I recently had a rather attractive blonde Hofner New President arch top through the workshop which had worn frets and needed a fret dress.
The first thing, before I can level the frets, is to remove the old nut. In this case the ends of the original nut were covered in a thick layer of lacquer. To avoid chipping when removing the nut, this area of lacquer had to be carefully removed beforehand. Once the nut was removed it was evident that there was quite a layer of glue used in the original factory installation, which would need to be removed before a new nut is fitted.
Sometimes it is possible to reuse the old nut after a fret dress but in this case a new nut would have to be made as the old one no longer fitted properly due to the lacquer removed from the ends.
The fret dress is done in three stages - levelling the frets, crowning the tops, and sanding and polishing. The top of the guitar is protected and strapped firmly in the neck jig and the neck adjusted as straight as it will go by adjusting the truss rod. The pickup is covered and taped off to prevent metal dust from the levelling getting into the pickup windings.
The fretboard is taped off to protect the fretboard and the fret tops marked to show where the levelling bar is hitting the frets during the levelling process.
As the tops of the frets have now been levelled (flattened essentially) they have to be re-profiled to reinstate rounded fret tops.This is done with a luthier's file designed for the job. The frets are then sanded and polished. Completed fret dress below....
Turning to make the new nut, a bone blank slightly thicker than the slot is picked and sanded to the correct thickness, then sanded and shaped to fit the width of the nut slot, for a snug fit. The height of the nut is sanded to a workable height and the correct string spacing is located and the string slots filed just enough so that the guitar can be restrung and the strings are held in place.
The nut slots are then filed to the correct depth. Excess material is removed from the top of the nut so that the strings are exposed in the slots. If a nut slot is too deep a string can catch up in the slot and cause tuning problems. The nut is removed for filing, sanding and shaping several times during this process. The shaped and completed nut is polished and installed below..
The guitar is set up, making adjustments to the truss rod and bridge to get a fairly low action across the fretboard. Now playing very sweetly. Some pictures of this very fine blonde beauty!