What was found
AFTER REMOVING RIGHT FUEL TANK TO CHECK FOR LEAK, FOUND WEAR ON BOTTOM OF TANK INDENTED WITH RIVET HEAD MARKS. THE TANK RESTS ON A REINFORCEMENT PLATE THAT IS RIVETED TO STIFFENERS. USING A UNIVERSAL TYPE RIVET HEAD, A RUBBER CHAFE STRIP IS LAID OVER THE RIVET HEADS, BUT DUE TO WEIGHT AND MOVEMENT OF THE TANK, THE RUBBER HAS MOVED IN SPOTS REVEALING BARE RIVET HEADS. ALSO, RUBBER HAS BECOME BRITTLE AND HARD. IF LEFT UNCHECKED, RIVETS WOULD HAVE WORN THROUGH TANK IN MULTIPLE SPOTS. SUGGEST COUNTERSUNK RIVETS.