BANDING A TEMPORARY PATCH ON A PIPE. EE STARTED TO LOAD THE BANDING TOOL WHEN HE DISCOVERED AN OLD PIECE OF BAND IN THE TOOL. WHEN HE WAS HOLDING THE TOOL WITH HIS LEFT HAND & USING CHANNELLOCK PLIERS WITH HIS RIGHT HAND, THE OLD PIECE CAME OUT FASTER THAN EXPECTED, CUTTING HIS KNUCKLE ON LEFT THUMB - 3"" IN LENGTH.