RE: E85 might be E70 ???
If this info has already been posted forgive me as I kind of skimmed through the posts.
Castor oil will not stay in suspension in gasoline. Just make sure you shake the fuel jug before you add to you airplane. It should be good until you fly it out, if you fly within five minutes or so. Now with that said maybe the ethanol will work as a mixing agent keeping the castor in suspension???