I am considering building an 'aluminizer'... but I can't find a lot of detail in how they work. I know that they use a vacuum chamber, and then elements heat up and evaporate aluminum which then deposits on the glass surface. But how hot do the elements have to be? and can it be any old piece of aluminum, or does it have to be a certain thickness/size/shape? Are the aluminum and hot elements above the glass and the Al travels down to deposit on the glass, or its it the other way around?

The aluminum condenses on the glass, like water steam on a cool surface.