broken neck

Why do Gibson headstocks break?

Why do Gibson headstocks break?

There's a big chunk of my income that comes from repairing broken necks and headstocks. And, by far the biggest chunk of that comes from repairing the broken necks and headstocks of Gibson guitars. 

So what is it that makes Gibsons more prone to lose their heads?

Guitar Headstock Repairs with Rubber Bands

There's a lot you can do with a bit of wire, a luggage ratchet-strap, and a big rubber band. 

In some cases, the best way to repair a guitar headstock doesn't involve clamps and cauls. Depends on the particular damage but this one doesn't need anything more 'specialist'. 

Repairing the headstock crack on this Gibson guitar doesn't call for lots of clamps and cauls

Some breaks are much easier and 'sounder' to repair using straps and some rubber bands.

Now, I should mention that this isn't always suitable. In many cases, it's a terrible idea. However, with the 'right' break, this method is not only easier but gives more secure crack closure while the glue cures. 

UPDATE: 

A comment made me realise I hadn't actually added an 'after' picture. Rectified now. Finished repair below. 

You can just make out the crack below the transition from headstock to neck (although—if I do say so, myself—you have to look pretty closely).

Repairing a Nasty Headstock Break

I’ve written a bit about headstock breaks before. I get to see a lot of them. Probably ninety percent tend to fall into a category I call “Gibson-Style Headstock Breaks” and are usually relatively straightforward to repair.

The other ten percent can prove a bit more challenging, though.

That's a nasty break

This one’s nasty. It’s a ‘short’ break meaning there’s not much glueing surface to provide ‘grip’. It's also got some nasty splintering and, while the owner thought to collect some of the loose splinters, most of these won’t jigsaw back cleanly (and there are some missing).

If ever a headstock repair needed reinforcement, this is it.

Splining is one option for reinforcement but there’s too much damage here to make that a viable option (and, as an aside, the truss-rod has a pretty big ‘anchor’ that leaves little room either side of it).

Nope. We’re going overlay on this one. Again, I’ve written about overlays before (here and here for example).

The wrinkle on this repair is that there’s some serious splintering and I want to be as sure as possible.

Double-overlay, baby!

Overlay on the front and the rear.

Lots of photos follow:

As usual, I have to repair the break first to get the headstock reattached. While this isn’t too much trouble, there’s no way the repair could stand up to string tension without additional reinforcement.

Partial overlay on front of broken headstock (untrimmed)

The front first. I wanted to keep the maker’s logo intact so I removed some wood for the overlay and ‘feathered’ it towards the end of the headstock. The image above shows the inlaid overlay before the edges were trimmed.

Zoomed section shows feathering from new to existing wood

You can (probably) see in the side view photo. There’s a ‘fade’ from the existing wood to the overlay I’ve added. I’ve still extended the overlay well past the break so there’s plenty of good wood for it to grip.

Overlay trimmed and re-drilled for tuners

Above is the trimmed front overlay. The raw wood is the new section and the black headstock end is (obviously) the pre-existing section. I've re-drilled the tuner holes that were covered by the overlay. It's a good idea to do that now. If I'd waited until the back overlay was on, I'd have lost them. ;-)

The backstrap overlay. 

Now around the back. Again, I remove wood from around the repaired section and into the good wood either side. Then a new piece of wood is inlaid into this ‘lower’ section to bring it back to the height of the original wood. These glued-in overlays provide a lot of strength to the repair. 

Because the headstock is angled back, I pre-bend the overlay/backstrap before it's inlaid. Some more info on the backstop bending if you want it. 

The feathered transition from old to new is clearer here

Cleaned up around the front and applied some sealer. This lets you get a better look at the feathered edge of the overlay—the transition between new and existing.

A little lacquer tidies things up

Now we’ve got some colour and lacquer applied. Everything’s nice and tidy and, as you can see, it’s strung-up and holding. Great.

And around the back, it's looking ok too. 

Around the back and the clear finish means we can’t have an invisible repair but it’s pretty discreet.

Not too shabby, I reckon. 

Guitar Neck Repairs: Splines

Headstock repairs are nothing new in these parts. If you pop by the Haze blog from time to time, you'll probably have seen more than a couple over the last few years. We've also talked about the need to reinforce some broken headstocks with a 'backstrap' (a piece of wood that overlays the repair to add strength).

I like backstraps. They're an effective and discreet way to strengthen a neck repair. They can take a bit of time and effort to do properly, though, and splines are not the only game in town. There are times when an alternative is preferred. 

Splines are the prime candidates.

Spline Headstock Reinforcement

A spline is a slat of wood that's inlaid into a channel cut in the neck.

Like this:

Reinforcing a broken guitar neck repair with splines.

The idea is that the channel runs for a distance either side of the repaired crack. A slot is routed and the spline glued in. The newly inserted 'good' wood of the spline ties together the good wood on both sides of the crack.

As you might expect, the splines are carved down to match the neck and the finish touched up. Splines are not quite so inconspicuous as a well-executed overlay but they are an excellent way to bolster a neck repair that needs some reinforcement. 

And, in the right circumstances, you can even get inventive in your splines

 

Weak Neck Fail

repair guitar neck

This is a particularly handsome Heritage 535. It would be even more handsome if it were in one piece instead of two, though. The neck's come off and a little bit of investigation shows that it never stood a chance. This neck joint was weak from the start.

These joints are referred to as 'mortice and tenon' joints. In this case, the tenon (the bit at the end of the neck) was too small for the mortice (the 'pocket' in the body). As well as having a relatively large shim on one side, the tenon didn't make contact with the bottom of the pocket. There's an gap of a couple of millimetres between the two.

You can see the circled bits in the image. On the left is a chunk of mahogany from the tenon that's split off and the glue line is visible on the right. You can see the gap.

That gap means no glue joint there. Only the sides are glued (well, those and the 'face' of the joint but that's not providing a lot of strength).

This is a weak neck joint that was much more prone to fail that it ought to have been.

Rather than just gluing it back together, I'm going to build up the tenon to get this joint to where it should have been from the factory.

guitar neck tenon break
neck joint failure repair

First off, that little chunk of mahogany that's still glued to the side of the neck pocket has to be removed and glued back to the neck tenon. Once that's done, I nab a new bit of mahogany and thickness it so that it will fill the gap.

In the right photo, you can see I've glued this on and cut it to match the shape of the existing tenon. The thickness of the added wood gives you an indication of how much of a gap there was.

fix guitar neck joint
repair guitar tenon joint

I removed the old glue from both parts and re-glued the neck to the body. Because the break was quite clean, only a little touch-up work was required to get the guitar looking its best.

This repair looks good and, importantly, has actually resulted in a better, more sound, neck joint than when it left the factory.

ASAT OUCH

ASAT broken headstock.jpg

Oh, that's not pretty. And it's a shame, as this is a nice guitar. It's a G&L ASAT (as you can see) but it's got a bit of a 'hybrid' vibe going on. Mahogany neck and body and a tun-o-matic bridge with tailpiece gives a Gibsony vibe while the bolt-on neck and slab body bring things back to the G&L/Fendery end of the spectrum. As a man who appreciates some of the advantages getting the best of all worlds, I quite like this guitar.

So let's get it fixed.

You can't really tell from this image but this is actually the second time this guitar has broken in the same place. A second repair is usually more complicated because the residue of the original repair-glue makes it very difficult to ensure a clean joint. Also, this is a reasonably 'short' break—there's not a lot of glueing surface to bear up to string tension.

All of this means that the best chance of long term success with this is to reinforce the repair. A strong and discreet way to handle this reinforcement is a backstrap. We've talked a little about backstraps before—the method involves taking a little wood off the back of the head/neck and overlaying new wood in its place to add strength.

Asat2
Fender-style neck repair

First up, though, we need to get those two pieces back together and that calls for some inventive holding/clamping. This repair necessitates the pieces be mated longitudinally which required some thought. Meet the all-new Haze 3-D Fender-Style Neck Clamping System (patent application pending). This contraption allowed me to keep the neck aligned and rigid while I pressed the two pieces together and while the glue cured.

G&L Neck repair
Fix guitar neck

Once the parts are joined again, I can remove some wood from the back of the headstock, going past the break and into 'good' wood so that the applied backstrap has something solid to grip. We're not taking a lot of wood here—around 2mm in this case.

I then search out a piece of mahogany that's got a reasonably similar grain pattern to the headstock and thickness it to about the same thickness as we removed (in reality, it's generally a hair over to allow for sanding out). Off to the bending iron to work in a slight curve that will match the transition from flat headstock down to the neck.

guitar repair dublin
Instrument neck repair

OK, I know that's not the most attractive clamping arrangement ever but it gets the job done. You can see a curved hunk of ash acting as a caul to clamp the curved area. Once the glue's cured, I tidy up the edges with a magnificent array of routers, rasps, knives and, finally, sandpapers. The overlaid piece is pretty obvious in the photo above right.

G&L ASAT guitar neck repair
Electric guitar neck repair

A bit of work is required to fill the missing chips and chunks from the break. A little lacquer, some spit and polish and we have a guitar that's soundly—and pretty discreetly—repaired. It plays great and it sounds great. This repair should outlast the owner if he can avoid Pete Townsending it into a speaker cabinet or something similar.

Reinforcing A Broken Headstock

SG Broken Peghead Repair

A while back, I outlined a (slightly) unusual method of repairing the broken neck of a Gibson SG. I mentioned that guitar would make another appearance soon and here it is. The guitar suffered a broken headstock while still in its case. A neck-break in the case was the final straw for the owner—who's had more than one Gibson require a neck repair— and he wanted to consider options to help prevent it happening again. We talked over the pros and cons of the various solutions and eventually decided on a backstrap overlay.

This methodis sometimes used where the break is too nasty or offers insufficient glueing surface to guarantee a sound repair. A backstrap was not a necessity to repair this particular break (and, indeed, it entailed additional expense to carry out) but the owner wanted to do something that would go towards preventing a reoccurrence.

Illustration of backstrapoverlay

Illustration of backstrapoverlay

A backstrap overlay involves removing some wood from the rear of the headstock and some way past the broken section. A patch is cut from new wood and is bent to conform to the curve between headstock-angle and neck. Because the inlaid patch has been bent to shape, its grain has no run-out and remains strong.

I explained to the owner, and I will to you, that this offers no guarantees. However, this method of applying bent wood certainly strengthens a weak area of the guitar and it will be stronger than the original.

Backstrap peghead repair
Headstock repair backstrap overlay technique

The first thing that needs to be done is to repair the existing crack. I've discussed this in a previous post so I'm not going into any detail here. A repaired crack is necessary so that the section to accommodate the backstrap can be removed. My usual preference, when doing this, is to run the strap right to the end of the peghead as the inlaid wood is more discrete. In this case, doing so would have removed the serial number and 'Made in USA' stamp and I decided keeping these better served the future value of this guitar.

A 3mm section is removed from the back of the headstock. The Saf-T-Planer allows me to do this cleanly right up to the point the neck angle gets in the way. The remaining section along the neck is removed with hand tools.

Bending wood for broken guitar neck repair
Repair patch for broken headstock

A piece of mahogony is thicknessed to the appropriate size and cut out roughly to shape. Out comes the trusty bending-iron and I work the wood into a gentle bend to conform to the section I've cut in the neck.

Clamping backstrap overlay on broken peghead repair
Reinforcing weak neck on Gibson SG

Some inelegant, but effective, clamping and glueing and the backstrap is in place.

But it's not pretty. The patched in piece does allow you to get a look at the bend clearly though. Because the grain in that patch (backstrap) runs—uninterrupted—from end to end it's much stronger than the piece that was removed.

Neck repair on Gibson SG
Completed SG headstock repair

A little work with routers, drills, knives and sandpaper and the new piece looks a little more like a headstock should. Some touch-up work helps hide the evidence. A (relatively invasive) repair like this can never be completely invisible under a translucent finish but this is pretty discrete.

We've repaired and strengthened a broken-necked SG and preserved the serial number. Not a bad few day's work.

Cross-posted to Guitarless

Broken Necked SG Gets Strapped

Gibson SG broken neck

Gibson SG broken neck

Nobody likes to see this. It's the headstock of a Gibson SG and, as you can see, it's broken. Ouch. Something slightly unusual about this is that this guitar suffered a headstock break while still in its case. This is unusual but not unheard of. I've seen a few in my time (and I mention it in my general article about Broken Necks). It's a real pain to hear this but even a good case might not protect your guitar in all circumstances. If you want to be even more safe, you can slacken off the strings before you pop your guitar in its case. Not the most practical solution but it is what it is.

Anyway, we've looked at headstock breaks before but I wanted to show you some unusual clamping arrangements on this one.

Hide Glue Guitar Headstock Repairs
Compression Strap Clamping for Guitar Repair

First off, let's get the glue pot heating up. I'll often use hot hide glue for repairs. If you use it correctly, it's very strong and creep-resistant. I like the 'traditionalist' vibe of it too. Depending on the repair, it can be particularly suitable too (as it was in this case).

And the next photo—whoa, what's going on here?

We've looked at various clamping methods before and discussed making custom cauls and whatnot. Sometimes though, headstock breaks can be very soundly and securely clamped by the clever application of ratchet compression straps.

"Are you mental?" I hear you cry.

Nope. If the neck crack is held on by the headstock veneer and, if it mates cleanly and securely, it can often be easier to use this method of getting the break back together. The strap is secured at either end—around the strap-button and through the tuner holes and it can apply a strong, directional pull to keep the break together for glueing.

Inventive Clamping for headstock repairs
Ratchet strap clamping for repair

The block of wood I've used at the front of the headstock just protects it. Likewise, the cork padding on the rear of the body. Once the glue has been applied where it's needed, tightening the ratchet applies the pressure that pulls the cracked headstock together again. There's plenty of force—in fact you could probably pull the headstock off completely if you over-tightened.

Let the glue cure and clean up the excess with some hot water and a rag (another great advantage of hide glue) and it's done.

This guitar will be making another appearance soon. Stay tuned.

Incidentally, I didn't invent this clamping method (more's the pity). Years ago, Stewart MacDonald's catalogue used to include occasional tips from guitar techs and luthiers. I read this there and have been thankful for it plenty of times since.

Guitar Repair: Acoustic Neck Break (Reassembly)

Instrument Repair Dublin

A little ways back, I discussed the removal of an acoustic guitar's neck for repair. I also talked a little about my opinions on the construction of that particular guitar. The neck-removal post was getting a little long so I decided to split out the reassembly part. Putting an acoustic guitar back together generally involves some glueing. Sometimes more and sometimes less.

A bolt-on neck will generally just require that the fingerboard extension (the part past where the neck meets the body) be glued to the guitar top while the bolts inside will handle the job of pulling, and securing, the neck into the body.

A dovetail neck joint requires this but also needs glue in the joint itself. Depending on the manufacturer, the face of the heel (the flat portion that butts against the guitar side) may be glued too. Some guitar makers (Martin, for instance) don't apply glue there while others (Gibson for example) glue it. This is one of the reasons it's a bit more work to perform a neck reset on a Gibson.

Fix acoustic guitars-Dublin
20110618 IMG 1212 small1

In the case of this particular guitar though, the heel face is entirely flat and is all a glueing surface. The steel box-section tenons must also be glued into their corresponding mortice (channel) in the top and the fingerboard extension must be fixed to the guitar top.

Complicating matters is the fact that there is no force that would pull the neck into the body in the same way as a dovetail or bolt-on joint would. This means I had to clamp the neck into the body in some fashion while the glue cured.

Some inventive clamping-caul making later…

And I had a wooden caul that would fit the curved heel, letting me clamp the neck into the body. Ready to go. I did a couple of dry-runs with no glue as this was a tricky clamping job. When I was happy I could get the clamps on quickly and accurately, I went for it.

Guitar Neck Repair
Stringed Instrument Repair

That clamp in the photos—running from the soundhole to the heel—wouldn't normally be required but this instrument's construction made it necessary. The clamp doesn't actually contact the soundhole edge but I've got a piece of linoleum there to play it safe.

Once the glue's properly cured, it's ok to unclamp. I replaced the fret I removed (see the previous post) to help steam off the neck, made sure it was secure and level and I strung this little fellow up to make sure it played well.

This job was a little more involved than it might be on a different guitar. All that's not important though. What's important is that this guitar is making music again. That's always good.

Cross-posted to Guitarless

Guitar Repair: Acoustic Neck Break (Neck Removal)

Fix Acoustic Guitar Neck

In a previous post, I gave my opinion on what I saw as the problems with the neck-joint design of a guitar I'd recently worked on. I thought you might be interested in some more detail about that repair (without my whinging about design issues). While some of the steps undertaken in this repair are common with any job that involves removing a guitar's neck, you might find it useful to, first, check out some of the ways in which this guitar differed. The guitar had taken a knock and its neck had become detached at the heel. It still appeared to have some attachment towards the guitar top but it wasn't easy to see what was going on. Internally, there was quite a small neck block—too small to accommodate a dovetail—and no sign of bolts although the feeler gauge I inserted seemed to indicate something bolt like. It actually took a chat with the manufacturer's customer service to sort it out. There were no bolts or dovetails—dowels were used to align the neck and the joint was a mortice and tenon.

Fixing a problem like this on a guitar isn't just a matter of squirting some more glue in and hoping for the best. A proper job requires that the joint be disassembled and cleaned. If this isn't done, the new glue will not penetrate properly and will only adhere to the older, failed glue rather than to good, strong wood.

Acoustic Guitar Neck Repair
Fingerboard Removal in Guitar Repair

Removing an acoustic guitar neck involves softening whatever glue is holding the neck to the body. A dovetail requires holes be drilled into the joint so that the glue can be softened by carefully injecting steam. That's not required for a bolt-on neck, of course, but what is common with all joints—including this one— is that the glue holding the fingerboard extension to the guitar's top be loosened. We do this by applying heat.

Sometimes that heat is applied using a cast block that I heat on a hotplate. For some jobs though, I use heating blankets. These are much more controllable but you still need to take care. The blanket is clamped—loosely—to the fingerboard extension and I keep a very close eye on it. When I judge that heat has penetrated the board and begun to soften the glue I remove the blanket and get to work with the palette knives. It's a delicate job as too much pressure could easily tear into, or lift grain from, the guitar top underneath. It's often necessary to heat the area a couple of times to separate the surfaces.

Once the fingerboard extension is loose, the neck removal can begin. As I mentioned, on a bolt-on this is an simple as undoing some bolts while a dovetail would need the joint steamed loose. On this neck, removal was complicated because of the construction.

Fix Acoustic Guitar Neck
Instrument Repair - Acoustic Neck Repair

You can see from the images that the neck has two steel box-sections protruding from the heel. These were glued into the corresoponding channels in the guitar top. I needed to get this glue to soften too but the heating blanket wasn't going to do the trick. It was necessary to use a similar technique to that used for dovetail disassembly. I removed one of the frets on the extension, drilled a couple of small access holes and injected steam (very carefully—these are small channels very close to the guitar top).

This process, too, was made more difficult than on a traditional construction. Because of the alignment pins, I could not remove the neck from the body vertically. Instead, I needed to 'pull' the neck away from the side. It made for an annoying job as it's really hard to get any leverage or apply pressure well.

—o—

As this is becoming a little long, I'll cover reassembly in a future post. Oh, the suspense…

Cross-posted to Guitarless