Sunday, February 8, 2009

Making a nut for playing slide guitar

I recently mentioned to a friend of mine that I was thinking of making a new nut for my acoustic guitar, and he generously donated a couple of nut blanks. One is ebony and the other is Corian. I will use the ebony one to make the new standard nut (which will no doubt be covered in a future blog entry), but decided to make a raised nut with the Corian for when I want to play slide guitar.

Corian, incidentally, is a material that is most commonly used on the surfaces of kitchen units, but has also been used by both Gibson and Martin to make nuts. It is not the best material, tonally-speaking (though it’s hardly crap), but it is easy to work with. More info about Corian can be found here:

One of the bonuses of a raised nut for playing slide guitar is that it will be flat, rather than radiused, so no need to work out exact curvature, etc., and since it will be raised off the fretboard, there is no need to worry about precise height measurements. That coupled with the fact that it is Corian should make this a pretty easy project.

My guitar neck is pretty thin (just how I like it). It measures a little under an inch and three quarters. One and eleven sixteenths would probably be more accurate. The nut for playing slide was going to be cut a little wider – something like one and seven eighths. It would stick out a little on each side, but this is OK.

First thing was to cut it roughly to shape. It was just a little too thick, but I would deal with that later. As for the length, well, I had to cut about three eighths of an inch off with a hacksaw. I didn’t feel the need to take a photo of this. Next was to file a curve onto the top, so that the strings fall away on the head side of the nut. Unfortunately my vice isn’t the best, so I needed to do the filing in the way that is pictured here, one half at a time. This method puts the nut at risk when you lean on it with the file, as it could easily snap in half, so be very careful if you do it this way, and support the back of the nut with your finger. If you have a better vice that can grip the full length of the nut while you work on it, then that’s a better solution.

As previously mentioned, the nut was just a little bit too thick, so I solved this by rubbing it on a piece of sandpaper, which was lying on a flat tile. This is a commonly-used and very effective solution. I also used the sandpaper to help finish rounding off the top curve a little bit too.

Here's the basic shape after the vice and sandpaper:

Next thing was to file the nut slots. This can be quite intimidating, but the secret is a good set of nut files and a bit of reading (of course practice makes perfect too). I highly recommend checking out for information on this type of thing.

I recently bought a set of nut files called “Norman Guitar Nut File System”. They’re made by a guy called Norman Trent and he mostly sells them on ebay. He has excellent feedback, but some Googling suggests that some people are not happy with how long the files stay sharp, or Norman’s customer support. All I can say is that I got my files pretty quick and they worked well on this project. Norman also supplies a handy laminated sheet to help you mark the correct position for the slots, as shown here.

Slot positions marked and ready to do some filing.

The next step was to actually cut the slots. The depth you cut down should be a little over half of the diameter of the string itself. Also, you should file down at an angle so that the slot follows the curve of the top of the nut. This is to make sure the string makes good contact at the very edge of the nut when it meets the fret board and therefore cut out any buzzing, or intonation problems.

After the final filing I gave the whole nut a once-over with very thin sandpaper, just to shine it up a bit. Here is the end result.

And now here’s the nut on the guitar. It sticks out a little bit at the sides, as planned, and also sits pretty high off the guitar. Now I can really attack that thing with a slide without worrying about banging into the frets.

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