Cut a 1-foot section of serving thread from a spool. Wrap the thread around the bow string 2 inches below the damage. Tie a single overhand knot in the thread. Pull each end of the thread to the opposite side of the knot and tie another overhand knot. Continue alternating the knots until you are 2 inches above the damaged section. Tie a double overhand knot on the final wrap to secure the serving repair. Cut the ends of the serving thread, leaving a small tag on each.