Make a perfect square from a round hole
When covering a screwhead with a round plug, carefully matching the grain and color of the plug to the surrounding wood can make the plug nearly invisible. But just as often, what looks perfect in the raw emerges as an unsightly dot during finishing. Using a slightly protruding square peg in a contrasting wood species turns a cover-up into a design element.
In the usual method of drilling a round hole and squaring it with a chisel, the challenge is forming a clean-edged, perfectly square mortise. Using the lid panel (F) as an example, here's how to get flawless results.
Chuck a 3⁄8 " Forstner bit into your drill press, and position the fence and a stopblock to center the bit on the peg (G) locations on the panel (F). Drill a 1⁄8 "-deep hole at each corner, as shown inset. Remove the Forstner bit, and chuck a 3⁄8 " hollow mortising chisel (the type made for a mortising machine) into the drill press, aligning the chisel edges with the panel edges. (Visit grizzly.com for an inexpensive 3⁄8 " mortising chisel.) Lower the drill-press quill, as shown at left, driving the chisel into the wood 1⁄8 " deep. Clean out the mortises with a 1⁄4 " hand chisel.