The airplane was damaged during landing. The pilot reported that he was giving flight instruction, but during the accident he was in command of the airplane and his student didn't provide any control input. He stated that he touched down on centerline and a gust of wind lifted the airplane from the ground and weathervaned it into the wind. He stated that the airplane did not respond to rudder input and he added more power in an attempt to gain more control authority. He stated that the airplane responded and came back to the runway heading and he added full power for liftoff. He stated that he heard and felt the aircraft hit a sign. He stated that he landed the airplane without further incident. A taxiway sign was found to have been struck. The pilot reported no mechanical failures or malfunctions of the airplane. The pilot reported that the landing was made on runway 19 and the winds were from 240 degrees at 10 knots.