For my high-school physics project, we're building boats using wood and paper. The only materials allowed are the aforementioned wood+paper, and wood glue and polyurethane coating. If I were to brush/paint the polyurethane onto the paper, do I have to worry about the paper getting too damp? Should I paint it on both sides of the paper at the same time, or should I coat one side first and then coat the inside after. Also, does the polyurethane make the paper stiff? I'm thinking I should get the paper glued onto the frame before painting, but I'm wondering if it's better to coat the paper first before applying it to the frame. Thanks!