When the neck of a guitar (or bass or mandolin, etc) is evaluated for setup, measurements are usually in thousands of an inch. Three thousandths is notated as .003-inch. The average U.S. bill currency is .004-inch thick. Trained fingers can tell a difference of less than .001-inch.
The final slot depths are somewhat a matter of taste on the part of the player, and a matter of skill on the part of the guitar tech. A tiny fraction of an inch deeper or shallower can make a big difference in action, especially in the first five frets or so. A slightly higher slot yields a more lively action in this area of the neck.
Making a new nut for a guitar requires a series of detailed, painstaking steps. The next part of this process is where the rubber meets the road. Slot filing may be the most important aspect of nut making. Even a rough-cut nut -- with gaps between the nut and its slot and ends that overhang the shelf -- could be properly filed to play well.
I’ve got my new bone nut fitting well in the nut slot. The ends have been trimmed down a bit, leaving about 1/16-inch overhang on either side. It is a good idea to creep toward the destination rather than cut the nut to the exact width of the slot. If you do that, there is no length left for filing and polishing without coming up short.
Our next move is making a nut for this guitar. This component is one of the most important found on any guitar. No matter how beautiful your fret work is, the nut will make or break your guitar. Many people take a nice nut for granted. That’s because a guitar won’t work right without one. Even the cheapest production guitars are usually sold with a functional nut.
When I left off, I had just finished pressing 22 stainless steel frets into the maple fingerboard of an ’83 Squire Telecaster. The next job is to file down the fret ends. They are sharp now and easier to work on after this step. Using a smooth-cut file, I ride down the little tabs of the frets along each edge of the fretboard. Don’t over-do it. Make passes in the “cut direction” of the file until the edges of the fingerboard feel smooth.
OK, we’re back and ready to begin. Last week I sanded the lacquer finish off of most of the neck and prepped the fingerboard to receive new fret wire. I used a radius block to sand the fingerboard and maintain its 7.25-inch radius, and ran the grits from 180 to 600. Since this neck is going to be oil finished, I wanted it to feel as silky and smooth as possible.
All of the original frets have been removed from the neck I’m working on. At my recommendation, the owner of the guitar has agreed to go naked. The neck and fingerboard of this Tele are covered in gloss lacquer. It’s not thick. Not so thick as to conceivably choke much tone. In my experience, though, lacquer on the neck and fingerboard means a guitar that is just a little bit harder to play. And not in a good way.