I put a once piece windshield stc in my dads 64 Cessna-182g.
At the top there was a need for a more structural attachment, so the stc called to VERY CAREFULLY drill an 1/4" hole with the special plexiglass drill, insert a piece of 1/4 poly urethane tubing in the hole and then after sliding in the windshield between the two pieces of aluminum install 6-32,
(or 8-32, I don't remember exactly), fully threaded machine screws through the holes.
The Poly Urethane tubing acted as a mini shock mount and protected the plexiglass from the machine screw threads.
