Brief Description: Worked on skin, got #4 cylinder piston out.
On Saturday I stopped by the airport and checked the cylinder. The piston had moved out a couple of inches. In moving it I let the connecting rod hit the piston skirt and knock a chunk out of it. Scratch one piston. Disconnected the air for the weekend.
Cut rectangular lift strut opening and round inspection hole. Riveted cover plate reinforcing ring in place. Match drilled all #40 holes. Marked but did not drill larger holes - waiting to look at wing members first.
Tapped the piston back into the cylinder a ways, and reapplied air pressure. Piston came back out as before. Repeated two or three times and finally the piston blew out of the cylinder. Piston rings severely corroded as expected. Cylinder wall questionable. Will have to remove the valves and clean up the walls thoroughly to see if they are beyond repair.