from Experimental Musical Instruments
The fret wire we sell is hard nickel-silver wire. This is the material most often used in fretted instruments. (The actual composition is primarily of copper and nickel, with small amounts of other metals. Softer wires are sometimes used, but they tend to wear faster.)
We sell three sizes:
Large (crown width .114″, crown height: .051″). Suitable for anything bigger than a guitar, and sometimes used in large guitars as well.
Medium (crown width: .080″, crown height: .043″). Suitable for instruments comparable to or slightly smaller than a guitar or banjo.
Small (crown width .053″, crown height: .037″). Suitable for small instruments such as mandolin or ukulele.
Fret wire is installed by cutting a slot in the fingerboard and tapping the lower part of the fret wire (called the tang) into the slot. The barbs on the tang bite into the wood to hold the fret in place. It is important that the slot be the right width to hold the fret. If the slot is too wide, the fret will may sooner or later pop out. This fret wire requires a slot of .023″. This is a standard size; most but not all fret wires are made for this slot size or very close. You should cut the slot with a saw that produces a cut, or kerf, of this width. Most conventional saws produce a considerably wider kerf. It is recommended that you use a saw designed as a fret-slotting saw which will dependably produce a kerf of this width. Experimental Musical Instruments sells an excellent .023″ fret-slotting saw.
If you don’t have such a saw and you’re determined to proceed without one, you can look for a coping saw blade of this width or close to it. But be warned: Being less rigid and harder to control, the coping saw will be harder to use and won’t do as good a job as a fret-slotting saw, making it more likely that you’ll end up with loose frets.
Individual frets can be cut from a length of fret wire with wire cutters.
Tap the fret in place gently but firmly with a rubber or plastic mallet that won’t dent the wire. Clean up the edges of the newly installed frets with a fine file, being careful not to stroke in an upward direction which might loosen the fret. Be sure to remove any overhang, slightly rounding and smoothing the ends of the frets.
In the fret spacing for the standard western chromatic scale, the frets should be located such that each successive fret shortens the active string length to .9428 of the length for the previous fret. However, actual results don’t match this mathematical ideal because the slight stretching of the string when it’s pressed down behind the fret sharpens the resulting pitch slightly. You can compensate for this discrepancy by basing your calculations on a fictitious string length that is slightly shorter than the actual length. How much shorter depends on the height of the instrument’s action (how high the strings are above the fret board) and other factors, but a fictional length that is .994 times the actual length will often yield good results. If the action is unusually high try a factor with more compensation, like.992. For more information, look to the Fret Calculator in the tools section of the Experimental Musical Instruments web site. You can use the calculator there to determine your fret spacings, with or without built-in stretch compensation. The calculator can handle non-standard scales as well as the standard western scale.
Experimental Musical Instruments ● windworld.com
PO Box 421, Pt Reyes Station CA 94956 ● 415 663-9691 ● firstname.lastname@example.org