I did electrolysis by adding aluminum to the ends of the wire. I waited about 2 hours, and then I filtered the water. After it dried, I was left with powder. It\'s gray.It that aluminum powder or something else? I\'m making thermite, if its not aluminum powder will it still work?Kinda sorta, the problem with this is that all you did was made aluminium oxide or hydroxide, when you electrolyzed the aluminium you also electrolyzed a bit of water with it, which added a hydroxyl group to the aluminum, which may have dropped a hydrogen when you dried it. If you could find an aluminium compound that is water soluble (DAMNED HARD to find) you could electrolyze it in water to get aluminium dust in the water, but that isnt very reliable or economical, the best thing for you to do is to get a ball mill or rock tumbler, add aluminium fold and about half full of regular marbles, let it run for 3 or so weeks. You need it really fine!Other related question