break

Acoustic String Stash

Doing this job, you find some odd things inside acoustic guitars from time to time. 

The occasional string ball-end isn't terribly odd, though. 

However, I'll admit that this many is a little unusual. 

This equals a lot of broken strings on this acoustic guitar

In an ideal world, inside you acoustic guitar should be relatively detritus-free.  

Is this a problem?

Well, maybe not. I didn't get to deal with the owner of this particular guitar in person and I don't know if he/she was snipping the string ends and just letting them fall in or whether strings were breaking and the ends disappearing inside the guitar. There are some heavier strings in the horde so it may be the former but, if your guitar is consistently breaking strings, there may be some things we can do to address that. 

As to whether it's an issue if you've got a hundred string-ends in your guitar, some of that depends on you and whether you find it annoying to have your guitar rattle like a rainstick every time you move—it'd drive me insane but it's your guitar. 

More seriously, though, some acoustic pickups—like those in Taylor's Expression System have magnets. I've had a customer complain his Taylor was making weird microphonic crackling noises—turned out a ball-end had attached itself to the body sensor magnet and its tiny movements were making awful noises (see below). 

So, to sum up, maybe clean out the string ends now and then. Also, maybe the gum, half-eaten lollypops, dead spiders, pencil-sharpeners, and condoms—all of which I've found inside acoustic guitars. The condom was (thankfully) unused. I wish I could say the same for the gum. 

 


Microphonic Taylor Guitar

Update: Within days of publishing this post, the microphonic Taylor thing happened again with another customer. This time I took a photo (albeit a little blurry). You can see the string-end clinging to the body sensor.

The body sensor has a magnet and coil element—like a regular pickup—and this magnet can attract stray string ends. The string can move about and it'll cause terrible squeals/screeches/rustling/crackling/general-unpleasantness. 

Keep 'em clean, folks. 

String ends left inside an acoustic guitar can become magnetically attached to some pickups like this Taylor body sensor

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

 

Repair To Damaged Fingerboard

Rather invasive repair for cracked heel

This venerable old girl suffered a cracked heel at some stage in the distant past. As you can see, the repair wasn't the least invasive solution that could have been imagined at the time. 

These big-ass screws have kept it (sort of) together but the instrument deserves better. I'm not going into detail on the heel repair here—take my word that it's all glued up and sound. Instead I want to look at how we can minimise the damage those screws have caused.

Damaged guitar fingerboard repair

Damaged guitar fingerboard repair

With the screws removed, things don't look too pretty, do they? Incidentally, the two small holes in the fret slot are mine—I drilled them when trying to steam out the neck to repair the heel and they'll be plugged and covered by a fret. The medium hole is a loose pearl inlay dot that'll be replaced later. 

The holes we're worried about are those big, jagged ones.

Of course, we could squidge a pile of coloured filler into them and smooth off the top but that's not going to be the nicest looking repair. We could cut some plugs and glue them into the hole. If we get a reasonable grain match, that'd be a better option but still not the neatest. 

What we're going to do is to replace the entire section of fingerboard between these two fret slots. Effectively, we're going to remove the rectangular section with the damage and *inlay* new wood. 

A bit of digging around my rosewood stock (and scrap pile) turns up a piece with a similar colour and a pretty close grain match.

Inlay good wood to repair damage to guitar fingerboard

Splendid.

If you look closely in the photo, you can see that I've actually routed out the damaged part but left a tiny sliver along the sides of each side. That sliver will keep a nice contiguous look along the edge of the fingerboard and save messing about trying to match the aged lacquer.

As luck would have it, this instrument needed a refret too. It'd be much more difficult to accomplish this well without refretting.

You can see the new fingerboard wood in the photo below. It's a good match for colour and grain and, once it's all clean and oiled, it looks pretty damn good. Stung up, you'd be pretty hard-pressed to notice anything. 

Much better than filler.

Guitar fingerboard repair

Headstock Repairs - More on Reinforcement

So we've looked at a neck repair with an overlay for reinforcement. Let's have a look at the other main method of reinforcing a broken headstock: Splines. In guitar repair circles, splines are long (relatively speaking) narrow pieces of wood that are glued into corresponding channels to provide additional strength.

Failed, previous repair

Nasty glue residue on failed repair

The first repair is the important one.  

Remember these wise words. If the first one fails, it usually complicates any subsequent repair. This guitar arrived in the workshop with its headstock flapping about, held on by only some gummy bits of glue. There was a LOT of residue to clean up. Too much, really. Any glue I apply to repair this break needs to make a good contact with the wood. New glue, trying to grip a film of old glue is a recipe for a poor repair.

Even after cleaning up much of the earlier stuff, I felt some reinforcement was necessary to ensure a sound and lasting repair.  

Determining the truss-rod location with a magnet

Glueing up the peghead before splines

As it happens, the diamond-style volute on this instrument provided me with the perfect idea for reinforcing things. I can rout a channel through that and carve the spline to the same diamond shape. Nice and discreet. Splendid.

First up, I have to keep the truss-rod in mind. I don't want to accidentally rout into a hunk of metal. The magnet on the back of the neck tells me where the rod ends. I note that and get on with getting things back in one piece.  

Diamond volute to be 'splined'

Inset, rough-cut spline

You can see the diamond volute pretty clearly above. I'm not going to take the whole diamond—I'll effectively rout a channel through it and farther along the neck (past the break). 

It's an easy job to shape a piece of mahogany (the spline) to fit this channel. Then a little carving will replicate the original shape. Clean up, slap on a bit of lacquer and we should be able to avoid any more strings of gummy glue.

Spline reinforcement on guitar neck break

Les Paul Neck Removal and Repair

les paul broken neck heel

Yikes. If you've been reading my stuff for a while, you've probably spotted a few different examples of neck breaks. Most of these have been up at the headstock end as that's the more likely place for a break.

It can happen down the other end too, though. This Les Paul took a tumble and broke in a nasty way. The exterior damage is obvious but it's pretty certain that crack extends into the neck tenon too (the tenon's the bit that gets glued into the neck pocket in the body).

This neck needs to come out to be properly repaired.

It's not too often that I need to remove a Les Paul neck, which is lucky as it's a relatively involved job. With a strong cup of tea to steel myself, I set to work.

les paul heel repair frets
les paul neck removal

First up, a few frets need to come out. To remove this neck, I need to soak and steam the glue out and that means getting access to the internals of the neck joint. I do this by drilling small 'access' holes. These are drilled in the fret slots. When it's all done, I'll fill the holes with rosewood plugs and re-cut the slots. All of this is hidden by the refitted frets.

Your eagle-eyes will have noticed a little dot on each (numbered) fret. These frets will be refitted and the dot tells me which is the bass end.

Keeping fingers crossed, I take a look under the neck pickup, hoping for a long tenon. No luck. If I could have seen the end of the tenon, I'd know exactly what size it was so I could position my holes to accurately access the sides of the neck joint  (if it's not clear what I mean here, a photo later on might clarify things).

Since all of this tenon is hidden, I have to measure out the usual Gibson size and position for this guitar and hope that it's built properly to spec.

In the photo, above on the right, you can see the pencil marks I've used to plot out the tenon and the holes I've drilled to get access to the joint.

gibson neck removal
steaming off gibson neck

This one's a bit weird-looking, I'll admit.

In the left image, I'm using a syringe to insert boiling water into the holes I've drilled. I give it a few seconds and then suck it back up again. What comes out is cooler water with some manky-looking dissolved glue. I repeat this process a lot over the course of a couple of days. A Les Paul neck joint is a hell of a strong joint and doing this gives me a little bit of a head start before I hit it with the steam.

Which is what's happening on the right. That nozzle lets me get piping hot steam deep into the joint. The heat and moisture helps to dissolve more glue and, after some time and work, the glue eventually lets go…

les paul neck tenon
les paul neck joint repair

…Leaving most of the bloody tenon still in the pocket. D'oh!

The heel crack extended into the tenon as we thought. Now I have to keep working to get this piece out with pretty much no leverage.

More tea required, I think.

Some steamy swearing later and it's out. Now, in the side of that neck tenon, you can see the tracks of those holes I drilled earlier. We were right on the money with the positions too—nice.

gibson guitar neck tenon repair
les paul neck joint fix

And here's the jigsaw we need to get back together. You'll notice a small shim in the neck pocket. This was installed at the factory (it's not uncommon) and I'll reuse it for this repair.

All of the old glue is cleaned from the mortice and the tenon and then, the two bits of neck are glued back together. Again, the tracks of those access holes are clear in the photo on the right.

gibson neck tenon repair
les paul repair touch-up

Once it's sound again, the neck is reattached to the body. Those frets are reinstalled and all the frets are levelled to ensure clean playability.

Then, it's just some touch-up to hide the evidence. As the rear and neck of this Les Paul are black, the opaque colour easily disguises the repair.

It took a bit of thought, a lot of work and twelve buckets of tea but this job's a good 'un.