I much prefer using several #2 philips head screws when attaching windshields or canopies. Button heads would be even better, but I have found with #2's the allen wrench will quickly slip in them rendering them useless. Screws, however, only work when there is enough windshield meat to get a good grip on the plastic without distorting it. This is very scale-like on my Hangar 9 1/5 scale cub. Also RC-56 glue works quite well with wide windows.........it dries almost clear.