When is it necessary to level frets on an electric guitar? What are signs that frets need leveling? What are signs that frets need to be replaced?
When steel strings come in constant contact with softer nickel frets, eventually the steel strings take their toll. Over time, depending on how often you play, how heavy handed your fretting technique is and how much bending you do, your frets will begin to exhibit signs of wear as you have probably already discovered.
Two common signs that your frets may need attention are gouges or divots directly under the string, and flat worn areas on the frets that may cover as much as half the fret.
The gouges typically occur under the steel strings and most often on the frets near the headstock where open chords are often played. Flat worn areas more commonly occur in the higher fret positions under steel strings where a great deal of string bending may occur.
At some point these flattened areas or gouges will begin to have a noticeable effect on your intonation and/or contribute to fret buzz. When this happens it's time to take your axe to a qualified guitar tech or luthier who has the correct tools and experience to "level" and crown the frets.
During leveling, the technician will basically file down the frets, re-crown them and polish them to take out the divots or the flat areas. If the frets have not worn too much or the divots are not too deep, this can be done successfully - perhaps several times before a total or partial re-fret is necessary.
At some point there may not be enough fret height left to get good results from leveling or the gouges may be too deep. In this case either a partial or total re-fret will be indicated. A partial re-fret can be done if only certain frets near the headstock are in too bad of a shape to level. But often a partial re-fret is almost as much work as a total re-fret. That is because whenever you replace some frets, all the frets will need to be leveled to the least common denominator so that you don't have some higher than the others. So instead of leveling brand new frets, it's usually better just to do a total refret.
If you are like me and tend to wear out your frets faster than most folks, you might consider paying a little extra to get case hardened stainless steel frets instead of nickel frets when it comes time to re-fret a guitar you plan to keep. Luthiers don't like steel frets as well because they are much rougher on their fret files and take longer to crown. But you will go a longer time between re-frets if you replace your nickel frets with steel frets.
If you wear your frets too low before refretting, besides getting fret buzz and inaccurate intonation, you may eventually start damaging the fingerboard when bending strings and scraping them against the wood.
You would be surprised how effective leveling and crowning can be. I have had very deep visible divots taken out of some of my guitars with just leveling. I have only had one guitar re-fretted. Next time I re-fret, I will be using steel frets.
When a guitar is built in the factory, after they install the frets into the fretboard, they should level them before the assembly is complete and the guitar is sent to the store to be sold. But sometimes a guitar with un-level frets might sneak through quality control.
If you buy a new guitar and you immediately notice that the action is uneven on different frets, take it to a guitar technician for a setup, and indicate that you'd like them to check whether or not the frets need leveling. They can level the frets as part of the setup procedure (which also adjusts many other parts of the guitar in order to make it easier to play and to improve the intonation).
On older guitars that have been played a lot, frets wear out in certain positions on certain strings depending on how you have played it. Certain notes will buzz because the fret material has worn out under that position. In this case it may be possible to re-level the frets and do another setup to adjust the truss rod, nut and bridge so that the guitar is restored to buzz-free playability.
But if the frets get extremely worn after years of playing, the frets may need to be replaced.