Acoustic Guitar Care

How to Identify Dead Frets

Checking Fret Height with Fret Rocker

If you are hearing dead spots on your guitar neck e.g. a ‘dead’ note that can’t be heard when the note is fretted, decays rapidly or you hear a buzzing sound, chances are you have a dead fret. Fear not, however, dead frets can almost always be resurrected. In the following article, we’ll discuss the most common causes of dead frets and show you how to identify them.

Dead frets can have numerous causes. Including uneven or loose frets or insufficient neck relief. Another cause can be the guitar dampening specific frequencies (sympathetic resonance) which can be fixed (in some cases) by applying weight to the headstock ultimately changing the way the neck vibrates.


Resonant Dead Frets

Sympathetic Resonance

Sympathetic resonance occurs when something vibrates and something nearby vibrates in response due to being ‘sympathetic’ to the same frequency. What this means is that the second object responds to the first object and vibrates at the same frequency.

If for example, you have two tuning forks and strike one of them, the other tuning fork (being sympathetic to the same frequency) will also begin to vibrate.

Tuning forks displaying sympathetic resonance


Sympathetic resonance can be extremely powerful and even has to be factored into the design of buildings.



When it comes to maintaining your guitar, a dead fret caused by sympathetic resonance occurs when you play a note and another part of the guitar vibrates at the same frequency, absorbing the energy of the note, forcing the note to decay rapidly.

Of course, this can also go the other way, in the form of wolf notes. A wolf note is almost the exact opposite of a dead fret, expanding the overtone frequencies of a note, and making the note louder.

You can test whether sympathetic resonance is the cause of a dead fret (or wolf note) easily by simply detuning the string you are hearing the problem on and then rechecking the position of the dead fret.

If the location of the dead fret changes relative to the amount of tension placed on the string, you can safely rule out a physical issue such as uneven frets.

Fixing Sympathetic Resonance

In some cases, you can fix a dead fret caused by sympathetic resonance by changing the weight at the headstock. This may be fixed by adding something as simple as a clip-on tuner, changing the tuning pegs, or using a product specifically designed for this problem.

Fender makes one particular product known as the Fender Fatfinger, which is a weighted clamp designed to increase sustain and reduce the occurrence of dead frets.

In other cases, guitarists accept that guitars are made from wood, which being organic has unique characteristics that in some cases we need to work around e.g. becoming more proficient at muting/dampening. It depends on the extent of the problem.




Fret Dressing

A low fret wire causing a dead fret

Another cause of dead frets is badly worn frets. This tends to occur on older guitars that have been played a lot.

Over time, one fret (usually in a position of the neck that is played most often), will become worn in comparison to its neighboring frets. In this instance, it’s better to replace the fret rather than level the remaining frets to the same height.

Compared to a complete refret, swapping out one fret will be considerably less expensive.

In other cases, the top of the fret (the crown aka the bead) becomes worn increasing the surface area of the fret wire and creating a larger point of contact for the strings. This allows the string to vibrate against the fret wires, which in turn absorbs much of the energy of the note.

This won’t necessarily create a classic ‘dead note’ but it can create additional problems including fret buzz, poor intonation, and result in you going through guitar strings faster.

Ideally, your frets will be crowned to reduce the contact area at the top of the fret. Unless you know what you are doing and own the necessary tools (notched straight edge, fret file and/or leveling beam, crowning file, or 3 corner file) you will be best served to take your guitar to a luthier, or at least practicing fret dressing on an older, less valuable guitar.

Fret dressing is challenging work and requires a great deal of patience. It’s not something you should do on a guitar you value if you haven’t done it before.

If you take the guitar to a repairer or luthier they can assess the entire neck and let you know if the guitar would benefit from a complete fret dress e.g. leveling all the frets, along with crowning and polishing. Doing so helps the string glide over the fret wires when bending notes, making a guitar feel like new again.

Uneven Frets

In the majority of cases, a dead fret will be caused by a physical problem with the guitar’s fretboard, resulting in one fret sitting higher than its surrounding frets.

This can be caused by insufficient neck relief in which case you simply need to check the straightness of the neck and adjust your truss rod accordingly. Other causes include loose frets which we’ll address below and uneven frets due to the frets wearing at different rates.

Checking and repairing loose frets

The simplest way to check for loose frets on your guitar’s fretboard is to take a small block of timber and press it firmly against the ends of the fret wires. If you detect any movement you have a loose fret.

In some cases these can be pressed back into place or tapped using a fret hammer (or small mallet), however, you may also need to apply super glue.



If doing this yourself, use thin super glue which will provide better penetration, and apply directly to the fret slot (the channel the tang of the fret wire is seated within) using a toothpick or similar small item. Take care not to get any glue on your fretboard by masking the area first.

Checking for high frets, causing dead notes using a fret rocker

High Frets

If you have ruled out sympathetic resonance, the neck relief is fine, and you have checked for loose frets then the cause of your dead fret is likely to be an uneven fret caused by uneven fret wear.

This is perhaps the most common cause of dead frets and is simple enough to identify but you will require either a fret rocker or a short straight edge rule (you can also use a credit card if you have nothing else available).

Fret rockers are simple tools with three sides, all of different widths. The fret rocker spans three frets on the guitar’s neck. If the fret rocker can ‘rock’ back and forth at all, it means the middle fret is higher than the two outside frets.

When checking fret height, be sure to check each fret and run the fret rocker across the frets to ensure there are no uneven spots, rather than the entire fret being higher than its surrounding frets.

The three different lengths are used to span three frets as you move further up the neck. Generally, the longer side is used up to the 11th – 12th fret but once past the 12th fret as the frets become narrower you will need to use the two shorter sides of the rocker.


Fixing High Frets

Once you have identified the high fret, the height of the fret must be reduced to the same height as its surrounding frets. This can be done using a fret file, before crowning and polishing. But, unless experienced or working on a less valuable guitar, I would recommend taking your guitar to a luthier. Fretwork is specialist work and is beyond the scope of this article.

If you haven’t done this type of work before you run the risk of causing damage, that would otherwise require a complete refret if you remove too much material.

But, if you have the necessary tools and have a less valuable guitar to practice on, be sure to protect the guitar’s fretboard by masking or utilizing fret guards (which sit on top of the fret and protect the surrounding fretboard).

Then file the fret down to the same height. Once done, take a 3 corner file or dedicated crowning file and begin to crown the fret to reduce the surface area at the point of contact for the strings.

Once done polish the frets using 1200 grit sandpaper, followed by super-fine grade steel wool.


Summary

I hope the information above helps you identify and repair dead frets. As previously mentioned, due to sympathetic resonance in some cases fixing dead frets is difficult and some guitarists choose to live with the problem. However, in the majority of cases, a dead fret will be caused by a high fret which as shown above can easily be identified using a fret rocker. If you enjoyed this article be sure to check out my other articles on acoustic guitar maintenance.





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