On July 25, 2009, at 1230 central daylight time, an amateur built experimental RV-6, experienced a rudder pedal failure which resulted in a loss of directional control and a landing gear collapse while landing at the Whitman Airport, Oshkosh, Wisconsin. The pilot and passenger were not injured. The airplane was substantially damaged. The personal flight was operating under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed. The flight departed from the Muscatine Municipal Airport (MUT), Muscatine, Iowa, at 1100. The pilot reported that during the landing roll the right rudder pedal welds failed. The airplane turned to the left into the wind and departed the left side of the runway. Because he had no right rudder or right brake authority, the pilot applied left rudder and brake in order to avoid a ditch which paralleled the runway. The right main gear collapsed and the firewall was damaged. Inspection of the airplane revealed the left seat, right rudder pedal had failed. The rudder pedals were tubular and the upper welds where the vertical tubes are connected to the cross-member had failed.