I know that the OP is interested in doing this conversion for the experience. Am I alone in thinking that he would be better served by learning how to install frets on a neck that doesn't have them? After all, a purpose made fretless neck would never need frets removed in the first place. But all necks begin life fretless until the steps are taken to install them.
That was exactly did. I used a maple veneer to accent the playing positions. I used a small saw blade to clean the slots. I used expoxy lacquer and strung up half round or pressure wound strings.
If you don't like maple, you can also use dark wood and drill for white side dots as markers.
Did someone say epoxy?
I imagine that youre not silly enough to try this on maple.
Tape helps minimize the chipouts but don't bank on it. Mix any similarly colored wood dust with the epoxy and go to town.... until the next stage of sandimg and leveling.
I know that the OP is interested in doing this conversion for the experience. Am I alone in thinking that he would be better served by learning how to install frets on a neck that doesn't have them? After all, a purpose made fretless neck would never need frets removed in the first place. But all necks begin life fretless until the steps are taken to install them.