An apparatus and method for coupling ends of two insulated conductors includes coupling a core of a first insulated conductor to a core of a second insulated conductor. Exposed portions of the cores are located inside a box. Electrically insulating powder material is placed into the box and a force is applied to first and second plungers to compact the powder material. Additional electrically insulating powder material may placed into the box and a subsequent force applied to compact the powder material into compacted powder material that surrounds the exposed portions of the cores. The compacted powder material is formed into a substantially cylindrical shape. A sleeve is placed over the compacted powder material and coupled to the jackets of the insulated conductors.