I struggle with this mostly during the white fly hatch on the Susquehanna. The smallmouth bass really put a beating on dry flies. In my opinion floatant is only good on a perfectly dry fly, after it gets wet the dust will help but mostly I just squeeze the moisture out with my shirt sleeve and blow it dry, false casting can help, then it floats a little while til another bass destroys it.
There is a patch made from from a material named amadou that has high praise, it's over $25 for a small patch though. I read that a piece of Sham-Wow works also.
Definitely put floatant on the tippet and leader. I used to have shark skin line on my 6wt. and after a couple years it began to crack and sink, I remember coating it with floatant as a temp fix, lol, desperate times, it worked for a short time.
I tried pre-treating some sulphurs last year but that was mostly a bust, lasted only a short while.
I really wish I could find an unsinkable white fly, friends of mine have tried creating them with some foam with mixed results, they've even tried using glow in the dark material so we could see takes after dark. Melvin is pretty much spot on with the use of foam. I wonder if a small piece of balsa or cork would work as a body, the rest of the fly isn't as important as the smallies are not so picky, usually, lol.
