Ilook at the Hog Bipe insturctions and the sides are lite ply and Iheard that the same thing is on the Hog. I just built a glider and it had Lite Ply sides on it too. Idid build it, but also used it for a pattern to build one out of balsa. Ithink lite ply is just cheap and they use what ever is cheaper. it sure can't be for strength. I don't see where you need anywhere near that kind of strength on the sides. I always use balsa even if they supply lite ply. Ijust built the glider to see what the weight came out to be. It's heavy and because Ididn't have the balsa at the time and was in a hurry Iwent and built it to the plans and the wood supplied.

Ed