Fret crowning takes me forever – I probably spend 20-25 minutes crowning each fret, and the results aren’t as good as I’d like. Here’s a list of things I think I’ve been doing wrong:
- Pressing the file firmly to the fret
- Changing the angle between the top of the fret and the face of the file as I go.
- Starting polishing with low grit sand paper (220).
Doing it this way, the crowns of the frets look like the top of a school bus. Round but mostly flat on top, which, for what it’s worth, is how a lot of frets (mostly jumbos?) look like. I’m aiming for a crown that is more like a half sphere. It’s impossible to get it, but I’d like to get close. Here’s what I’m going to try next:
- File lightly.
- Don’t change the angle of filing. Keep filing at the same angle, the fret top will get narrower and narrower.
- Start polishing with
600400. EDIT after leveling and crowning the frets on the Jazzmaster: I needed to use 400 to take out the file scratch marks. Also, I had to be stubborn and flap over some frets several times until the marks were gone.
The first and last points are related. Pressing the file firmly to the fret leaves chatter marks, and to remove those marks it’s needed to start polishing with a low grit sand paper. Pressing lightly should leave no marks, so then it’s possible to start with 600 grit. I think that starting with 220 (or other coarse grit) will remove more material than intended, therefore squaring off the fret top. The 600 grit paper should just round the tops.