fix

Headstock Repairs - Reinforcement

Broken Gibson headstock repair

We've talked a lot about neck resets over the last few weeks so let's move down the other end of the neck. Headstock breaks.  

Nobody likes to see it happen but sometimes your guitar takes a tumble and the impact can—all too easily—snap the headstock. In most cases, this is a (reasonably) straightforward repair and can be re-glued soundly.  

Sometimes, though, the nature of the damage can force us down a more 'involved' path. If the break is 'short' (i.e. it doesn't provide a lot of glueing area to ensure a sound repair) it may be necessary to consider some reinforcement to ensure the repair holds.  

One solution is what's called a 'backstrap overlay'.  

This involves overlaying some fresh wood over the repaired break. The new wood glues onto the unbroken wood either side of the crack to add strength.  

Let's take a look at one. 

Reglue headstock before applying backstrap

Remove wood to accept overlay

In the first photo directly above, I'm repairing the break. This might seem odd but I need to get everything back together properly before I apply any reinforcement. The repair is carried out as it would normally be since the actual re-gluing isn't the real problem—the problem is keeping it in one piece after string-tension is applied. I need to glue-up everything as normal and then reinforce things to ensure the repair is strong.

When the initial repair is done and the glue has dried, I can begin the real work on this one. I remove a few millimetres of wood from the rear of the headstock and, past the break, along the neck. It would make for a more discreet repair if I brought this all the way to the end of the headstock but, on a Gibson, I like to stop short of the serial number. If the guitar is ever sold on, a perspective buyer may be put off more by the lack of a serial number than a well-executed repair. 

The photo above on the right shows the removed section. I'll inlay the new wood here so let's get on with that.

Clamping for backstrap overlay on Gibson neck break

New wood overlaid over broken neck

The wood to be overlaid on the headstock is thicknessed and cut to the rough dimensions. To accommodate the angle between headstock and neck, I bend the new wood. It's this bending that adds extra strength to this repair as the wood grain curves to the correct angle.  

Repairing guitars often makes for some intricate clamping setups and overlays are prime culprits. A shaped caul is useful to get the wood in that curved bit glued in properly. The roughly shaped wood overlay is pretty obvious (and pretty ugly at this stage) in the photo on the right. 

Newly inlaid wood cut to shape on headstock

Tuner mounting holes drilled in overlay

This is where things take shape (pun intended). The overlay is cut to shape and the tuner holes drilled.  

At this point I can go through the usual finish prep. Grain-filling, sanding, etc. In cases like this I need to match the colour of the original finish on the newly overlaid wood. I also have to manage the transitions between new and old finish carefully to keep things looking as inconspicuous as possible. Sealer, colour, and a number of clear-coats later and I'm ready for the next step. 

Waiting.  

Have to wait for the finish to cure properly. Then sanding and buffing and polishing and reassembling and stringing-up and… 

Playing. 

All is well with the world.  

Gibson headstock break repaired with backstrap overlay

Les Paul neck repair with reinforcement

Gibson Neck Reset - Curveballs

The last word on neck resets for a little while. We've had the theory. We've had the straightforward neck set on a Martin and we've had the Martin neck reset that fought back a little. 

Let's take a look at a neck reset that threw up some curveballs along the way. 

On a Gibson acoustic guitar, the job of getting the neck off is generally a little more work. As well as glueing the actual dovetail joint, the folks at Gibson also apply glue to the surfaces between the neck-heel and body-sides. Also, they glue the neck in and then  lacquer neck and body together. This means getting through the lacquer safely when removing the neck, and—more often than not—means some light finish repair work after it's all reassembled. A Gibson is more work to reset but is still generally straightforward. 

Generally… 

First up, this guitar has a couple of longitudinal cracks in the top. These have been there a while and have had a previous repair before I got the guitar. I check the repair and it seems sound so I move on. I also note that there is a small gap between the bottom of the heel and the body-binding. I can't tell too much about this now and it's clearly been there for some time so I pop it in the mental notebook.

I won't go into detail as I've covered much of this before. I free up the fingerboard extension, drill my steam access hole and get to work. 

Something's not right.  

As soon as I give the instrument its first 'encouragement wiggle', I can tell that something is wrong. 

Applying steam to loosen glue on neck dovetail

Applying steam to loosen glue on neck dovetail

Neck block has come loose internally

After some investigation, the issue becomes clear. The neck block (the solid hunk of wood that supports the neck inside the guitar) has become loose. The guitar's top and back are no longer glued to the block and any pressure I might apply to remove the neck is also going to push the block up against the top until it breaks.

It seems likely that the existing top cracks happened either because the block was loose and not properly supporting the top or (more likely) occurred at the same time as the block became loose—probably in a fall. Either way, I don't want to make things worse. 

You'll notice in the photo above right that I've removed the fingerboard extension (and that palate knife shouldn't be able to slide in like that). However I proceed on this job, I need to re-glue the neck block but I'm now concerned about unduly stressing this guitar top any more than is completely necessary. Removing the fingerboard extension will allow me to support the top as I remove the neck. 

Re-glue acoustic guitar neck block

Supporting guitar top while removing neck

You can see that support in the photo on the right. The dovetail-shaped slot cut in some plywood lets me ensure that the top doesn't move as the neck joint is separated. That separation is a slightly slower job now, and a more careful one.  

Once the neck is out and I've cleaned up the joint, I can glue the fingerboard extension back on to the neck (using a sliver of rosewood to take up the space of the fret-slot I used to cut through. This slot will be re-cut after things are back together. I go though the normal neck reset process from here.  

Dovetail and socket 'mismatch'

This Gibson has one more curveball to throw at me though. As I alter the neck angle, the bottom of the joint becomes looser in its socket than I'd generally have expected (a little is quite normal). Turns out, this dovetail's not the best fitted joint I've ever seen. The dovetail (the male part of the joint) is quite a bit shorter than the socket it mates to. I'm going to hazard a guess that this may have contributed to that little gap between heel and body-sides I mentioned earlier. 

Not a major problem. Some shimming is pretty much always necessary during a dovetail reset. Done properly and I've got a heel that contacts perfectly all around.

Better than original. Nice. 


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.

Bespoke Bridge

IMG 2959

Let's be honest, that's not an attractive bridge. It's seen a lot of action over the years and it's cracked and, somewhere in the distant past, it's had some gunky filler splodged in to try extend its life. And it's actually a slightly odd bridge. Although it has six holes for bridge pins, you can see along the back there are some filled holes as if this bridge were once strung from the top. There are also two little pearl dots which are usually present to hide small bolts (as they do in this case). These bolts are generally used on bridges that string from the top. But, then, why the bridge-pin holes?

It seems likely that the manufacturer repurposed this bridge from another model, filled the string holes and installed with bolts as normal. Fair enough.

This is all an aside anyway. On to the real work.

The owner wants this sorted but I wasn't able to source an off-the-shelf replacement. This means custom-malking a replacement.

custom acoustic guitar bridge
acoustic guitar bridge fix

Getting these things off is a pain—as well as the two little bolts under the pearl, this manufacturer epoxies the bridge in position. I may have used swear words.

Once off, though, I grab a nice piece of rosewood and thickness it to about the right height. I carefully measure and mark off the important dimensions, particularly the pin holes and the bolt holes—if these are misaligned or misplaced, the bridge has to go in the bin.

Some careful drilling and we're ready to shape the bridge. In this case, it's a (relatively) easy job as the original doesn't have a lot of sharp edges to curves that need to be replicated. It's easier to replicate those sweeping lines.

glue acoustic guitar bridge
acoustic guitar custom bridge

Re-attaching the bridge, in this case, means epoxy again. There's a major risk of the bridge sliding about as it's clamped so some very careful preparation was necessary to ensure this didn't happen. Pin-holes and the bolts came in useful in this.

And, you can see the end result in the last image. As it's a nicer piece of rosewood, I think the new bridge actually looks better than the original but, that aside, it's certainly more sound.

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.


Christmas Opening 2012

haze guitars instrument repair dublin

It seems like my internal organs have barely recovered from last year and Christmas is here again. Ho ho ho.

While it would probably be cheaper just to pay someone to kick me repeatedly in the liver for a week, it is traditional to take a little time off to ruin my health the old-fashoined, Irish, way.

With that in mind, Haze Guitars will be closed for the Christmas period. Other than a couple of collections I've already arranged, Haze will be closed from 23rd of December until the 2nd of January.

I will be answering the occasional email as family/turkey sandwiches/hangovers allow so feel free to drop me a line. 

Come January, I'll continue to follow tradition by holding the Great And Marvellous, Definitely Going To Kill Me This Year, January Setup Sale. More info on this—and some other exciting news for January—over the next week.

As I always do at this time of year, I want to say an incredibly massive thank you to everybody who's trusted me with their instruments over the last year. I know what it means to hand over your precious and I genuinely appreciate your trust. I hope I was able to help.

Thanks for everything this year, and have a great Christmas.

Extended Saddles and the Curse of a Good Ear

guitar saddle extended

I rambled on about acoustic guitar intonation a while ago and mentioned that sometimes, the proper intonation point for a particular string falls somewhere fore or aft of the actual saddle. In some cases, all of the instrument's other strings do likewise and this can be an indication that the saddle slot may be in the wrong place. Often, however, it's just one outlier. One lonely string, steadfastly blazing its own out-of-tune trail. An intonation maverick, if you will.

It's not always a big deal. Perhaps it's just a little out or, perhaps your ear/brain isn't particularly bothered by it. However, if you're one of those cursed with tuning-sensitive ears or if your poor, perfectly-pitched brain screams in discordant agony when you play certain chords or intervals, you might want to consider drastic action like this.

Well, it's not terribly drastic, really. I've made a new saddle for this tenor guitar from a bone blank and all strings except the third intonated quite happily. The delinquent string wanted to intonate miles away from the saddle.

So I extended the saddle.

There are a couple of options for this but the most straightforward is an additional piece of bone that's been glued to the rest of the saddle. It's half the height of the saddle itself—it lacks a 'bottom' half and it actually rests on top of the wooden bridge so it's completely reversible (just pop a new saddle in). It gives me the additional scope needed to shift this string's intonation point forward.

Looks odd but sounds much better.

Acoustic Guitar Intonation

Intonation guitar

Time to break up all this Burlesque talk with something a little different. What's going on here, then?

Intonation. It's a bug-bear for some. We could talk about equal temperament concerns and mathematical subdivisions of scale-length and whatnot, but it would get dull quickly. Suffice it to say, tuning on any fretted instrument is always a little bit of a compromise.

In order to try get the damn thing to sound as closely in tune as possible, we 'intonate' each string to compensate its length so it sounds right when fretted. On most electric guitars, we do this by adjusting the string's saddle—moving it backwards or forwards to slightly lengthen or shorten the string's sounding length. Easy-peasy (unless it's a Floyd Rose-type bridge in which case it's more annoying than being repeatedly kicked in the shin by a crying child in a restaurant).

Acoustic guitars offer a bit more of a challenge than most electrics though.

An acoustic guitar generally has a fixed saddle (of bone or whatever). The fact that the saddle is installed at a slight angle (increasing string length from 1st to 6th) string is a nod towards some string compensation. The pre-shaped, compensated saddles that many guitars have these days is another step in the right direction.

For most people (and most guitars and strings) these get close enough that tuning issues aren't glaringly awful.

Sometimes, and for some people (depending on playing style and the curse of having a good ear), it's not enough.

make acoustic guitar play in tune
intonate acoustic guitar

Intonation depends on precisely seventeen million variables. Well, give or take—there are a lot of factors that all interact to determine the best setting. Tweaking setup and string choice can help if there are problems but sometimes that's not an option or isn't sufficient.

What's going on in the images above is that I've used little chunks of rosewood to individually intonate each string on this acoustic guitar. The saddle has been removed and the rosewood is acting like an individual saddle for each string. I poke it back and forward to find where each string properly intonates.

StewMac actually offers a doohickey that does this without fiddling with bits of wood. I've been threatening to get one for a while but I'm forgetful and tight.

Popping a piece of cellophane over the bridge lets me mark the location of each intonation point and the actual saddle location itself. This gives me an indication of where each string should sit on the saddle to sound best. It's easy to transfer this to a new saddle blank.

This guitar, its setup and strings, actually indicates a complication: As you can see in the image in the right, some of the optimum intonation points sit outside the actual saddle.

This happens sometimes. On an older guitar, it's not unusual to have a saddle actually misplaced. This can necessitate filling the slot and actually re-routing it in a new position. That doesn't tend to happen so much these days but, depending on other factors, it's possible that one or more intonation points might be in front of, or behind, the saddle.  Of course, making a much wider saddle is an option but that adds expense and entails modifying the bridge to accommodate that wider saddle.

custom carved acoustic saddle

The other option is compromise (we're back to that word again). In this case, carving a new saddle with intonation points as close as possible to those measured will improve things considerably. Four of six strings will be pretty much perfect and the remaining two will be a lot closer to perfect than they originally were. Overall, it sounds much more in tune than it did without the need to irreversibly modify the bridge to accommodate a wide saddle.

So, we end up with a slightly odd looking saddle that sounds a lot better and the original is safe in the case in case it's ever needed. Not too shabby.

It's worth remembering that this is probably overkill for the majority of people. Most guitars and guitarists are generally ok with the regular or pre-compensated saddle. Failing that, a good setup or a change of string-gauge will probably get you close enough that you'll be happy. If you're still hearing problems though, a custom-compensated saddle might be an option.

Wobbly Jack Syndrome

If you've had a Telecaster for any length of time, there's a reasonable chance you've experienced Wobbly Jack Syndrome. It's an annoying condition that afflicts Teles from time to time. You know it… That little recessed metal dish or cup that holds the output jack starts to get a little loose. After a while, it's very loose and—sometimes—even causes nasty signal cracks and output loss.

Inside the hole in the side of the guitar, the output jack is mounted through a metal 'retainer clip' and the metal cup. The retainer clip (photo on the right below) should hold it all tightly in the wall of the hole but sometimes works its way loose.

wobbly telecaster output jack
telecaster jack retainer clip

The clip works on a really simple principle: it goes into the hole with its sides bent (as shown above) and is forced to straighten. This causes the sides to dig into the hole-wall and holds it all in place.

Easy. And it's an easy fix if you have the right tool. If you don't—despite the easy principle—it's almost impossible to do properly.

telecaster jack repair

And that ugly looking hunk of metal in the photo on the left is the right tool. Leo Fender may have given it a proper name but, for me, it's just the Tele Jack Clip Installation Thing. It makes it easy to remove an existing clip or to properly install a new one. Without it, you end up hacking aimlessly and hoping for the best.

If you're fed up with wobbly Tele jacks, a device called an Electrosocket can be screwed in to replace the, rather fiddly, clip and cup arrangement. It's not something you'd really do with a nice vintage Tele, though. In that case, occasional wobbly jacks are just part of the magic.

Neck Correction: Back-Bow Baby

It's certainly been mentioned a few times around here that the strings on your guitar exert quite a bit of tension on the neck. Enough, usually, to pull the neck into a 'bow' shape (with the middle being farthest from the strings). Our trusty truss-rod can generally be called on to counteract that tension and to control the bow or even straighten the neck completely against the string pull. Sometimes, however, we get what's referred to as 'back-bow'. With a back-bowed neck, that bow shape is effectively reversed and the middle has ended up closest to the strings. This means that a note fretted in the lower end of the neck can't sound clearly as it hits off the 'uphill' frets all the way to the middle of the bow.

There are dual-action truss-rods available and these are able to correct for back-bow as well as, the more normal, forward bow. They're becoming more common but lots of guitars still have the usual single-action rods that can only correct forward bow to counteract string tension. As this is what it needs to do in 99 out of 100 cases, that's generally fine.

But sometimes it's not.

guitar neck relief correction

Setting up this guitar, I found it was back-bowed beyond the point where string-tension would have corrected it. Open notes and those as far as the eight fret or so all choked or buzzed. Even with the truss-rod slackened off completely, the neck wouldn't pull straight or into relief (a very slight bow).

There are a number of things that could be done to try to address this, some of them relatively involved jobs. Before getting into those discussions regarding what isn't really a super-expensive guitar, I had a punt at a quick-fix. This doesn't always work and isn't always suitable but it's certainly worth a go in this case.

In the first photo, I've got my heating blanket sitting on the neck, weighted down by a heavy fret-leveller. I don't want to go nuts with the heat here. Too much will just cause hassle in this case but I'm applying sufficient heat to slowly heat the glue holding the fingerboard to the neck. I don't want it to completely let go; just to soften slightly.

correct back bow on guitar neck

When I think it's where I need it to be, I clamp the neck into a bit of a forward bow and leave it to cool. If things go to plan, the glue will re-harden and help the neck to hold some of the shape I've forced it into.

And, luckily, things went to plan. Unstrung, the neck now has just the slightest of back-bows and, under string-tension, that pulls into a little relief—enough to get it playing nicely again.

Incidentally, a workplace safety tip: Even if you are fully aware that this procedure will leave your steel fret-leveller in a very hot condition and, even if you wear heavy gloves to move it, you shouldn't put it over to the side of your workbench, right where your elbow will touch it when you're checking clamping pressure. That would be stupid.