Repairing and Replacing Frets on Guitars

Fret wire comes in a variety of sizes.
While it is essential to choose wire with the appropriate fret tang width for proper fret slot compression,
 players can choose from a variety of fret crown widths and heights.

First let me start by clarifying a few terms:

Compression Fitting My preferred method of refretting is commonly referred to as the 'compression method'. Installation of the fret wire is done by pressing the fret into the fingerboard. Generally the fret's "tang" (the portion which is pressed into the fingerboard), matches the fingerboard slot and it's tiny barbed teeth provide the grip necessary to hold it securely in place. This is the way most factories do it.

Epoxy and frets For obvious reasons, installing frets by pressing them in is greatly preferred. However, on occasion I see fingerboards that have already had their frets glued in with epoxy.
This method of refretting was once more widely used but later discarded by many repair shops as it alters the original fingerboard slots. The fret slots were cut larger so that the fret tang could drop into the fingerboard slot without a great deal of effort and epoxy was used to hold the fret in place. Unfortunately this method can leave the fret slot so large that fret wire with a large enough tang to compress that slot often does not exist. In cases where the instrument has already been fretted by this method it may be necessary to refret it using the same method. Unfortunately, the damage has been done and your other alternatives are to replace the fingerboard.

VIEW PICTURES OF REFRETS

Special Considerations When Refretting Instruments

*Necks without adjustable truss rods It is extremely important that a snug fit is achieved when installing frets for obvious reasons, but there's even more issues to consider if your instrument does not have an adjustable truss rod (mid '80's & earlier Martin's for example)...

When tension is placed on the neck it is normal to see some amount of relief or bow. When the relief becomes excessive we normally tighten the truss rod to counteract it, but alas, we are not as fortunate on instruments without adjustable truss rods. Most instruments built after the turn of the century do indeed have a truss rod, however, like earlier Martin's it may be an inlayed square or T bar rod which is neither visible nor adjustable.
When performing a refret on a neck such as this it is often helpful to use frets with large fret tangs to create a wedge effect when pressing them into the fret slots. If the fret tang being installed is larger than the fret slot in the fingerboard, the compression can help to stiffen and slightly straighten the neck. In cases where the bow is excessive, fingerboard planeing will most likely be necessary as well.
Adversely, if one were to perform a refret on a neck such as this and use a smaller fret tang, the resulting gaps between fingerboard and fret tang would further weaken the stiffness of the neck and could result in even more relief.
Necks with excessive relief (forward bow) are often referred to as banana necks and increase the instruments overall action (distance between the strings and frets) making it more difficult to play.
 

*Stiff Necks / Necks with No Relief  When refretting very stiff necks or those that manage to remain quite straight (flat) when strung to pitch an improper refret can cause an enormous problem. After reading the section above you can begin to understand the role which the frets tang can play on neck straightening. While this is extremely useful on necks with too much relief, refretting a straight, non-adjustable or very stiff neck in this manner can render the neck backbowed.

Binding Nubs

*Bound Fingerboards with binding "nubs"- If you look closely at the frets on a bound Les Paul you may notice the small "nubs" of binding present at the outer edges of the frets. When these instruments were made the board was fretted, the frets where filed even with the board and then the binding was attached. The binding was then scraped level with the fingerboard leaving the small nub of binding at the end of each fret. Many like the feature as it prevents strings from catching under the ends of the frets when the are rolled off the edge of the fingerboards (which can certainly be prevented without them BTW).
However, when refretting an instrument bound in this manner, those nubs are completely sanded away when the fingerboard is resurfaced in preparation for new frets. If a partial refret is to be performed on this type of neck the nubs are usually preserved or recreated. You can view an example of a partial refret on a bound board with binding nubs on the Mandolin refret page here.

*Maple fingerboards Painted, maple fingerboards pose a different challenge. Many manufacturers apply top coats of clear lacquer to the fingerboard and frets after the frets have been installed, effectively "sealing" the frets under lacquer. You'll find this on most Fender maple neck guitars. When it's time to refret, the finish must be meticulously scored to prevent serious finish chipping and loss when the frets are removed, another time consuming effort necessary for a professional looking repair. Once the frets are removed, I lightly scuff the original fingerboard finish to clear away burrs and other inconsistencies that would prevent the new frets from seating correctly. Then the frets are installed, leveled and a new top coat of nitrocellulose lacquer is applied to seal the frets and create an original appearance. Finish is removed from the crowns of the frets when the frets are leveled.

*Bar Frets - These solid, uniformly shaped frets were common place on instruments before the turn of the century though you will see them on Martins as late as the 30's. Since bar fret wire has a tang much larger than traditional fret wire we are faced with using the same wire when refretting is necessary or making changes to the fingerboard to accommodate the smaller tang of the standard crowned wire of today. Bar frets require a good bit more time and experience than traditional fret work and therefore are a bit more expensive to refret.
 

Fret Leveling
 (a.k.a. Fret Mill, Level and Dress, L&D, Fret Planeing)

Fret leveling is performed for several reasons.

How is it done?   To put it very simply...when performing a fret leveling on a guitar, bass, mandolin or other fretted instrument the frets are filed as a whole using a perfectly flat file (stone, bar etc.)  which gives the frets a consistent height. Attempting to file frets individually will leave you with a roller coaster and no way to gauge your progress. Any loose or sprung frets must be corrected first. Once the tops of the frets are on a level plane with one another the crown is shaped.
Fret crowning is necessary not only to round the fret over for comfortable playing but also to insure the position at which the string contacts the fret is dead center. Crowning a fret simply refers to putting the smooth, rounded surface back on the top of the fret. This insures that the string contacts the frets center when fretted. The scratches created by filing and crowning are then sanded and polished out. A simple fret polishing can have a profound effect on how the strings feel when bending.

How low can ya go when leveling frets ?? Fret height is of course a big factor when considering fret leveling and there is a limit to how short a fret can be and still do it's job. Very short frets (say under .025 tall) can create a buzzing problem for some players, especially when the fret crown width is small. The strings need to break down and over the fret to sound clear and a very low fret often dictates the use of more pressure to obtain a clear note.
Grooves worn in the tops of frets by string wear can sometimes be removed by leveling, but, that will also depend on the present height of the fret as well as the depth of the groove.
 

What are the symptoms of a high fret??  Let's say you are playing a note on the 5th fret and a noticeable buzz is heard, but, after moving up a fret the buzzing disappears.
Buzzing that occurs in one central position may be an indication of a sprung (loose) fret, frets which are not level with one another, or a hump in the fingerboard which rises the height of the frets.
 

On flat top acoustic guitars you may occasionally see a hump in the fingerboard where it joins the body. When this hump is caused by a dried out top which has flattened, obviously that issue needs to be addressed first. But it is sometimes necessary to level the frets in this area in order to play up the neck cleanly.
On many archtop guitars the end of the fingerboard is somewhat suspended over the body and is not glued directly to the top like the fingerboard on a flat top guitar. As a result this "suspended" fingerboard extension can take a somewhat upward curl over time and create what I call the "ski ramp". This condition causes the last frets on the fingerboard to be higher than the rest giving you a very Sitar-ish sound when playing up the neck. When the strings rest against the frets in areas it is often referred to as "fretting out".