Kerfing — Lutherie Encyclopedia

KerfingType: glossarySlotted or notched strips of wood glued along the inside edges of the sides to provide a gluing surface for the top and back.## Definition Kerfing, also called kerfed linings, consists of strips of lightweight wood, usually spruce, mahogany, or basswood, that have been saw-cut (kerfed) at regular intervals along one edge. These cuts allow the otherwise rigid strip to flex and conform to the curved interior edges of the guitar sides. Kerfing is glued along the top and bottom edges of the sides, where it provides an increased gluing surface area for attaching the soundboard and back plates. There are two common styles: triangular kerfing, which has a roughly triangular cross-section and is stiffer, and standard sawn kerfing, which is rectangular in cross-section with closely spaced saw cuts. Reverse kerfing has the solid edge glued to the sides and the slotted edge facing inward. ## In Practice Installing kerfing is a fundamental step in guitar body construction. The builder applies glue to the unslotted face of the kerfing strip and presses it against the inside edge of the sides, securing it with dozens of small clothespin-style clamps or specialized kerfing clamps. The kerfing must follow the side contour smoothly without gaps. After the glue dries, the kerfing is trimmed and sanded flush with the edges of the sides, creating a flat, uniform surface for the top and back to be glued onto. In areas of tight curvature, such as the waist or a cutaway, additional kerfs may be cut to help the strip bend. Careful kerfing installation ensures a strong, continuous bond between the sides and plates.