We have come across something similar, it was a retractable aluminum shade that went over a greenhouse. It was very close to the glass but not it contact with it. We used CC550*, it came out looking fantastic.
*Please follow all saftey instructions. I’ve used it for 11 years with great success.
This is true… my buddy who works stage here was given a partner and right away thought he was strange. Next thing you know the guy is wearing brass squeegee clips on his ears like ear rings. My buddy asked what he’s doing and the guy said it’s to keep the government out of his thoughts or something like that. That was it for him, down to the ground and got the boss to fire him.