I'm building a scratch 8' Otter from plans blown up from a 6' UH kit. This is a float plane only. I'm going to build fuse from pink foam and am considering spray or roller coating with Styrospray1000 coating. Has anyone used this material or another brand to seal foam or balsa for a fuselage? If so what will I need to know. I'd like to coat the entire plane and floats with a light sealing coat and then paint. I am concerned about the weight!