Recognizing Excellent Fretwork

Fret jobs are truly the grunt work for luthiers and repairmen. They entail a lot of work, and the quality of that work varies greatly. Below, Guitarsmith Richard Stanley is reknowned for his fret work, and here he discusses his process for doing a proper fret job.

The size of the fret

Stanley: I still run into many players who think they have to replace their frets with the same kind of fret wire they're replacing. But fret wire is like guitar picks. Nobody should tell you what to use. Figure out what best suits you. The only thing I try to do is steer players away from are any fret wires with less than a 0.040" high crown. Anything less allows for only or two facings at the most. From my own clients and personal experience I feel that a fret that is 0.035" high or lower is unplayable. 

Unfortunately, an awful lot of instruments (especially acoustic guitars) get shipped with undersized fret wire. When players complain about playability, almost all of them think that it doesn't play well because the strings are too high. More of the time, it's because the frets are too low. When frets are too low, particularly on a steel stringed instrument, your fingers are into the fingerboard before you can close the string adequately to the fret. Also, bending is more difficult on low frets. This is why I end up re-fretting a certain number of new guitars every year. Players recognize it. A lot of them will try to use the original frets as long as they can, and then up the fret wire size when they replace them.

How the fret is mounted in the fingerboard

Stanley: Often overlooked is the need to at least trim, if not re-cut the fingerboard before you put in the new frets. Doing first-time re-frets reveals that many instruments have irregularities in the board such as bumps, dips, or too much residual warp. The fingerboard must be true along its length and well faired or even across the radius before you re-fret. Because if these irregularities are not corrected in the fingerboard surface beforehand, you must compensate for them later in fret leveling operation. That results in frets of inconsistent size and shape.

Then, to get a fret slot that's appropriately sized for the fret, you need to custom fit them. For example if you're putting in a bigger fret than the original, you have to adjust the slot. It is possible to force the neck into a reverse warp if you set frets too tightly in the board.

I set frets looser than most people do, and I've been setting frets this way for a few decades. I set them in a wider slot so that they don't have to be hammered in, but rather tapped-in lightly and bedded in epoxy.

A lot of people don't glue at all, and the ones who use CA (super glue) don't usually glue the whole thing. They do spot, spot, spot the ends and the middle. I use 5 minute epoxy because it has better gap-filling properties than CA glue. And the epoxy is tougher and more resilient. CA glue cures out more brittle which works great for fixing chips in the finish. But it's not good for setting frets because it doesn't give at all. (Qther people) set with CA glue because you can frequently pull them without heating them. 

Epoxy maintains its character over a wide range of temperature up to something like 130° Fahrenheit or so. They literally won't move with epoxy. If you try to pull them out without heating them, you'll tear up the board. I just recently saw two boards I had re-fretted over 20 years ago, and not one fret on either board had moved not a bit! Whereas if you don't glue frets down, three months later, when the first seasonal change hits, the leveling job will be upset. You go through a wet season, the wood expands. In the next dry season, the wood contracts leaving the frets loose. Frets that appear well set may be loose enough to diminish sustain and tone. A fret can appear to be tight, and have a perfect finish on it, but can even produce a fuzzy buzzing noise almost like common fret noise and it will cut into sustain.

How well the fret is finished

Stanley: After setting the fret, I cut off the excess fret from the ends and I bevel them with a relatively coarse file at the edge of the board. You shape the end of the fret to blend into the fingerboard so that it's nice and smooth against the player's hand as they slide it up and down the board. I think everyone has owned a guitar with fret edges that could make you bleed. No good!

The next step is to level the frets. Fret wire specs vary some manufacturers quote as much +/- 0.005" and that means the crown heights might be off that much even if they're all set perfectly. So, using a relatively coarse file, you go over them, and knock down the high frets. Hopefully there won’t be one fret that's lower than all the rest and then have to bring down all the others. After leveling, the frets with flattened tops. So then you have to go over them with a dedicated fret file.

Next you re-crown the fret by filing it. Get it back to a uniform shape, and get rid of the hard edges. The crown (all you see when the fret is mounted) of typical fret wire is roughly hemispherical in shape usually about twice as wide as it is high. Re-crowning and polishing is the most time consuming part of refretting, but if the frets seat uniformly, less work is required at this stage. Even more work is required to properly shape and finish the ends. It's more than half the whole job doing the ends the first time. It takes a lot of filing with several different types of files. This is why of all the things about fret jobs you just never see the ends done well.

Once the crowning and ends are done I use sandpaper, starting with a 320 grit silicon carbide paper, and moving on to 400, 500, 600, etc. I also use some 3M micro grade papers up to 8000 grit (one micron grit size!) for finer polishing work. The frets look great when they're done. You can see your face in them when you get close, but it's not for appearance. When a fret is in good playing shape, that's just what it looks like. They sparkle.

I can get four re-surfacing jobs out of medium size frets, but if they are re-leveled carelessly, removing more of the fret crown than necessary, it is possible to waste a set of frets in just one facing session. None of the mass producers, or even individual builders put the time in to really finish frets well.