Patent ID: 7141754

Claim:
A method for repairing a defect in a conductive substrate using welding, the substrate having a first surface and a second surface, the method comprising: a) placing a consumable filler slug in contact with the defect; b) applying a sacrificial retainer in contact with at least a portion of the consumable filler slug; c) placing at least one electrically conductive cover sheet in contact with at least a portion of the sacrificial retainer, the cover sheet having a melting temperature higher than that of the conductive substrate, the consumable filler slug, and the sacrificial retainer; d) placing a first electrode and a second electrode in contact with the at least one cover sheet and transmitting electrical current from the first electrode to the second electrode for a period, thereby resistively heating the at least one cover sheet and conductively heating a portion of the sacrificial retainer, a portion of the consumable filler slug, and a portion of the substrate resulting in coalescence in a substantially liquid pool that substantially fills the defect, the first electrode and the second electrode applying pressure to the substantially liquid pool; e) cooling the substantially liquid pool to solidification under the pressure of the first electrode and the second electrode producing a repaired substrate; and f) removing the at least one cover sheet from the repaired substrate.