Originally Posted by Botnst

You’re on the right track. “Thermite” is a mixture of aluminum powder and iron oxide powder. Iron oxide is rust. When thermite ignites it burns quickly at extremely high temperatures. It will burn through thick steel, for example. And fuggetabout extinguishing it. Pure, unoxidized powdered aluminum alone is dangerous. Aluminum is extremely thirsty for oxygen but in the absence of oxygen is pretty benign. Almost all aluminum we see in our daily lives has a microscopic oxidized layer.

I prefer not to get on a BATF watch list, but a search for aluminum powder will get you lots of how-to projects, some of which are a free ticket to federal penitentiary.