A hot bolt clamp and method for repairing a multi-bolt flange of a pipe. The clamp has enclosures that can be assembled around the multi-bolt flange. The clamp has a central opening extending through a first enclosure face and a second enclosure face for the pipe. The clamp includes a flange bolt cavities extending through the enclosure faces configured to enclose flange bolts and having a cutter channel connected to each flange bolt cavity. Restraint bolts extend through the enclosure face to restrain the multi-bolt flange. Flange bolts can be removed and replaced during the repair operation. A cutter tool apparatus can be extended through each cutter channel for use in removing stuck flange bolts. The clamp forms an injectable void around the multi-bolt flange that is injectable with sealant in the event of a loss of gasket integrity during the repair operation.