I am in the process of covering the wing on my SS7 and I see that the bottom side is slightly concave. I also noticed in Tom Waid's build Log that he had the fabric pop loose from a rib at a concave place while shrinking the fabric. So I am assuming that the covering process, at least for the bottom surface, should follow Appendix C in the Polyfiber book where it gives the process for covering an undercambered wing. The Kitfox build manual only says to precoat the ribs with Polytak cement. How did you guys treat this?

Jim