EE WAS USING A 45-LB JACKHAMMER TO REMOVE SCALE UNDERNEATH #7A HEATER BECAUSE A RESTRICTION IN THE BACK END OF THE HEATER WAS PREVENTING SLURRYAND LIQUOR FROM DRAINING OUT. WHILE HE WAS WORKI NG UNDERNEATH THE HEATER, A PIECE OF SCALE STRUCK GUN CAUSING THE JACKHAMMER TO PINCH HIS FINGERBETWEEN IT AND A LADDER STAND. BECAUSE OF THE TYPE OF FRACTURE, A SURGICAL PROCEDURE WAS REQUIRE