Recently ordered some medium silk span from Joe Mader @ S & S Hobbies and some Randolph's non-taughtening nitrate dope from Aircraft Spruce & Specialty. this past weekend I attached the silk span with there non-taughtening dope, when dry after about 3 hours applied butyrate clear dope to finish shrinking the covering and it didn't happen......Silk-span is now very loose and sagging, wrinkles all over. where did I go wrong, I thought I remembered how to do it after 40 years, like riding a bike you never forget, but I guess I was wrong on this one.