A kerf splitter like the one shown at left will help prevent a circular saw blade from binding in its kerf and kicking back. Choose /Gnch hardboard for the splitter piece and %-inch plywood for the shoulders; refer to the illustration for suggested dimensions. Fasten the three pieces together with screws. To use the jig, start the cut, turn off the saw, and insert the splitter in the kerf a few inches behind the saw. Back up the saw slightly, then continue the operation (left). For particularly long cuts, advance the kerf splitter periodically to keep it near the saw.