A bonding probe is used for bonding a cover sheet to a core to form or repair a dual wall structure. The bonding probe includes a body, an attachment end at a distal end of the body, a head at an opposite end of the body, a tip extending from the head, and a cooling passageway. The attachment end couples the body to a resistance welder. The tip extends to form a proximate end of the body. The tip includes a contacting area having a predetermined three dimensional contoured surface. The contacting area aligns with a predetermined area of a three dimensional outer surface of a cover sheet of a dual walled structure. The cooling passageway provides a passageway for a flow of cooling fluid. The cooling passageway extends through the head, and into the tip.