The way I seal balsa wood cranks is as follows, 1 coat of super glue then lightly sand, 1 coat of flex coat rob builder's epoxy, scuff with 320 grit, prime, paint, and clear coat with flex coat ultra v high build. I have foiled baits over 10yrs old that have held up. I've been building since 2002 and never had a issue with my seal coat peeling off of foil.