What was found
WHILE DEFUELING THE AIRCRAFT PREPATORY TO PAINTING, IT WAS DISCOVERED THAT NO FLOW COULD BE ACHIEVED THROUGH THE RIGHT DEFUEL FITTING. THE DEFUEL WAS ACCOMPLISHED BY TRANSFERRING ALL OF THE FUEL TO THE LEFT TANK AND REMOVING IT THROUGH THAT VALVE. WHEN WE OPENED THE RIGHT TANK A SHOP RAG WAS FOUND PLUGGING THE DEFUEL PORT. IT HAD OBVIOUSLY BEEN LEFT IN THE TANK DURING PRIOR MAINTENANCE.