While building the candle lantern featured in Woodcraft Magazine (“Illuminating History,” March 2005), I needed a way to sand the inside of the hand-cut slot in the front of the top plate; it’s only ¼" wide.
To solve the problem, I used sandpaper attached to a putty knife. You simply cut the sandpaper slightly oversize for a 1½" x 3" blade and attach it with spray adhesive, then trim to fit. I keep two versions handy: one with with 80-grit on one side and 120-grit on the other side, and the second equipped with 150- and 180-grit.
