A method for insulating wires is disclosed. A portion of the plurality of wires and an insulating material are placed in a tube having an open end. Pressure is applied to the tube. During the application of pressure, the tube, the plurality of wires, and the insulating material are heated to a temperature above a melting point of the insulating material. As a result, the insulating material is melted and driven toward the open end of the tube. Upon removal of the heat, the insulating material solidifies and forms a barrier proximal to the open end of the tube.