After returning from Portland, OR where the high temperature was a cool 78 degrees for 6 days, we walked off the airplane into 95 degrees at 11:00 PM. Needless to say we wanted to go back to Portland but Austin is home. The next two days were rest days with nothing accomplished on the project.
I finally decided to go to the garage and practice drilling plexiglass before drilling the windshield. I should have practiced much more before drilling the canopy since I have some chips and small cracks that I hope will drill out when I enlarge the holes. I also read a lot more of other's problems on Van's AF forum. I think that I will enlarge the holes on the canopy that are riveted to the bows to 3/16" and put a 1/32" wall thickness tubing bushing into the hole before riveting. This should keep the plexiglass from touching the rivets which would transmit vibration. This would, in theory, stop vibration stress to the plexiglass.
I finally decided that drilling slowly with a wooden block backing up the penetration side of the plexiglass should eliminate most of my problems. I reread Van's procedures chapter and sure enough that was what I had missed. I thought the special plexiglass bits were supposed to make it easy, yeah sure!
