In 2018/2019 we made a half-dozen Strat and Tele necks from what, to me, was special wood: some very old Honduras mahogany I had saved for over 40 years, and some spalted maple that I got from the Amish nearby. The necks are skunk-stripe-style and made with a 7¼" radius. These are still destined for several guitars I am making, but since then I have decided I want them to have a 9.5" radius for various fretting and setup reasons. These necks have shop-made single action rods — some heel-adjustable, some peg-head-adjustable.
Since the necks have no fretboard, and side dots that are much lower than the fretboard edges, and thick tortoise fret dot markers, there was plenty of room to make it work.
Leveling the center, then widening out
Starting narrow on a 4" block.I started leveling in the center with 120-grit on a 4" radius block using three different widths of sandpaper, from narrow . . .
Stepping up to a wider strip.. . . to wider . . .
Full coverage at last.. . . to full coverage, in order to “knock down” the high center quickly but gradually, without touching the outer edges of the fretboard until I switched to full width.
Marking, sanding, scraping.I continued marking the surface, sanding with 120-grit on a 4" block and also scraping in areas — end to end — with a scraper made from a radius gauge.
Turning a radius gauge into a scraper
Sharpening the flats.I sharpened the flat sides of an SM steel radius gauge . . .
Filing the edge.. . . filed the edge sharp with a smooth mill-file . . .
A purpose-built curved scraper.. . . and it makes a good scraper.
Hunting down a high spot
Pencil over the rise.There was a small rise on the bass side way up the neck; I penciled over it.
Masking the block.Then I put masking tape on the sanding block, exposing only the penciled area to be sanded.
Almost there.It didn’t take much sanding to eliminate the rise.
Gone in a minute.Gone in a minute!
Cross-sanding to blend it all in
Cross-sanding, near side.Then, with a full-length radius beam covered the full length with 120-grit, I sanded crosswise to smooth in all the sanding and scraping spots. Holding the beam firm and rigid, moving with stiff elbows and square shoulders, I’d start on the near side . . .
…and back to the far side.. . . and go to the far side, back and forth.
Finishing lengthwise through the grits.When my remaining pencil lines were almost gone, I switched back to a 4" block going lengthwise, using 120, 220, and 320-grit sandpaper.