Loose Tuning Machine Bushings

How do I keep the small bushing (ferrule) that fits around the tuner's post from falling off?

You may have already noticed that some tuning machine bushings screw to the tuner while others simply press into the holes in the peghead. Well, they're suppose to anyway. Unfortunately loose press fit tuning machine bushings can fall off easily when the strings are removed. With any luck it will hit the floor and roll, usually right to the spot you look for it last!

For screw on bushings we merely tighten them with a nut driver (10mm is a very common size), but for press fit bushings we must address the size of the hole in the peghead.

Comparison of Tuners Using Screw On & Press Fit Tuning Machine Bushings

Common Problems:

• The hole was drilled too large for the bushing to fit securely
• When replacing the tuning machines the replacements are slightly smaller than the original
• Humidity levels have changed and the ferrules have become loose

Martin guitar with Butterbean tuners and loose bushings.

Don't Glue The Bushing To The Peghead

My technique for securing the loose bushing to the peghead does not include gluing it in hole. Why not? First and foremost I simply don't want to alter the instrument. An unsuspecting repair person may wish to remove the bushings in the future, not expecting them to be glued in, and do serious damage to the peghead if precautions are not used.

For Slightly Loose Bushings

When a bushing is only a little loose, layering the sides of the hole with superglue can decrease the size of the hole just enough to allow the press in bushings to fit securely. I call this "padding". 

I apply Hot Stuff Super T medium viscosity superglue in very thin coats until it's thickness has decreased the size of the hole. Because the glue changes the size of the hole, it is not unusual to go from having a hole that is too large to one that is a little too small. If this happens I use a peghead reamer to size the hole just as I would on new construction.

Caution!

While this is a simple repair it is easy to make a mistake that can turn this into a major headache.

Superglue drips easily! A drop of superglue on the finish can turn an otherwise quick and easy repair into a time consuming finish repair. 

Using too much glue or very thin glue may cause it to run down the sides of the hole and pool along the backside of the peghead.

Installing the ferrules before the glue has dried completely could cause the bushing to stick when attempting to test fit.
Obviously, you may wish to have the repair done for you if you are uncomfortable with the idea of practicing this on a valuable instrument.

Glue "pads" the sides of the hole to slightly decrease it's size. Allow it to
cure before installation of the bushings.

For Very Loose Bushings

While that technique is ideal for machine head bushings that are a little loose, those that fit so poorly that they move side to side require more effort. This is usually only a problem if one is installing replacements that are not replica's of the original or when the guitar has had multiple sets installed thru the years which have damaged the peghead hole. In these instances plugging the holes and re-drilling is usually necessary.

This vintage Gretsch Synchromatic guitar has been thru several tuner replacements
leaving the peghead holes oversized and peppered with screw holes.

For more information on Tuning Machine Replacement, visit our site.

 

Neck Resets - Glue Nightmares

Gluing Necks on Acoustic Guitars

Today I am addressing guitar necks that use dovetail joints. 

Sliding a Martin D-18, dovetailed neck out of the neck block after steaming.

What Holds the Neck On?

While glue obviously keeps the neck from coming off, dovetailed joints are designed to slide together, wedge and "lock". When a dovetailed joint is not shaped or fit properly the glue is being asked to do far more work than intended. On many occasions I have seen a loose neck joint blamed on glue failure when in fact, a poorly fitting dovetail was the underlying cause.

I have had quite a few people bring me acoustic guitars that have loose necks. Understandably they are hoping for an easy and cheap fix ...like simply gluing the neck back on. Unfortunately that is rarely the case when doing the job professionally. Dovetails must be shimmed and fit to insure the joint is locking. Simply adding fresh glue to a loose or sloppy dovetail joint would not be a professional repair. (In more transparent language ...it isn't anything I would offer to do.)

Glue Nightmares


Between the chisels and the reamer lay a bottle of Tylenol. I'm going to need it.

Ack Ack! A Martin neck block filled with epoxy.
Yellow lines = this is where the dovetail locks and glue is applied.
Red line = this open area has been filled with epoxy making removal a nightmare.

Above you see a neck pocket that has been completely filled with adhesive, and not just any adhesive ...it was epoxy. After steaming the neck the traditional way I quickly realized it was having no effect. The neck joint only takes a couple of minutes to loosen with steam, mysteriously, this one was still securely set and showed no sign of yielding.

Necks should be glued using water soluble adhesive only. This would include Titebond regular (woodworker's glue) and Hide glue.

Because there was evidence that this fingerboard extension had previously been removed I had my suspicious and removed it to have a looksie.

Another fingerboard which had been 
sawn thru at the 14th fret.

Sawing Thru Fingerboards? That Can't Be Good

Exactly! And that's not the way we do it today. However, once upon a time a far more conspicuous and somewhat destructive method of removing guitar necks was sometimes used. Instead of simply drilling holes down thru the fret slot into the joint, the fingerboard was sawn in half at the 14th fret. This allowed the fingerboard extension to be removed and set aside, exposing the dovetail joint.

While this made the joint physically (and visually) accessible it meant the fingerboard would have to be repaired. And when they were bound it was far more obvious as seen in the picture to the right.

Although this is obviously not recommended it is still a part of guitar repair "history" and something I have seen several times.

Oh Goodie, another one!

The previous repair person had used this method and upon reassembly opted to fill the neck block with epoxy. Oh man ...why me?

Just to reiterate ...a locking dovetail requires very little glue. When I see something like this I assume the individual was trying to use adhesive to keep everything together instead of properly fitting the joint.













Fitting The Dovetail

The arrows point to mahogany shims that I have glued into the neck block where it will contact the neck's dovetail. This (and the fingerboard extension) are the only area's that will receive glue.

New mahogany shims have been glued into the neck pocket and
sanded to provide a locking fit for the dovetail. 

Neck Shims

Shims are required when resetting acoustic guitar necks so the joint can be sanded to fit properly after removal. When a neck is removed from an instrument all old glue is sanded away and the contact surfaces are smoothed, this process removes wood making shims necessary. Even on new construction, shims are often present.

Once the shims are glued in place I begin the sometimes arduous task of sanding and test fitting. I still prefer good old pencil lead as it allows me to see where my joint is rubbing, sand high spots and insure good coupling. Instead of merely placing shims at the tip of the dovetail I create a locking joint which mates from top to bottom.

For more details, you can read my acoustic guitar Neck Resetting article here.

1960 Fender Jazzmaster Guitar Repair

Are You Nuts?


Someone got a bit too creative here, can you spot the problem?

What seems to be the problem with this Jazzmaster?

First ...Do No Harm ...

It's not at all surprising to see something like this on an inexpensive guitar, but when modifications are made that can effect the value of a collectible or vintage instrument you have to stop and ask if they are absolutely necessary. I don't believe there's any question here. :)

Mo' Better!

Apparently a suitable replacement nut was not available (and we all know just how rare Fender style nuts are, lol) so an acoustic guitar nut was used instead.

In order to "make it work", the original nut slot had been enlarged to accommodate the wider acoustic guitar nut. Performing a nut replacement is not difficult, however, this compromise turned an otherwise simple repair into a costly re-repair.

After removing the nut I cleaned the slot and filled it with a splice of matching rosewood. The fingerboard length (distance between the first fret and the end of the fingerboard) was measured before re-cutting the nut slot.

Fret spacing and the correct positioning of the nut and saddle(s) are all necessary for proper intonation. This is why saddle slots, fret slots and nut placement are all performed using precise measurements.

Tusq (aka Graph Tech) makes a variety of high quality, pre-slotted nuts suitable for replacement on Fender Strat's, Tele's, Jazzmaster's, Basses and many others. Purchasing the correct pre-slotted nut helps insure E to E spacing is correct and the strings are properly spaced. When installing a pre-made nut, slot depth is adjusted after the nut is installed. Special files matching the diameter of the strings are used to cut the depth and width of the pre-slotted nut so they match the strings precisely.

Pre-slotted Nut for Fender

The Finished Repair


Fortunately this repair is difficult to spot and the damage has been un-done. Recently I've seen a couple of Fender Stratocasters that were damaged when someone tried to remove the nut and took large chuncks of fingerboard out with it. As theses are generally not difficult to remove I would have to blame the technique rather than the instruments. For a more detailed look at removing, replacing and adjusting nuts see my website.

Fill is barely noticeable and would only be spotted if one knew to look for it.

   

Drilling Holes w/o Chipping Paint

Most electric guitar replacement bodies come without pre-drilled holes for mounting the pickguard, tremolo cover and other trim. Unfortunately when you encounter a finish that wants to chip easily the simple task of drilling a few holes may require more caution.

We can also encounter a problem when an electric guitar body is re-finished and the holes fill with paint.

A new Fender Stratocaster body prior to drilling screw holes.

This articles describes one way that I approach drilling holes in finishes which chip easily.

Place Trim Parts In Position


I start by taping the pickguard and trim pieces in the correct position so I can mark the layout of the mounting screw holes.

It is important to properly center and position our trim pieces to avoid drilling holes too close to the edge of the tremolo or routed cavity. Placing a drilled hole too close to the edge results in a thin wall around the screw hole which can cause it to fail. It is not uncommon for me to find factory screw holes that were placed so close to the edge of a cavity that the screw hole has cracked.

Mark The Spot

I use a sharp awl to make a small impression in the finish to mark the position of the screw holes. Drill bits have a tendency to walk and this impression serves as a "fence" to keep the drill bit centered.

Now I drill a small pilot hole that is much smaller than the hole needed for our mounting screws. This hole will keep our larger drill bit centered and give our countersink's tip a resting spot.

Using countersink to remove finish

Countersink To Prevent Chipping

Finish removed, ready for drilling

I use a countersink for the purpose of safely removing finish. The area should be only slightly larger than the diameter of the final, full size drill bit we need to use.


Cantankerous finishes can chip when the drill bit catches the edge of the finish and lifts it. Having the finish removed means our drill bit will not contact the finish when drilling the final hole.

Drilling The Final Hole

After measuring the screws I will be using I can choose the correct size bit to ensure a good fit. If in doubt, drill a test hole in a piece of scrap wood to test your fit.

Tape serves as depth gauge

Tape wrapped around the drill bit serves as a depth gauge to ensure the hole is not too shallow.

Luckily, not every finish creates a need for such overly cautious steps, but, I tend to treat them all as though it's a possibility and each instrument as though it was priceless.

Gibson LG-0 Plastic Bridge

I have to laugh whenever I read the words "special bridge", but that's what Gibson called their hollow, bolt on, plastic bridges which were used from the early to mid-1960's on their Gibson LG-0 small body guitars.
They were special alright. lol

Plastic Gibson bridge replaced with handmade ebony bridge

These bridges were not glued to the top, instead, 4 screws pass thru the bridge plate and screw into the bottom of the hollow bridge.

Screw holes

Compounding The Problem


Unfortunately the hollow plastic bridge wasn't the only issue this instrument had working against it. Couple the hollow bridge with a soft spruce bridge plate and ladder braces and you begin to understand why many have developed problems.

Excessive top belly (upheaval) 

Loose ladder bracing contributes to problem  

Here we see a Gibson LG-0 guitar which was braced with ladder braces (parallel bracing resembling rungs of a ladder), a spruce bridge plate (most are made with maple or rosewood) and bolt on plastic bridge.

A feeler gauge shows a loose brace which has really exasperated the condition. Without the structural support of the braces the top is free to pull upward and create what we call "belly". While a certain amount of top bellying is normal on aging acoustic flat top guitars, excessive bellying is often an indication of a problem.

Cracked screw hole

Plastic Likes To Crack & Warp


When a top deforms it makes it difficult for the bridge to conform to the changing shape. This can cause the top and bridge to part ways. For a bridge made of wood that means a failing glue joint. On our plastic bridge this means warping and cracking.

Often we see the delicate screw holes crack or completely sheer off as the aging plastic looses it's battle against tension. Gluing and repairing a cracked plastic bridge is a lesson in futility, especially when other issues are present.

A warped plastic bridge

An Interesting Re-Repair

This mahogany topped Gibson LG-0 came into the shop with a replacement bridge already in place. The problem? It was a Guild bridge! Obviously everyone who does guitar repair does not make replacement bridges from scratch. When that is the case they often resort to whatever they have on hand.

While this one certainly looked bad cosmetically, it also produced very poor intonation. The instruments saddle slot must be precisely located to allow the instrument to play in tune up and down the neck.

LG-0 that had a Guild bridge installed. Note the original screw holes.

With the Guild bridge removed I was faced with a large area where the finish and some wood had been removed. This area would have to be touched up as a complete top refinish was not in the budget.

I created an oversized ebony replacement bridge to not only cover some of the  previous damage caused by the Guild bridge, but it also added additional mass behind the bridge pin holes. Look again at the plastic bridges and see how closely the bridge pins sit to the back edge of the bridge. That may work on plastic but it isn't going to cut it on a wood bridge.

An oversized ebony bridge is used to conceal the damage done by the Guild bridge

See my photo gallery of bridge replacements

Loose Strap Buttons on Input Jacks

Most acoustic guitar pickups use a long input jack. The strap button screws directly to the input jack but often comes loose with repeated removal and re-installation of the strap.

String Creaks When Tuning

Complaint : When tuning my guitar I hear a creaking noise, like a pinging sound whenever I turn the tuning key.

This sound is usually caused when the string itself is encountering friction. As an instrument is being tuned the string is being pulled ever so lightly over the nut and saddle, any resistance at these points can cause a distinct creaking sound.

Take a good look at :

• The nut slot
• The saddles surface
• The strings path across the peghead

Most often the culprit is the nut slot. A nut slot that is too small for the diameter of string passing thru it can catch the small windings of the strings and cause noise when tuning.
On many classical guitars (or those with slotted pegheads) the strings angle to the nut slot can also cause the string to come into contact with the inner edge of the peghead.  I have also seen some instruments who's tuning machines lay at such an angle to each other one string could actually rub against the next tuner.
 


Solutions: The nut slot should be cut properly with a nut file or polished properly to eliminate binding.
The use of a string lubricant or "Nut Sauce" in the nut slot may also decrease friction.
Saddle surfaces should also be examined for grooves and polished where necessary.

Exceptions: It is not uncommon to have difficulty completely eliminating this on certain instruments. Slotted pegheads put the string at an increased angle as it crosses the nut, increasing the tension on the nut. It is also my experience that certain softer nut materials become easily grooved and must be repeatedly addressed.

Finding Loose Guitar Braces

Signs of a loose brace:

• Vibration sound
• Squeak when light pressure is placed on top or back
• Non-symeterical arching on top or back (lump to one side)
• Excessive top bellying
• Top Rotation (severe belly behind bridge with a dip in front of the bridge)

No need to point this loose brace out to you.

A quick peek inside was all it took to find the buzzing culprit on this guitar.

But not all loose braces are as easy to spot, in fact, some loose braces fit so closely to the top/back that it's hard to see a gap visually.


I like to run a thin feeler gauge along the glue line of the top and back braces to ensure we aren't missing a loose brace that visually looks unsuspecting.

Tying Nylon Guitar Strings to Tieblock

This video shows how I tie the strings to the bridge on nylon string and classical guitar tie block bridges.