Abstract: Apparatus for repairing insulation of an insulated conductor comprising a split yoke; an elongate, substantially cylindrical cavity formed in the mating surfaces of the yoke; an elongate, split, substantially cylindrical conductor mold or insert removably positioned in the cavity; an injection molding unit communicating with an opening in the conductor insert through an injection bore in the yoke to inject insulator into the conductor mold through such bore; a heating element within the yoke to melt the injected insulator over an area comprising the central area of the conductor mold; and a cooling element within the yoke to cool the ends of the conductor mold while the central area is heated, whereby the heat applied to the insulated conductor within the conductor mold does not extend to insulated conductor outside the yoke. In an optional embodiment, a tensioning device can be used to maintain the insulated conductor under tension during the repair.