Q: Can I sharpen router bits in my shop, or do I have to take them to a professional? - Bart Connelly, Houston, TX
A: You can easily restore a sharp cutting edge to router bits with just a few quick swipes of a diamond file (although professional blade sharpeners might take issue with this DIY approach). The trick is to sharpen only the flat side of the cutter, not the beveled cutting side. A half-dozen passes across a medium or fine diamond file should do the trick. You can find diamond files for honing at most woodworking stores. (EZE-Lap is a common brand that costs $10 to $15 for a set of three files – medium, fine and super fine.)
You can sharpen carbide-tip bits with a file, but in removing the carbide coating you will essentially transform the bit into a regular high-speed steel bit, which will require more frequent sharpening.
Professional blade sharpening services are a good option, especially for bits with complex profiles. Some will provide the service for as little as $2 or $3 a bit, but others may charge $10 apiece or more. - HANDY