On March 12, 1994, at approximately 1745 Alaska standard time, a wheel equipped Piper PA-18 airplane, N3485Z, collided with terrain during the landing rollout on runway 7 at the airport in Soldotna, Alaska. The pilot-in-command/flight instructor and his student, who was also the registered owner of the airplane, were not injured and the airplane sustained substantial damage. The instructional flight was conducted under 14 CFR Part 91. At the time of the accident, visual meteorological conditions prevailed and there was no filed flight plan in effect for the flight. The flight instructor reported that he was demonstrating to the student a wheel landing to show the proper use of throttle and pitch control for a smoother touchdown. The instructor said that he made a normal approach and normal wheel landing. At idle power when the tailwheel contacted the runway, the airplane initially tracked down the centerline of the runway but then began to veer toward the right side of the runway. His judicious application of left rudder pedal did not arrest the plane's divergent heading. He reported that he then applied the wheel brakes lightly to slow the plane at which point the plane nosed over. The instructor said that the plane's brakes were not locked up as there were no tire marks on the runway.