I am building an Alaskan recovery kayak using the SK article as a guide.I plan on buying Cordura nylon ~7oz. for the skin.I noticed that the fabric was marked "waterproof"; the salesman at the discount store didn't know what that meant. Question#1 Can this "waterproof" fabric be painted? #2 Can a water-based paint designed for painting inflatables be used? (West Marine sells this paint in gray only.)