Aluminum Alloys

i was thinking of melting aluminum and making aluminum plates but what would i use as a mold? could i use a cookie sheet(with sides lol)or would i have to make a mold?

i have been thinking about using aluminum for a bit and i was wondering how i could build a melting furnace for melting scrap aluminum. i was also wondering could u melt aluminum cans(soda cans, etc.) to make aluminum bars? We get a lot of soda cans every week, so i think we would have enough to make some small sized bars. also how much would it be to make a melting furnace for aluminum? i would like to use propane or possibly electric.

I'm toying with the idea of fabricating my own copper range hood. I'll say up-front that I have no (zero-zilch-none) metalworking experience. I am a fairly skilled woodworker, for whatever that's worth, and I'd say i have good mechanical ability and a high capacity to learn. Having said all of that, I admit again that I have no idea where to start, but I view this as an opportunity to expand my skills. So, am i out of my mind? Please let me know if I'm nuts to tackle this. If not, please point me in the right direction (tips / advice / resources). And yes, my wife thinks I'm nuts. Thanks! Rob