Lay a bastard ﬁle on a workbench and ﬁle the scraper’s long thin edges ﬂat, smooth and at 90 degrees to the sides of the tool.
Polish the two sides and the narrow edge on a sharpening stone. This removes the burr created by ﬁling and leaves a sharp 90-degree angle along the scraper’s edge.
Use a burnisher ($10)—or the shaft of a chisel, carving gouge or screwdriver—to create the cutting edge. (The metal you use for burnishing needs to be just a little harder than the scraper.) Push down on the burnisher while sliding it along the scraper’s edge. The burnisher’s harder steel presses the scraper’s edges to one side to create the cutting edge. Make three to four passes with the burnisher and feel the scraper’s edge with your ﬁnger; stop burnishing when the edge feels like a light wire. Now test the scraper on a piece of scrap wood.
Hold the scraper in both hands, angled toward you, and ﬂex it to create a slight belly in the center as you pull it along the wood. Press down ﬁrmly—if the edge is sharp, you’ll cut thin curls like a plane. When the scraper starts creating dust or begins to chatter, it needs reburnishing. Beware! In heavy use, a sharp scraper can get hot and burn your ﬁngers. Pause frequently to brush away the curls and check your progress.