instrument repair

Stuck Stuff: Removing tun-o-matic Bushings

Stuck Stuff: Removing tun-o-matic Bushings

It’s occurred to me that a lot of a guitar repairer’s time is spent removing things from guitars. Sometimes that just involves unscrewing some screws but, other times (often?), some additional effort and knowledge is required to safely remove something. 

Like various ‘bushings’. Read on…

Loose Strap Button

It's not too unusual for the strap button on your guitar or bass to become loose.  They can take a bit of punishment without your even realising it. Many of you will be familiar with the 'matchstick trick' where you can insert a matchstick (preferably spent) or toothpick or similar into the worn screw-hole and re-screw the button back on.  This can get you through a few gigs or even a bit longer but it shouldn't really be considered a permanent solution—it could get embarrassing when your strap flies off as you're doing an Angus Young duck-walk across the stage.

The best thing to do is to plug the worn hole completely and re-drill a new screw-hole into fresh wood.

The hole shown here has been let go a bit too far.  It's had matchstick after matchstick inserted and all that (ahem) screwing has worn away more wood than usual.  This one is a bit of an extreme case.

To put it right is the same principle though.  Plug and re-drill.  In this case, I'm actually going to drill the existing, worn, hole a little to clean it and get rid of the taper that it has.  This will allow me to insert a decent piece of new wood that will hold the strap button for the foreseeable future.

In the image above is the piece of mahogany I'll use. I like to match the plug to the guitar wood if possible and I think it's better to use hardwood plugs rather than those softwood dowels you can get in the hardware shops. The only drawback is that I generally have to shape a plug. It's not that big a big deal though, and it gives a better repair.

I'll drill this hole out a bit—it won't be wider than it is at its mouth and it'll be covered by the strap button anyway— and shape that mahogany to fit. Then, I'll glue it in and let it set.  A new screw-hole is drilled and the surface given a dab of lacquer to protect the fresh wood (we're not talking refinish-quality here as it's all hidden anyway).

Once done, the remounted strap button should be good for plenty more years of service.

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
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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

Wood-Bending for Fun and Guitar Repair

Acoustic Guitar Repair

An acoustic guitar with a dodgy, onboard preamp that had to be replaced. What should have been a straightforward job became a little more complicated becauset the original preamp had a particularly large footprint. It was an older, discontinued model and the manufacturer was unable to supply a replacement that was as large. As it turned out, it was pretty difficult to find any manufacturer that had a unit that would cover the existing hole (and patching and recutting wasn't favoured for cost reasons).

After quite a bit of internet rooting, a unit was found that would cover the hole in the guitar's side. Great.

Just one problem though… Although the bezel covered the hole, the mounting screws were located such that the front two had nothing to screw into (see the locations marked on the blue masking tape).

Guitar Repair - Acoustic side patch
Guitar Repair - Bending wood for side patch

The solution: glue in some wood for the screws to mount in. As this is the shoulder of the guitar though, the wood patch needs to be bent, or curved, to mate properly with the guitar's side.

No problem. Out comes the trusty bending iron. I cut a piece of mahogany a bit larger than needed for the final patch as tiny pieces are very difficult to bend. Even larger pieces need gloves as that iron gets hotter than the surface of the sun. Making sure to keep the mahogany damp, I gradually worked the wood until the heat and steam loosened the fibres—you can feel this happen. Then, working along its length, I bent the piece to the right curvature to match the guitar shoulder.

Instrument Repair - Acoustic guitar side fix
Instrument Repair - Acoustic guitar preamp

Once it was there, I clamped the bent wood in an acoustic mould (I picked a suitable position to mate with the bent wood) and waited for it to cool and dry. I could then cut it to shape and glue it in place.

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The sides of an acoustic—and in particular, this area—play a very small part in its overall tone. This is why it's possible to cut bloody, great holes for preamps in the first place. This patch is not going to have any effect on the guitar's sound. It will, however, allow the new preamp to be mounted and will get this guitar gigging again.

January's Guitar & Bass Setup Sale At An End

Guitar And Bass Setup Sale

Guitar And Bass Setup Sale

January is over and the Ridiculously Mental January Setup Sale is at an end. And it was fairly mental.  January passed in a whirring blur of setups. It was a bit like one of the training montages from Rocky IV, just with guitars instead of logs. Oh, and less cheesey music. My setup muscles are looking pretty good though.

I still have a bit of a backlog of January instruments to get through but the next week should see the last of the half-pricers back with their owners. Thanks to everybody that's allowed me to work on their instruments this month – I hope you're happy with how your babies are playing.

Of course, the sale may be over but I think even the non-crazy setup cost is pretty reasonable. If I can help you out with your guitar woes, feel free to drop me a line.

What To Do If You Break Your Guitar's Neck

I've written a little about specific headstock repairs and it occurred to me that might be a good idea to give you an overview with some tips  and considerations on how to prevent broken necks and what to do if the worst happens.  It's a little long but could well prove useful to know…

The worst thing in the world?

You're finished the gig and you're enjoying a well-earned beer at the bar. You're careful to keep an eye on your pride and joy, propped up against your amp on stage, to make sure nobody swipes it. It's safe though, the drummer's up there packing up his gear.

Wait! The drummer's knocked against your amp with his fat arse*. Your guitar tips, slowly, very slowly, it's going, it's going… And it's gone. It hits the ground and the headstock keeps going. You can hear the crack over the noise of the crowd.

Is there anything worse?

Of course there is, but for a guitarist this is one of life's grimmer moments. A broken neck. You fall to your knees, hands imploring the heavens, and bellow, "Noooooooooo!" The security guy eyes you suspiciously.

Why? Why? For Clapton's sake, why?

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How could this have happened? Well, you could possibly go so far as to call it a design flaw. On any guitar with an angled-back headstock, the area where it angles is naturally weak. This is because of a number of factors but primarily to do with the timber's grain direction and the fact that the area is pretty thin - the thinnest part of the neck. Add to this the fact that many instruments have a truss-rod access channel here, effectively removing even more wood from an already weak area, and you have a recipe for breaks.

The image on the left shows a Les Paul neck/headstock. I've added a dotted line to indicate, approximately, the depth that the truss-rod access cavity is cut. You can see there's not a lot left.

Many guitar makers try to alleviate the potential for trouble in this area with a variety of means; multi-ply 'sandwich' necks, truss rod-access moved elsewhere or reduced, scarfed headstocks, and the most common, a volute. A volute is simply a shaped/carved 'bulge' that's left in the weak area to strengthen it (although it might be more accurate to say 'not to weaken it').

Gibson are frequent stop-outs on this though. Although a volute was introduced on many Gibsons in the late '60s, it was phased out again and it's appearance on modern Gibsons is hit-or-miss. Most don't have one. Indeed, while all instruments with angled headstocks have breakage potential, Gibsons (SGs and Les Pauls in particular) top the charts in the headstock repairs I perform. If Gibson ever start strengthening this area, guitar repair guys all over the world are going to see their incomes drop.

My guitar neck is broken. What do I do?

If you do manage to break or crack your guitar's neck or peghead, don't panic. Almost anything is repairable. Here are the immediate steps to take.

  1. If the headstock is still attached to the neck (the headstock veneer often keeps it attached), gently - very, very gently - slacken off the strings. Pop it in it's case and get yourself to a good repair guy.
  2. If the headstock is just cracked, do the same - slacken off and get it repaired.
  3. If the headstock is completely detached, carefully wrap it up in something (a bag, newspaper, etc.) and try not to knock, damage or disturb those jagged splinters of wood poking out.
  4. Don't try to fit the headstock back to the neck as the joint should usually be examined and cleared of any misaligned splinters or loose timber before this is attempted.
  5. Check for any splinters that have come loose and if you find any, pop them in a bag - they'll help complete the jigsaw and assist in getting a good, clean repair.

Repairing a broken guitar neck

The first repair is the important one. If it's not done well, then you've got a reasonable chance of the guitar breaking along that fault again. Sometimes string tension alone can be enough to pull a badly repaired break apart. And, repairing along a previous repair is much more difficult, time-consuming and often more invasive. Not to mention more expensive.

The lesson? Don't break your guitar neck but, if you do, get it repaired properly first time around.

Talk to your repair guy and ask him/her to discuss the repair. A good repair guy will be happy to chat about their plans. What glue will be used is important for example. For most repairs either hot hide glue or aliphatic resin is the right choice. If your repair-guy decides immediately to slap in a load of epoxy, you might want to ask them why. While epoxy certainly has a place in headstock repair, it's generally a limited one. Epoxy is incredibly strong if used properly but its nature makes it difficult to penetrate cracks and it's not usually a first choice adhesive for most of these jobs.

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The majority of broken necks tend to be relatively straightforward. Some, however, require a bit more effort. 'Short' breaks across the neck or the headstock that allow very little 'glueing' surface will often need to be reinforced. Reinforcement may involve glueing in new pieces of wood, called splines, that extend beyond the break and provide additional strength.

Other reinforcement methods include the use of 'overlays'. A back-strap or front-strap overlay is a veneer of wood that gets glued on to the back or front of the headstock and will often extend down into the neck area (as shown in the diagram). It's necessary to remove existing wood from these areas to fit the overlay and the newly-glued overlays must be drilled for tuners and so on. Refinishing the area is also necessary. Overlays take a lot of work but can often be a relatively discrete way of reinforcing a break.

This sort of reinforcement is often necessary for repairing previously-repaired breaks (i.e. second repairs) too, as it's often not possible to get a clean joint on on a break that's been glued before - that's why it's important to get it right first time.

Prevention is better than cure.

Almost all headstock cracks and breaks are caused by the instrument falling. If everyone put their guitars into their cases after they were finished playing or gigging, I'd be able to afford less beer every month.

Cases are not a guarantee - I've seen a headstock break after a fall in a case - but they certainly get you most of the way there. A good-fitting, hard case will protect your guitar from most things. If you wanted to be a bit anally-retentive about it, you could slacken the strings off before stowing your guitar but that's probably overkill for most people (although you should definitely do so if you ever have to ship your guitar anywhere).

If it's too much of a pain to put your guitar away, get a decent stand or locking hanger. There are even hangers that can attach to your amp combo or cabinet now. Stands and hangers obviously won't give you the same protection as a hard case but they're better than just leaning your guitar against your amp (no matter how cool that might look).

The upshot

Protect your guitar and you might never have to get its neck repaired. If the worst happens though, don't panic - things can be put right again. Make sure you trust whoever is repairing the broken neck though - the only thing worse than having to get your neck repaired is having to get it done twice.

If you've any questions, feel free to drop me a line. I'll do my best to answer them.

*With apologies to drummers everywhere - I'm a bad person, going for the easy laughs. ;-)

Guitar Repair: Pre-War Martin Acoustic

Martin Acoustic Guitar RepairOne of the great things about repairing guitars is that, every so often, you get an absolute beauty through the workshop.  This was one of those guitars.  It's a pre-war Martin and it's just fantastic. It's had a few bumps and scrapes over the 75-odd years of its life but it plays beautifully and sounds amazing.  This guitar has the blues seeped all they way through its mahogany and rosewood and when you play, it seeps back out again.  Brilliant. This is one of the, occasional, instruments that I hate giving back to the owner after it's been repaired.

Anyway the issue with this was a broken bridge.  The wood in front of the saddle had snapped off (and not for the first time as evidenced by signs of a previous repair).  After discussing the options, the owner settled on having a replacement bridge custom-carved for his baby.

In a three-part article over at the Guitarless blog, I step through the process from making this decision with the owner to removing the damaged bridge, carving a new one and replacing it.

Have a look here.  Hope you like it.