I have a builder who builds my Carden airplanes for me. He insists that polyurethane (Gorrilla glue) is the only way to go. All I know is the wings sure are smooth when he is done. Dalton Aviation uses epoxy to do his. He says & I quote, "It takes 7 oz. of glue to glue up a set of 42% wings no matter what glue you use". The only airplane kit I ever built that had sheeted foam wings, I used Sorghum to apply the sheeting. I guess whatever floats your boat, if done right, will do a good job. I do know that gorrilla glue works very well though & is easy to work with.