I applied polyspan using Baslaloc, a water based heat seal adhesive. Is that available? You apply a thin layer to the wood surface and after it dries, apply the polyspan with a covering iron, just like monocoat. After shrinking, I then sealed the polyspan with Minwax Polycrylic. Worked pretty well. Also, can you get some of the SLC film? It's a thin mylar film. You cover just the open bays with it and then cover the whole wing with silkspan attached with polycrylic. Just as strong as polyspan.