Any type of porous metal (zinc, aluminum, etc) will suffer corrosion when exposed to E85 ethanol.
The solution is to plate the metal. Electroless nickel plating is what our company uses on machined aluminum castings.
Similarly, E85 attacks rubber parts so specialized synthetic rubber compounds must be used for o-rings, gaskets, etc.
Thanks! I don't think E85 is too hard to avoid right now. I made long distance trips and it seems that all the gasoline in most of the places I went contained at least 10% ethanol. That coupled with the lower gas mileage of ethanol mean I probably won't use it too often. I probably will use the 10% now and then during the winter to get rid of any water in the tank.