The smooth, varnished wooden handles on bar clamps look slick. But they're too slick to grab tightly when you screw down to create serious clamping pressure. To get a better grip, I carve grooves along the length of the handles with a motorized rotary tool and a ball cutter. A few grooves spaced around a handle makes clamping (and unclamping) lots easier. —Ian Ross, Smiths Falls, Ont.