Abstract: A fiber glass fabric reinforced wood sound board for a guitar is made by placing a sheet of wood in a shallow mold cavity with a layer of fiber glass fabric overlying an associated surface of the wood sheet, spreading a layer of liquid resinous compound over the layer of fabric to impregnate the fabric, providing a plate having a smooth surface, positioning the plate with its smooth surface in face-to-face engagement with the layer of liquid impregnating material to provide a substantial closure for the mold cavity, drawing vacuum on the mold cavity, and curing the liquid resinous material.

Abstract: A guitar has a separate body and neck each made of a metallic frame combined with a mass of structural foamed plastic. A solid joint, involving metal to metal contact of the two frames, is provided between the body and the neck and is readily unmade to allow disassembly of the neck from the body for repair or replacement of either the body or the neck. The two frames provide a continuous metallic span from the nut to the bridge to inhibit bending under string tension and also to enhance sustain by reducing damping. The external surface of the neck and body plastic masses may be given a grain effect, color and finish causing such masses to closely simulate wood, yet the use of wood is entirely avoided to avoid its disadvantages such as its tendency to warp, crack or otherwise deteriorate with age and changes in temperature and humidity.

Abstract: A stringed instrument, such as a guitar, with a neck and a body, is constructed to provide a stiffened neck adjustable to compensate for bending due to string forces and also to provide a sound, easily made connection, between the neck and the body. The neck is an assembly including a metallic stiffener embeded in a main neck part and carrying a tension rod. A nut on one end of the rod tensions the rod to control bending of the stiffener and of the remainder of the neck which is fixed to it. At its lower end the stiffener includes a rearwardly extending heel through which the neck is firmly connected to the body.