Converting a 5-string bass to a fretless

Lutherie Blog

Converting a fretted 5-string to fretless

     I had been wanting a fretless bass for a little while and recently a friend was selling this fretted 5-string bass for $50. I decided it was time for a little project and picked it up with the intention of pulling the frets and filling the fret-slots to convert it to a fretless.

Not bad for $50

I purchased the bass sight unseen since it was cheap and I planned to do a lot of work on it anyway. Evaluating the setup it was pretty horrendous: The action was crazy high with the saddles bottomed out onto the bridge, the neck had upwards of .050 relief, the nut needed a dressing, the electronics were scratchy and the output jack needed to be replaced. It also turned out that the truss rod was nearly maxed out already and the relief pattern was very strange, almost live a big "V" bottoming out at the 11th fret. These instruments sell for under $300 new and with the amount of work this one needed I'd say that it was worth just about $50. To correct the relief in the neck fret-removal and planing of the board would be required so it's lucky that I was already planning on doing it I guess.


After taking detailed notes on all the set-up aspects I've observed, I remove the strings and remove the neck from the body and find this in the neck pocket.
Nice! just what I wanted to see- a bunch of crazy shims...
 That's always a good sign, right? Finding more than 1/4" of various shims in the neck pocket and still having high action is a bit alarming but let's see how everything turns out. Lets get a list of what I need to do to convert to a fretless:

  1. Remove the nut
  2. Mask off or remove tuning machines closest to the nut
  3. Pull the frets
  4. Clean the fret slots
  5. Plane the board
  6. Fill the fret slots
  7. Sand board to 320 grit
  8. Re-attach neck
  9. String and setup

1. Removing the Nut

I use a quick, sharp blow with a hammer and a piece of wood to crack glue bonds and loosen the nut

2. Removing necessary tuners

Remove the tuners closest to the fingerboard to prevent sanding scratches on them

3. Pulling the frets

To remove the frets I use this solder tip that I've modified to have a little crescent shape at the tip
The crescent shape allows me to heat the frets without slipping off of them to melt any glue that might have been used in installation
Once I've heated the whole fret I begin at one end of the fret with my fret pullers and follow the soldering iron across the fret gently squeezing the pullers to coax the fret from the slot
Check out the difference heating the fret will make: the top fret I didn't heat long enough to melt the adhesive in the slot and it pulled checks of the board with it, the bottom fret pictured came out nice and clean after I applied more heat to it

All frets removed!

5. Planing the board

I've removed all the tension from the truss rod and Yikes! not the flat board that we'd ideally like to see

     Ok now we have all the frets removed and at this point I clean out the fret slots with my Japanese saw. Now we want to evaluate the neck. I remove all tension from the truss rod and see how the board looks. As you can see above it's not a pretty sight. For a fretless bass I want the option at least of setting it up with a completely flat board or no relief. To achieve that here we need to do a lot of work on this fingerboard. So I grab my glass block and some 80 grit sandpaper because I want to remove a lot of material. I decide that I'll have to remove material from both ends of the fingerboard to achieve the straightness I need. I spend the next hour or two sanding and checking the progress with various straightedge lengths repeatedly.

I separate a sheet of sandpaper into thirds and simply wrap them around the glass block

Did I mention I had to remove a lot of material?

 6. Filling the fret slots

     Finally! I've reached a result I believe I'm happy with, though its not perfect. After cleaning out the fret slots again with my Japanese pull saw I prepare to fill the slots with wood dust. I choose to use some Myrtle dust that I saved from sanding the back and sides of the OM style acoustic I built years ago. Its a nice light color that will contrast well with the rosewood board and clearly mark the old fret locations because I'd be lost without them. I pack the dust into the slots as tightly as I can with multiple applications then use a mini pipette to drizzle thin super glue all along the dust filled slot.

Its always a good idea to save different kinds of wood dust whenever possible to use in repairs
Dust packed into the fret slots
Applying the glue

7. Sand board to 320 grit

     In this case I had to repeat the last two steps of packing the dust and gluing again to fill the slots completely. Now I can sand the board again to really make the fret slots and board flush. I work my way from 80 through 120, 220 and 320 and oil the board. 

8. Attach the neck

     I decided to attach the neck with no shims in the neck pocket and evaluate it strung the the new flat-wound strings I picked up. As expected the neck angle is atrocious, so much so that I'm willing to do something that I'd never do and sand the back of my neck where it sits in the pocket on the belt sander. I repeat this is probably the only instance where I will perform this. 

Do not try at home! Permanently changing anything about how the neck fits in the pocket can be disastrous. Shims usually work fine to shift the neck angle slightly, but needing 1/4" or more of shim material and the sketchy joint that might produce lead me to dire measures. Here I've changed the angle on the back of the neck where it fits in the pocket.

9. Stringing and setup

     With the new flat-wound strings and no frets and well as changing the angle that the neck joins the body leave the setup needing a lot of work. I am able to achieve the very small amount of relief that I wanted, but remember how I said that the sanding job wasn't perfect? That's what I get for trying to cut a corner, the neck still has a now more subtle v shape to it which is causing a buzz where the 11th fret would be. So off comes the neck and nut and sanding commences once again. Ah now its actually looking good! I re-assemble everything and oil the board again. This time the setup comes out great and the board is smooth as butter. After changing out a bad output jack I'd say this bass is ready to rock. 

Now that I've done $400 of work to a $50 bass my first impulse is that I should probably put some good pickups in there too. Ah, the addiction keeps feeding...
She actually came out pretty great, I'm going to have a lot of fun

     Thanks everyone for reading! Visit my Shane Dooley Music and Dooley Guitars Lutherie sites here

Happy Music Making!!

Shane Dooley