Leveling, Dressing and Polishing Frets: The Portland Guitar Way
The goal of Portland Guitar fretwork is to create a smooth and soft feeling for the acoustic guitar player, who interacts with the fretboard most of all. A good playing experience is one where there is no buzzing, and there are no hard edges for the hand to run into.
To achieve this goal our frets are dressed, leveled and polished using a few processes. These include dressing the fret ends in a spherical ball. Levelling the frets while the tension is on and polishing the frets using an orbital sander. This varies from other methods in a few ways.
The leveling can be done with a flat sanding block and using feeler gauges to measure the distance from a flat, straight beam. This has problems because of buzzing caused once the strings are brought to tension. This process 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 the strings and the sanded level. This is fast and makes it easy to remove any erroneous buzzing.
The orbital sander is used over sanding blocks because of speed and ease of use. It does not affect the quality, so this Is an easier way to do it.
This article and video will detail the steps we go through and the important details we watch for when performing each task. There are a few materials and tools to get together before beginning. These are listed below.
Right angle iron
Double stick tape
Strung Guitar with fretboard ready for work
Diamond fret crown file
Sanding and polishing pads from 400-12000 grit
Paint scraper/razor blade
File with edge shaved off
The following are the pictures of the tools and sandpapers that we used to do these tasks. There are a variety of tools here, some can be purchased at a hardware store such as the right angle iron, while others need to be purchased from a woodworking supply store or in particular cases a luthier supply store such as StewMac.
There are a few tools that require our creation. It is one of the great parts of woodworking to create your own tools and jigs. In guitar making there are many specialized tasks. In this case taking the fretboard from rough to finished. We must make tools for both dressing the frets and leveling the frets. These will be detailed in the pictures below. It is my belief these instructions can be followed. Please send me a message if there are additional steps needed to follow this guide.
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 a file that is barbed on all sides and then take it to a sander and quickly grind down the edge.
It doesn’t take much to grind all the barbs off the file. Make sure to wear proper protective equipment while doing this and keep your work area clean of sawdust.
The file is placed at a 45-degree angle to the fret and run back and forth. The key to doing this is consistency.
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, and repeat for both sides of all the fret ends.
Next a diamond file from StewMac is 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.
Once satisfied with the work, take a folded paper towel and run it up and down the sides of the fretboard making sure to catch it on each edge. If there are pieces of paper towel on the end of the frets, then it is too sharp and can be rounded off more. This is a simple test and gives a good measure of the progress made.
Next, we move on to levelling the frets. This could be argued as one of the most important parts of the guitar building process. A level fretboard is key to being able to build an acoustic or electric guitar. Fret buzz is caused by the frets being uneven. If one fret is higher than another than it will tap the high one while played and cause buzz. The way to get rid of this is to have a level fretboard.
The way we did this before our current procedure was by using a flat edge and sanding the frets until they were level with the edge. This has a problem, once the tension is put on, the neck will bend at an angle. This is counteracted by the truss rod but sometimes there is too much for it handle. The new method fixes this by sanding the frets after the strings are put on. This means that the neck bow is already in place when we start.
The key tool in this process is an angle iron with a piece of sandpaper attached to it. This is used to reach the frets underneath the strings. The next pictures will detail how this is made.
The pieces needed are turners’ tape, an angle iron and a piece of sandpaper. The sandpaper is attached to the angle iron using a piece of the double stick tape. Press it into place using a clamp to make sure it sticks. Another upgrade to make is to add a handle to the top to make it easier on the hand. This is done by gluing a dowel onto the side of the angle iron.
The guitar is placed on the bridge with the tension on. The sanding device 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. It is also hard to reach it given the tension of the strings.
The higher frets are preferentially sanded down while leaving the low ones untouched.
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.
To recognize when the frets are level listen for 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. This clacking can also be felt in the hand as it moves over the frets.
To check your progress, play each note on a string. If there is buzz then sand that string. Do this for all strings and when there is no buzzing it’s time to stop. A frequent situation that occurs is a particular fret buzzing in the middle of the fretboard. 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 is much more convenient than undoing the strings and then sanding the frets.
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. This puts many scratches going along the frets because that is the direction of motion for the file. If we keep this as is, when a player slides the string on the fret it will not be smooth. To remedy this, make successively smaller scratches going in a circular pattern over all the frets with an orbital sander.
The grits used are 240,600,100,2000,6000,12000. 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. More time needs to be spent with the lower grits than upper grits. The amount of scratches is most at the lowest levels.
The angle that works best is to be as close to the fret as possible with the pad’s edge hitting the fret in front. The sander doesn’t need to go over the top of the fret. It’s important to not change the level on the fret.
After this the fretboard is wiped down with oil on a cloth and that’s it for our fretwork process. The oil that we use is danish furniture oil. There are many that can be used, and we have no preference so far for one over the other. It doesn’t take much to cover the fretboard, so our bottle of danish oil has lasted a long time.
Careful attention needs to be payed to each step of these tasks. The sounds that are made are a key indicator of how much material is taken away and in what way. There are also other ways to gauge your progress such as light reflections. It is important to check your work as well. We try not to be satisfied until all the mistakes we can see and remove are gone.
Through performing each of these steps and paying careful attention to the frets while doing them the Portland Guitar fret process is complete. The result is a fretboard that is level to the point of no buzzing on the fretboard at the lowest possible action. In addition, the appearance of the fretboard is unmatched. The fret ends are a beautiful ball with no edges and the frets themselves are sparkling polished. These provide the owner of the guitar with a pleasant and smooth experience while playing.