On the bench is a dulcimer getting ready to receive frets. I level and put relief into fingerboards by planing, scraping, and sanding. I first get the fingerboard flat and true and then add a few thousandths of an inch of relief in parts of the fingerboard to assure the action can be set as low as I like without causing string buzz and rattles.
I sometimes prefer to sand a fingerboard to initial flatness and use an aluminum level as a long, accurate sanding block. I checked the level with my machinist’s straightedge and was surprised to find both faces are true and straight. This is not always the case, especially on an inexpensive aluminum level.
In use I can sand with one side of the level and flip the level over to use the other face as a reference for straightness and flatness. The level is wider than my steel machinist’s straightedge so it sits more securely on the fingerboard while I measure relief, etc.
I regularly post photos of dulcimer making in progress on Instagram. You can follow me on Instagram or see my Instagram posts on this page.