N1EDM,
In keeping with the original idea.......
Glassing over an open area does have sensible applications. And it's really a decent idea to learn how to accomplish it. It's also a good idea to see how it works in use.

As I mentioned in an early answer, taut silkspan can serve as the "mold" that makes spanning an opening with glass cloth in resin possible. I've done it and it works. I don't remember the exact products I used but the epoxy was very probably HobbyPoxyII. Epoxy structures are far more flexible and forgiving than polyester resin ones. That's why I used epoxy and it worked. I do remember that I concluded that my use of glass cloth gave less than the best result, that I should have used thicker if I stuck (pun intended) with glass, but that a less brittle cloth would have been better. There are cloths just like that available today.