Method of making an electrical aluminum or aluminum alloy conductor provided as a wire comprising: an electrically conductive core having an outer surface, the core comprising aluminum; and an electrically insulating coating chemically bonded directly on the outer surface of the core, the coating comprising at least one non-aluminum metal oxide, wherein the at least one non-aluminum metal oxide comprises titanium dioxide, wherein the electrically insulating coating maintains an electrical resistance of at least 3 Megaohm per centimeter at ambient temperature after thermal cycling to at least 600 °C, wherein the method comprises: contacting a bare wire with a bath containing an aqueous solution with a precursor for the electrically insulating coating including the element Ti, the bare wire providing the core; operating an electrification device in electrical communication with the bare wire to electrify the bare wire with a peak voltage potential of at least 140 volts up to 800 volts and an effective current of at least 20 amps and up to 1000 amps per wire and such that the bare wire acts as an anode; and electrochemically reacting the bare wire with the precursor in the bath to deposit the electrically insulating coating on an outer surface of the wire thereby producing the coated electrical conductor. an electrically conductive core having an outer surface, the core comprising aluminum; and an electrically insulating coating chemically bonded directly on the outer surface of the core, the coating comprising at least one non-aluminum metal oxide, wherein the at least one non-aluminum metal oxide comprises titanium dioxide, wherein the electrically insulating coating maintains an electrical resistance of at least 3 Megaohm per centimeter at ambient temperature after thermal cycling to at least 600 °C, wherein the method comprises: contacting a bare wire with a bath containing an aqueous solution with a precursor for the electrically insulating coating including the element Ti, the bare wire providing the core; operating an electrification device in electrical communication with the bare wire to electrify the bare wire with a peak voltage potential of at least 140 volts up to 800 volts and an effective current of at least 20 amps and up to 1000 amps per wire and such that the bare wire acts as an anode; and electrochemically reacting the bare wire with the precursor in the bath to deposit the electrically insulating coating on an outer surface of the wire thereby producing the coated electrical conductor. contacting a bare wire with a bath containing an aqueous solution with a precursor for the electrically insulating coating including the element Ti, the bare wire providing the core; operating an electrification device in electrical communication with the bare wire to electrify the bare wire with a peak voltage potential of at least 140 volts up to 800 volts and an effective current of at least 20 amps and up to 1000 amps per wire and such that the bare wire acts as an anode; and electrochemically reacting the bare wire with the precursor in the bath to deposit the electrically insulating coating on an outer surface of the wire thereby producing the coated electrical conductor.