I’ve started a project to convert a six string bass guitar into a fretless bass. I bought an Ibanez sr206 off gumtree for $150.00. It is in perfect condition.
The first step is to remove all the frets from the neck. This is done by heating each fret pin with a soldering iron. This loosens any glue holding the fret in place and softens any wood compounds so the frets come away without damaging the neck too much.
Once all the fret pins had been pulled out (and after I’d burnt myself several times with the soldering iron), I cut the grooves to ensure they were straight edged, and deep enough to hold a sliver of wood. A hacksaw blade proved to be about the right width for the cuts I wanted.
The final neck now had clean lines cut where the fret pins once existed. There are still a few burn marks showing from the soldering iron, but these should disappear once we do the final sanding.
I am using a light wood – maple – to fill the grooves so the neck will still show the fret positions to guide the note selection. When you are playing the guitar, you don’t generally see the frets, however as they have been cut right across the neck to a reasonable depth, they will be visible across the top of the neck when playing. (The “top” I refer to here is actually either side of the neck, which is pointing upwards when the guitar is held normally)
I have had to use a double thickness of the maple sheet I ordered to fit the holes properly, so I preglued all the sheets together before fitting them into the grooves.
The next step is to glue a section of the veneer sheeting into each fret groove. I am using a very strong glue that has a slight foaming property which ensures the entire space gets filled with glue. I’ve used it before to glue down an acoustic guitar bridge and it has worked well.
During fitting, I had to sand the veneer sheet to make it slightly thinner, and I added a concave curve to the bottom edge to ensure it fitted the groove snugly. Once the glue has set fully, I cut back the excess wood and glue protruding from the neck, and sanded the top of the neck back to a rough finish with an appropriate luthiers sanding block. For the SR 206 this has a 16 inch diameter curve.
I did the first four fret grooves first as a test to make sure my technique was working OK, and I’m quite pleased with the result so far. The use of a double thickness of veneer gives the finished wood a slight pinstripe line down the middle which adds an air of professionalism to the final result.
After completing the first four frets, I then glued in all the remaining maple spacers.
Here’s a close up, showing how the glue I am using foams up filling any spaces or cracks you may have missed…
I left the glu to dry overnight, and then cut the inserts back as close to the neck as possible, and started to sand away any excess wood and glue.
After sanding back down to the fret board, I continued sanding with the rough paper until I was sure the while fret board was correctly shaped.
Finally, I progressively sanded the whole surface with several sheets of progressively finer paper. The final sanding down was done with wet and dry paper and Orange Oil – similar to french polishing.
The final result is very smooth, and the visible maple lines are not noticeable when you run your fingers down the fret board.
Finally, I sanded down the top saddle to give the guitar a much closer action, and assembled the guitar again.