How to replace the nut on an acoustic guitar or classical guitar
Replacing the nut (and saddle) on your guitar is an easy and affordable way to improve the tone quality of your guitar. Like upgrading the RAM on your computer, the performance enhancement per $ dollar is the greatest because bone nut is cheap yet the improvement is tremendous.
It is this white piece on your guitar that holds the individual strings in place along the guitar neck.
When do you replace the nut on your guitar?
1. When the nut has been worn out due to age or wear and tear. The tension of steel strings will cut into the nut over time, causing intonation problems (inaccurate sounding notes along your fretboard), causing fret buzz or affect the overall tone quality of your guitar. In severe cases, the nut may even crack and break into pieces.
2. Most guitars, with the exception of the very higher end guitars that cost thousands of dollars, come with a default nut made from plastic. You can easily enhance the tone quality of your guitar by replacing this plastic nut with an affordable one made from animal bone (like ox) or the more expensive FMI (Fossil Mammoth Ivory). Both types of nut will enhance the tone of your guitar over the cheap plastic types because of its superior vibration or sound conducting properties.
Nuts are usually secured to your guitar neck with a tiny bit of adhesive glue as the tension of the steel strings will hold the nut in place. The nut is unlikely to shift much because this tension is sufficient to keep it in place for a long time.
To remove this nut, remove or loosen all the guitar strings. Then tap it very lightly with a soft mallet from either side to dislodge it. You will find that it comes off rather easily.
How to place in the new nut?
Start by placing the new nut on the guitar neck indent to ensure that the nut is of the right width for your guitar neck. If it is too wide or narrow, you may need to get another nut that matches your guitar neck specifications.
If the nut is too thick for the slot, some tiny adjustments can be made to let the nut sit into the slot perfectly by sanding it with fine sandpaper or a knife sharpening stone. Be sure to file it down to size in a consistent manner so that you do not alter the shape of the nut. Do it with patience and make sure you check every now and then to see if the filing is enough. Try not to over-file such that the nut becomes too small for the slot. You would want a fit as close to perfect as possible.
Once you have determined that the nut is of the right size and it can sit snugly on the slot of the guitar neck, apply a thin layer of glue - craft glue or super glue - on the slot. Make sure it is very minimal, just enough to hold the nut in place while you restring the guitar. The tension on the strings will help to hold the nut in place once your guitar is restrung. Go easy on the glue, otherwise you will have difficulty removing the nut in future, if you need to replace it.
Finally when the nut is sitting properly on the guitar neck, you can start to restring your guitar.
Enjoy the new improved sound of your guitar!
For further improvement to the sound, you can consider changing the saddle and bridge pins to bone material as well!
Affordable bone nut is available here.
Would it help to lower action if I file the nut lower?
Some tutorials recommend filing the nut to a lower height if the action on your guitar is too high. Action refers to the distance between the strings and the fretboard - a higher action means a larger gap and more pressure is needed to press down on your strings to fret a note. Many people prefer a lower action as it is easier to play.
Personally I do not recommend filing the nut to lower action as there are other factors that cause the action to be high. Firstly, check the straightness of the guitar neck to ensure that the action is not due to a warped neck. Then, I will file the saddle instead to lower the action. You can also consider changing your strings to a light gauge (i.e. thinner strings) to loosen the tension.
You only need to file the nut if after checking the neck and lowering the saddle height, you still have difficulty fretting the first fret. That is, despite using great effort, you are still unable to fret the 6th E string down such that it touches the first fret properly. Then you can try to file down the nut in a small increment way.
Take note that over doing it can cause fret buzz along some of the frets.
Lowering the action is a delicate task that requires patience, experience, some trade-offs and lots of trial and error to find the perfect balance between low action and no fret buzz. The nut, guitar neck, frets and down to the saddle all can and will contribute to fret buzz.
