What is Fret Sprout?
It's a common problem, and you should fix it.
By Jeff Owens
Fret sprout: an undesirable condition in which the ends of the frets protrude from the edges of the fingerboard.
Run your thumb and fingers along the sides of the fingerboard of your guitar or bass; along the top edges of the neck. The sides of the fingerboard should feel smooth and uninterrupted. While you likely will feel the ends of the frets, you shouldn’t feel them sticking out from either edge of the fingerboard. If you do, congratulations—you’ve got fret sprout. Happens to fretted instruments of all kinds regardless of how expensive they are.
A mild case of fret sprout might be noticeable without being especially annoying, and it wouldn’t necessarily keep you from playing the instrument. That part is up to you, although there are plenty of players for whom even slight fret sprout drives them nuts. A pronounced case of fret sprout is a different story, though—pretty uncomfortable, and a maintenance issue that requires attention and repair before the instrument is really considered useable.
If your guitar or bass has fret sprout, it probably didn’t leave the factory that way. Rather, the problem likely developed later on—perhaps during shipping, storage or retail display—when the usual culprit, low humidity, caused the fingerboard to contract.
Frets are made of unyielding metal—fret wire, so it’s not like they somehow become longer. Fingerboards, on the other hand, are made of wood, and wood is a once-living material that definitely yields to the vagaries of climate and other environmental conditions.
When dehydrated, a fingerboard can actually narrow, leaving the fret ends protruding slightly from either side. It’s especially common in hot, dry climates and in regions with harsh winters where people run their heating systems pretty hard. This lowers ambient moisture, which makes wood shrink, which produces fret sprout. For an instrument you truly care about, in fact, fret sprout is one of the reasons why you should keep it within a specific temperature and humidity range (the general rule is that your guitar is comfortable in the same climate range that you’re comfortable in).
Fortunately, the very nature of fret sprout makes it extremely easy to detect, even by novices (use the test described above), and it’s usually easy to repair. You will, however, need somebody qualified to do the work, unless you happen to have a specialized fret beveling file in your tool box and you’ve done this sort of thing before. Assuming (one) that you don’t and (two) that you haven’t, a fret beveling file is a special block-shaped tool that luthiers, techs and other service personnel use to file the fret ends uniformly flush with the edges of the fingerboard (usually beveled at or around a 35º angle). They then “dress” the fret ends using other specialized files, and polish them for smoothly level and uniform feel and a clean, professional look. The whole process is kind of like a manicure for the frets, and every bit worth it.