carter afb: fuel disappears?

I have the same issue. The carb was rebuilt by a professional, not me. The carb before the rebuild looked as though it had red mud in the dry carb. The guys in Texas who rebuilt may carb told me this was caused by ethanol used in gas today. My car is in the garage and never runs over 30 minutes as I am still restoring her. I'm not sure I buy the heat being the issue. I would like more info on where it may be leaking internally. I just don't understand. I had a friend who had a new Holly which would do the same thing. I wonder if the issue is the ethanol.
I am no professional, and am certainly not discounting any of your ideas, Just seeking an answer to a problem. I had no idea the problem was as widespread as it seems to be. Maybe changing to a non-ethanol fuel would help. Someone local who builds and races drag car said he uses a fuel stabilizer in his fuel to help with the problem, maybe a thought.