A hand-held apparatus for repairing a defect in an outer jacket of an elongated wire or cable includes a portable die and a source of a settable material. The die has a first portion connected by a hinge to a second portion. They cooperatively define a channel in a closed configuration. The source is connected to the channel through an opening between the inlet and outlet. A heating element is adapted to heat the settable material into a flowable condition and a control circuit is adapted to vary the supply of heat. The die is juxtaposed around the jacket near the defect. As the settable material is introduced into the channel, the wire or cable is moved along the channel relative to the die in the closed configuration such that a coating is formed over the defect. When the die is removed, the settable material sets into a solid condition.