I make a habit of saving used sandpaper from about 300 grit to 500, I use it to rough polish the frets….
I cut ‘em in to small pieces, and give each fret a good going over… watching the reflected light off the crown to see when all the tooling marks are gone..
the tape above is to hold the proctor down while I took the photo with the hand that would normally hold the protector… this stuff is complicated ain’t it….
Once that is done, I move on to wet sanding the neck. I just use 800 grit here with mineral spirits as a wetting agent and a small, about 1 ˝ inch square block..
I think I have mentioned this before, but there is a considerable difference among the various brands of wet or dry sandpaper. Some of the types available at your local hardware or Home supply store may be inferior to the good stuff, which is why the good stiff is called good… I use 3M Imperial, it cuts fast and lasts long….
I begin on the face of the headstock… wet it with your wetting agent of choice and give ‘er a go…
Ron Kirn