Abstract: Apparatus for producing finger jointed lumber from random length boards is disclosed. Adhesive applied to the union of two boards of lumber mated end-to-end in a finger joint union is cured in a rotary bonding assembly including a stator and a rotor. Mounted on the stator assembly are a plurality of electrode plates disposed at equally spaced locations around the stator opening thereby defining a plurality of curing stations. The rotor assembly is mounted for rotation within the stator assembly and includes a plurality of electrode plates disposed at equally spaced locations and in axial alignment with the stator electrode plates. The electrode plates are adapted to conduct radio frequency current through the finger joint union of boards confined between the rotor and stator electrode plates at each curing station.