Sand the wing down good with 300 or better. apply two cotes on nitrate dope to balsa. this is a base for attaching silkspan. now wet silkspan and sponge dry it, then lay on wing. Make sure it is square and no wrinkles. now, with a small brush, apply nitrate dope on top of silkspan where it touches balsa, this dope will penitrate silkspan and adhear to first two cotes of dope on balsa. Repeat after this cote is dry. now you can fully cote silkspan with one or two coats of nitrate or butrate dope . the silkspan will shrink and become very tight. I have used butrate dope to adhear the silkspan down to the balsa and it worked ok, but the " experts " sy use nitrate for adhearing nd the first two cotes.
Danger !!!!!!!!! nitrate dope is very combustable, only use it outside, away from any and all sparts and static electricity !!!!!!