Q: It seems, no matter how careful my technique or sharp my bit, that any time I rout a decorative edge or create a molding, somewhere along the edge I will get router burn. I hate to completely redo an entire piece for just a small area. Is there some way to remove this discoloration?
A: Burn marks on wood result from excessive heat generated by some machinery operation. You can scorch a board while sawing it, drilling it, routing it, even sanding it. Of course, the best strategy for dealing with burn marks is avoidance. Keeping blades and bits both clean and sharp is important. Using good technique, as you indicate, is also important. When profiling an edge, you must feed the router (or, on the router table, the workpiece) briskly and continuously. Every hesitation or pause can result in a burn, especially if you’re working a susceptible wood like cherry or maple. Planing, scraping, filing, and sanding will remove burn marks. But you must work carefully. The hazard is that you’ll distort the profile or contour. Take your time. Use a crisp-edged sanding block or a detail block matched to a contour’s proportion — a convex block for a cove, a concave block for a bead. Begin your work some distance from the burn so you don’t produce an obvious hollow in place of the burn. Depending upon the location and extent of the burn, a redo actually may be the best option. You often can, for example, joint the edge that guides the router, then re-rout the profile, removing the burn. The operation can be faster than a lot of persnickety hand-sanding and yield a crisp, unblemished profile.