Defretting a bass guitar – Strange Guitarworks

I’ve been playing bass guitar for 29 years and I’ve been a fretless player almost all of the time. I lost my bass for the first time in 1998 after playing for only five years. I still remember this ordeal well: I ripped the frets out of my Peavey B-Quad, filled the slits with bondo, sanded it smooth, and finished work. It was pretty ugly and gross, but I thought it was functional at the time and introduced myself to the fretless life. Since then, my defretting technique has improved a lot (and I’d like to believe my intonation has gotten a little better too). I was recently asked to disarm a Fender Jazz Bass, and I thought I would take the time to explain my current defrosting technique.

The Fender Jazz-Bass is a kind of de facto fretless machine thanks to Jaco’s external influence (although I myself have a preference for Mick Karn). The frets of this particular jazz bass were grody to the extreme, just begging to be pulled out:

The trick in removing frets is to minimize damage to the fretboard. Fingerboards are prone to chipping when frets are removed and repairing is time-consuming. Hence, it is of the utmost importance to prevent this in the first phase. Usually I’ll over-tighten the truss rod, forcing the neck into the back arch, which will allow the fret slits to relax slightly. I’ll also condition the fingerboard so it isn’t as dry and less prone to cracking. Then I’ll heat each fret with a soldering iron which will help soften the glue and release the wood’s natural oils and help the fret pull out without incident. Again, it’s important to use the right tool: I don’t remember what I used on my first bass, but these days I use some small end pliers that are sanded flat to stand under the fret.

I’ve gotten pretty good at it over the years, so I didn’t have to fix a fretboard chip (this time). The next step was to prepare the waistband slots for these fillings, so I cleaned them up with a Dremel tool attached to a solid base. This removes glue, wood, and dirt from the waistband slot while ensuring an even depth.

With wooden fingerboards, I choose to fill the fret slots with a wood veneer. Most people prefer a line that is visible, so in this case I used maple to fill in the slots. I prefer using wood instead of plastic because unlike the fingerboard, the plastic can wear out and just feel weird.

Installing waistlines takes some finesse and attention to detail. Some fret slots are curved on the underside to match the radius of the fingerboard. So every maple fret line needs to be cut to fit. A radius gauge and a razor blade will do it.

I use wood glue to install the maple lines. This creates a much stronger bond than superglue and allows some labor to get the maple properly seated in the slot.

Now the fun part: cut off the maple lines. I start with a super sharp chisel, and once I get it close to the board I flood the maple with thin superglue that fills the pores and prevents rosewood dust from getting into them and obscuring the line. Then I knock off the high spots with a flat sanding block.

Now the most important part: level the board. This is absolutely critical to getting right – if the board isn’t perfectly level, there will be notes that won’t speak properly. The key to a good sounding fretless sound is optimizing the “mwah” sound, and to get that sound the strings must be close to the fingerboard. The lower the string action, the more critical it is that the board is absolutely perfect – even a slight variation disturbs the string vibration and makes notes sound strange. We use our PLEK machine to level our fingerboards, both for fretless instruments and during the re-fretting process. As a result, the boards are leveled according to our specifications, the radius is cut and the perfect relief is built in with an accuracy of 0.01 mm.

After the instrument has gone through the PLEK process, the fingerboard needs to be smoothed to remove the machining marks. This is where an experienced technique comes into play – it takes a lot of experience and technique to sand the board smooth and not compromise the PLEK quality. There is a common misconception that the PLEK machine does all the work, but it is only a tool for a skilled guitar technician.

We sand our fretless boards smooth with a flat block from 300 grit to 1000 grit sandpaper. This makes the board feel ultra smooth and fun to play.

That’s it – no more frets! Once the relaxation is complete, the neck goes back on the body for a new bone nut and setup. This jazz bass plays a lot better than my Peavey B-Quad when I first ripped the frets out over 20 years ago. But nobody comes out of the womb and knows everything, and practice makes perfect … except maybe on my intonation, which still needs work …