The goal with our fretwork is to create a fretboard that is smooth and soft. As such, the fret ends are dressed in a spherical ball. As well, the frets need to be level.
This used to be done by leveling with a flat sanding block and using feeler gauges to measure the closeness to a flat, straight beam. This has problems because of buzzing caused by the neck tension. This problem has been improved by waiting until the tension is on the guitar and the slope from the neck being pulled up is in place.
A small flat sander is inserted under strings and sanded level, this is fast and makes it easy to remove any erroneous buzzing. The next thing done is polishing the frets using an orbital sander. This can be done by hand but an orbital sander at a low setting with a light touch will achieve the job just as well, with significantly less work.
There are three steps: A. dressing, B. leveling and C. polishing. This article and video will detail the process we use to do them.
The items needed:
- Sand paper—400 grit
- Right angle iron
- Double stick tape
- Strung Guitar with fretboard ready for work
- Diamond fret crown file
- Orbital sander
- Sanding and polishing pads from 400-12000 grit
- Furniture oil
- Paint scraper/razor blade
- File with edge shaved off.
First the special file is used to put an angle in the fret.
It is a simple tool, but the alteration is key.
We can take and file that is barbed on all sides and then take it to a sander and quickly grind down the edge.
Count the number of strokes given for the first fret and repeat it for all of them. Try to find a rhythm to help do this, repeat for both sides of all the fret ends.
Next A diamond file from Stewmac is taken and used to dress the fret ends further. The file is rolled over the end while filing. When this is done in a smooth manner a few times it creates the effect of a spherical ball. One of the keys is to listen to the sound, when there is a light amount of scratching that is even on both sides the job is done. It’s important to keep the file at the same angle while rotating around.
Next, we move on to leveling. The key tool in this process is an angle iron with a piece of sandpaper attached to it.
The angle iron is inserted under the first two strings and then run back and forth. The first fret is avoided because it sets the initial point that the slope of the frets starts from.
This is repeated going under all the strings. It is then done going back the other way for all frets. This step is done because the angle iron is not a perfect 90 degrees. Instead it slants one way so to make an even level it’s best to go back the other way to smooth out any bumps.
The sound cue in this case is the clack of the frets as the iron passes over it. Uneven frets will create more sound and clank compared to the smooth frets. There will always be a certain amount of sound so it’s the change that’s important to hear.
Each note is played on the fretboard to check the progress. When there is no buzzing it’s time to stop. There might be a particular note that is buzzing. This is where this process shines. The buzz can be eliminated at the spot by running the file back and forth over the area a few times, this evens out the high spots.
The frets are crowned by taking the diamond file and going over them many times until the flat edge of the top begins to disappear. All of the scratches are going the long way across the fretboard and we want them to move horizontally so there is no scratching when playing.
The last process is polishing the frets. An orbital sander is used with the polishing pads of various grit. The lowest is put onto the sander and turned on to a low setting. The sander is run back and over each fret at and angle.
The angle that works best is to be as close to the fret as possible with the pads edge hitting the fret in front. Each fret is sanded and then the process is repeated with the increasing grits.
After this the fretboard is wiped down with oil on a cloth and that’s it for our fretwork process.
Max Dickinson, the author, is a luthier at Portland Guitar, a boutique guitar shop. They offer innovative acoustic and acoustic-electric guitars. One such is a patented split saddle bridge, now for sale, an adjustable intonation bridge made from wood. Check out the bridge, guitar build progress, informational articles and more at the website and also on the Facebook page.