You can also try a low temp covering like Ultracoat.

As for gluing skins onto a frame, there's the iron on technique which works quite well. Apply an even coat of alphatic resin or PVA glue (carpenters glue) to all the ribs and spars. Apply an even coat to the skins where it will meet the ribs and spars. Let the glue dry BEFORE assembly (about an hour). Place the skin into position and use a covering iron to "reactivate" the glue. Once the glue is heated, the bond is almost instant like contact cement.

Scott