Guitar Nut Replacement
Replacement of a Guitar Nut is Usually the Result of
Over-Aggressive Filing of the Nut
The Guitar Nut is the small piece of plastic, bone or ivory that separated the fingerboard from the head piece of the guitar. Often due to wear or over-aggressive filing to lower strings, you may have to perform a guitar nut replacement.
Tools Needed For This Repair:
Tools To Made The Job Easier But Not Necessary
If you are getting a lot of buzzing with your open strings when you are not strumming the guitar too hard, it is likely that you will be needing a guitar nut replacement. Don't consider slipping a piece of wood veneer or worse yet several pieces of paper beneath the nut to bring up the level of the nut grooves.
Another common reason that nuts need replacement is after a refret job is preformed. The strings were seated in the nut lower and there was not any buzzing on the frets because they were worn. With new frets installed, the top level of the new frets will extend too close to the string action of the old nut grooves.
Analyze The Old Guitar Nut First
Make sure you have access to a solid work bench or work surface of the proper height. For shorter people this will be 32" to 34" and for taller people, 36" is standard.
Place a padded surface down on the work bench that is soft and free of any debris, such as wood chips, metal shaving or any other foreign objects. I prefer to use an old Rug or something like that.
Have access to a very good lighting source that is adjustable and you can aim it at your work.
First thing in Nut Replacement is analysis of the old nut. Is it set into the fingerboard or between the fingerboard and the headstock veneer? It is usually the latter. The nut is commonly held in place with a drop or two of white or Titebond glue and comes out rather easily with a sharp tap.
If the nut has been finished over with clear varnish or lacquer, it will be required to take a very sharp marking knife or xacto knife and trace around the nut where it joins the neck and headstock. Make sure you cut complete through the finish so the nut will not pull any finish with it.
Take a small block of hardwood about 3/4" x 3/4" x 2 1/2" and place it tight against the nut, resting on the fingerboard. While holding this block of wood, give it a sharp tap with a Plastic-tipped Hammer and it should pop right off.
If the nut is set in a channel, it will take a great deal more patience for its removal. I usually perform the scoring operation above and then take a specially ground pair of side nippers and pull on the nut from above.
Also you can VERY carefully tap the nut forward, being careful not to tip if buy only just enough to loosen the glue - say 1/16" or so. You can also fashion a small fixture to tap it from the end, by securing the neck from movement - use some folded thick pile carpet to protect the neck and secure it with clamps or a vice.
If all else fails you can take a very Thin Kerfed Back Saw and carefully cut alone each face of the nut, being careful not to cut deeper than the original nut channel.
After the nut is remove, you will want to keep it as a pattern for your new nut, so do not throw it away!
Your next decision is the nut material you are to use for the replacement nut.
- Plastic: Forget it. Plastic is an insulator and it
insulates sound. Corian is often used on some factory guitars and would
be ok to use on cheaper guitars. I have a supply of scrap white corian
that I picked up from my local building supply center for these
- Tusq: nuts and saddles is a man-made ivory that is used by
many of the
factory guitars such as Martin, Taylor and Gibson. They are quite good,
but still not as good as bone or ivory. Your decision here depends on
the quality of the instruments.
Bone: Bone is a very good material to use for nuts and
bone is bleached and is very white, hard and dense. If transfers the
sound very well from the strings to the tone producing elements of the
guitar. Ideally used for high-end guitars, handmade guitars and
classical guitar. The black should be an Oversized Bone Nut Blank.
- Ivory: The premier guitar nut replacement material. No longer
available on the
free market, there are sources where you can get recycled ivory. This
should only be used on special occasions, such as replacing and
existing ivory nut on a very expensive classical guitar.
Ebony: There are some luthier's that use ebony on their
wouldn't recommend it thought.
After the nut is removed from the channel, it is time to clean out the channel of all glue and debris. If the nut channel was prepared properly, you will only need to remove some glue from the end grain of the fingerboard and possibly the nut channel itself.
Do this with a very sharp (I mean really sharp) 1/8" Chisel - preferably a instrument makers chisel. Work out the material slowly and do not enlarge the channel.
Prepare the nut width carefully sanding the nut on a sanding block made from 120 grit sandpaper adhered to a piece of flat marble or other dense-flat heavy material. Use a light touch and remove only a little at a time, constantly measuring with a calipers and comparing to the original.
When you get close to the correct width, check it against the actual channel.
Once you have the nut fitting snuggly in the channel, you have to trace the outline of the fingerboard onto the back side of the nut.
You should compensate for the height of the frets while doing this, so make your pencil mark a fret height above the fingerboard - or what I do, is during the shaping operation, I mill the top of the nut to with 1/16" + of that line. Be sure to trace around the ends of the nut too.
To mill the nut to size you should have access to a small stationary belt sander, disk sander or do it the old fashioned way with a coarse bastard file, with the nut clamped in a vice. Get the nut milled closely to the edge line and the 1/16"+ on the top. Always check on your progress often to avoid taking off too much material. It is better to have the nut a bit too high and shave it down slightly.
Our goal here is to have the three lowest string seated about 1/2 of their depth into the top of the nut.
Final shaping of the guitar nut replacement should be done carefully, while constantly checking against the original nut. I prefer to do final shaping with homemade sanding sticks. See my article on these handmade tools. Carefully smooth the nut and leave all but the final shaping to the last.
Now lightly glue the nut in place temporally. locate the two outside string location and strike a mark with a very sharp pencil and a straight edge.
Now carefully measure between the two marks with a vernier caliper or a machinists ruler or a mm ruler. Divide this measurement by five and that is your distance between each string. Carefully strike a mark at each of these locations
Now it is time to beg, borrow, steal or buy a set of Gauged Nut Files. These files are special files that will match the gages of your strings. Do not use a triangular file as you will just ruin all of your work.
Some do-it-yourselfers have used feeler gages that they filed teeth on the bottom. This will do in a pinch, but make sure you round the bottom of the gage plates first, as you do not want a flat-bottomed string slot.
Another option can ge a set of Torch Tip Cleaning Files. These are a bit hard to work with but they are gauged and round and will do in a pinch, plus you can buy them really cheap.
Carefully Shape String Grooves To String Gage
This is the tricky part of guitar nut replacement. You want the backside of the string slot on the nut (by the fingerboard) to line up with the marks. You want to angle the slot you file in the nut towards the proper tuner post to minimize binding in the nut.
Very important here - only cut enough of a channel to allow the string to set in the nut to allow you to string up the guitar.
String up the guitar and make adjustments to slots to get the strings down to a playable height. Follow my guide to adjusting your string action for this as it is a fussy operation in and of itself.
Now remove the nut and mill down the top until you have left about 1/2 the string diameter or less of the slots left. Also at this time, final shape and fit the nut. Sand the nut with 400 grit sandpaper and preferably buff it on a stationary buffing wheel if you have one.
Put a couple of drops of Tight bond glue to hold the nut in place and let dry and your Guitar Nut Replacement is complete. String the guitar up and enjoy!