A method of manufacturing a stator bar in large dynamoelectric machines, with the bar insulation made of solid materials with high thermal conductivity and high dielectric strength. In the present invention, the bar insulation is provided by thermally conductive shells whose inner cavity conforms to the bar stock. The manufacturing process comprises slipping one or more thermally conductive shells at the substantially central straight portion of the bar stock, bending the ends of the bar stock to form end-arms, insulating the end-arms with tape or extrusion insulation and bonding all members to form a solid stator bar. In short, the bent end-arms are insulated by the tape or extrusion insulation while the straight portion of the bar is insulated by the thermally conductive shells. This greatly increases the effective thermal conductivity of the stator bar. The high dielectric strength of the materials significantly reduces the wall thickness of the bar insulation. The space freed by the thinner bar insulation can be filled beneficially by copper or iron thereby reducing the size of the machine. The high thermal conductivity of the bar insulation will increase the life of the stator bar, while the thinner bar insulation will reduce the size of the machine.