hold up forever, then I fix it with wood glue.
i have had plenty of these break and as a matter of fact it is a design failure on Gibson part as they will all break in the same spot given half a chance.
I don't know that I would go as far as to call them a cheap knockoff. Epi's are fine guitars. This is just a design flaw (or "feature" depending how you look at it) that they appear to share with their more expensive Gibson brothers.