After I had some scrap material I did several drilling tests. I dressed some drills per Sonex’s instructions and drilled a lot of test holes. I never had any problems. Then I used both some undressed drills and plexiglass drills. I never got a hole without a crack with the normal drills. The second picture is from the first hole I drilled with a plexiglass drill. The best I can say was, the material exploded. To be fair, my brother talked about speeds and feeds for the plexi drills and I was able to drill some clean holes, but the Sonex dulling method worked far better and those are what I would use.
Picture number three shows the tape line for the rear cut and picture four shows the Canopy after the first two cuts.
