Before you yank out any frets: Will the bridge permit a lower action? Photos courtesy of basslab.de

Have you always wanted a fretless bass but never had the cash to buy a new one? Good news: Assuming you have a spare bass in your arsenal—preferably an inexpensive one you rarely use—it’s an easy mod to convert it from fretted to fretless. There are many descriptions of DIY fretless conversions on the web, but I’d like to add yet another one that focuses on the reasons and alternatives behind each step.

One might argue that it can’t be too tough a job. After all, Jaco wasn’t a luthier and he managed it on his own—even without YouTube. But his conversion had to be revised by one or two luthiers because the marine epoxy (probably Pettit’s Polypoxy) he used peeled off the fretboard. We want to avoid such do-overs, right?

Before you start! Going fretless is a reversible mod, but the way back isn’t as easy and it’s not cheap. To reverse it, the fretboard first has to be cleaned from all paints, then the fret slots have to be sawn, and finally you have to re-fret the neck—not as easy as pulling frets out.

So, in case you’re not sure if fretless is for you and your spare bass has a bolt-on neck, consider simply getting a fretless replacement neck. Yes, that’s expensive, but if you’re not able to re-fret the neck on your own, bringing it back to its initial state can easily cost as much as a new neck.

Another crucial consideration: Removing the frets also means you’ll need a lower action to compensate for that missing fret height. Check that before you start (Photo 1). Will the bridge and saddles accommodate a fret’s worth of height reduction?

A lined fingerboard might sound appealing, but many experienced players prefer to only trust their ears.

Tools and materials. In addition to having a gripping tool to pull out the frets (more about that in a moment), you need a cutter knife, several grades of sandpaper, a sanding block (possibly a radiused one, available from luthier suppliers like stewmac.com), some superglue, a paintbrush, and either clear coat or some oil for the finish. Frets are often glued in and heating them with a soldering iron helps to loosen them, so maybe add that to the list.

Pulling the frets. In lutherie, there’s always a specialized tool for every job. You can get a fret puller, but that’s kind of over the top for a one-time job. A side cutter (aka diagonal pliers) should be enough to get under the fret. Use one that’s as small as possible.

Try to pull out one fret end and then slowly work your way across the fretboard. Once you’ve managed to work the first inch of a fret out, you should be able to see whether it was glued in or not. If the frets were glued, it helps to use the cutter knife to cut around them and loosen their sides to reduce the risk of chipping the fretboard.

Some DIY tutorials recommend taping the fretboard around the frets to further hold down any possible chips. I’m not sure if that works. The most probable outcome is that the chips go with the tape instead of the fret.

Filling the fret slots. Not surprisingly, the destructive part is the easiest, while deciding what to use to fill the slots is a bit more complex. Photo 2 shows a few of the possible materials. In the top image, from left to right, we have wood putty, two different veneers, and a plastic strip. The bottom image shows the result of using each material.


Possible fillers include wood putty, veneers, and plastic.

The color you choose will determine whether you end up with a lined or unlined fretless fingerboard. A lined fingerboard might sound appealing, as it seems potentially easier to navigate, but many experienced players—including the late fretless master Jack Bruce—consider it confusing and prefer to only trust their ears.

Once all the frets are removed, clean the slots with the cutter knife before you fill or glue anything in there. After the glue or putty has dried, use the cutter to remove any protrusions.

Sanding. Next, the complete fingerboard needs to be leveled using the sanding block to remove all dirt, glue, oil, and sometimes lacquer. There are a few instances where the lacquer can remain, but only if it has no cracks or dings. In the end, the weakest part determines the rigidity of the whole ensemble. If you feel unsure of the lacquer, get rid of it!

Remove the nut before you start—you’ll have to do that anyway. If your filler material sticks out, start sanding parallel to the fret slots, so you don’t rip out the filler. Sanding can take time, especially with a lacquer finish, so be patient. Sanding is boring, but crucial for a good result. And “good” means a very even surface, including maintaining the fingerboard’s radius. Even if you get bored, don’t reach for a lower grade of sandpaper.

Tweaking the new setup. Once you’ve sanded the fingerboard silky smooth, add your choice of finish, and then put the nut back in. Finally, do a careful setup. This includes adjusting the saddles and nut slots to accommodate a lower action, and possibly lowering your pickup height a tad. As you settle into playing your new fretless bass, be prepared to revisit the setup a few times until you’ve dialed in the action and feel.

Note: If you need more help with the setup and reassembly process, I’ll cover this in greater detail in my next column, so stay tuned.