Gallery Glass (and other liquid glass products) can be rather difficult to apply on windows with large spaces between the mullions. I was working on a C&O standard station kit the other day, and the kit instructions said that you needed to apply clear styrene to the back of the bay windows and leave a small "flange" that would be used for holding the casting in the window opening. I decided to attach the styrene to the back of the window with Gallery Glass. After that was thoroughly cured, I filled the spaces between the mullions on the front side, with 2 thin layers of GG. When this had fully cured and the GG had returned to clear, I started to cut back the styrene to make the small flanges, and here is where the "accident" took place - at the first flexing of the styrene, it "popped off" the back of the window leaving the GG fully intact on the front of the window! I repeated this on the other 2 bay windows and cemented them into the openings. This is a great way to use GG, since it doesn't require special handling while the "film" is curing - just leave the windows on a flat surface and pour in thin layers!