Making Aluminum Powders
Descripción: a how to guide to making high grade aluminum powder for fireworks and pyrotechnics....
Make your own Aluminum powder! Aluminum powder is one of the key ingredients in many pyrotechnics, the most famous being flash powder. It ranges greatly in grades from flitter to a very fine flaky powder. The smaller and flatter the particle of aluminum, the more reactive it will be. German Black is the most common for flash powders and is normally 400 mesh and finer.
Image 1 – Final product
Materials: The materials required are simple and can be easily found or made. 1. Aluminum foil – Pretty much any brand will work, but the thinner the better!
Image 2 – Aluminum Foil
2. A blender - If you plan on making lots of this, you may want to pick up a used one from a thrift store.
Image 3 – Blender (no fruit needed)
3. A rock tumbler with 24 or more steel balls (between ” to 1” in diameter)
Image 4 –Double Ball Mill/rock tumbler
This can be found online, at places such as e-bay. Also check hobby shops and thrift stores. If you can’t get one, you can always make one by just by hooking a motor up to a barrel, and putting some ball bearings inside! If your stuck a more expensive alternative is to order a high quality one from http://www.unitednuclear.com/mills.htm or http://www.lortone.com/tumblers.html or use the detailed instructions at http://www.unitednuclear.com/ballmill.htm to build your own. 4. Stearin – Use no more than 5% of the weight of aluminum. Between 3% and 5% is the most common, although some do not use it at all. It is common in candle making, and if often found in craft stores. http://www.skylighter.com/ will carry it as well as e-bay. 5. Gloves – Pretty much anything that will cover your hands just in case you get a sharp piece of aluminum.
Process: Once you have all the materials, it is time to get started! The process is simple, but care still should be taken. First, rip off some strips of aluminum foil, and place them in the blender. Be careful not to overload the blender. I could fill mine loosely full (NEVER pack it in) with no problem.
Image 5 – Loaded Blender
Let the blender run until it has torn the foil into very small pieces. These can get sharp, so make sure you are using gloves or you might get a splinter! Next, empty the blender into your ball mill or rock tumbler, and repeat the process of blending the aluminum until you have enough for your barrel. Now add the steel balls into the barrel. Try to use at least two-dozen if you can. More will only speed up the process. I have used smaller lead balls, and it has worked well, but does take longer. Close up the ball mill, and let it run! I sometimes will set mine at an angle (between 15º and 25º) as this will aid in the tumbling action of the balls. Let this run for as long as necessary. This could be only a few days for a more grainy powder, or 2-3 weeks for an extremely fine and powerful powder. You should open the barrel up ever other day or so to let air in and allow the aluminum to build up it’s protective coating. You can use a mesh filter to sift out the desired size, so you can make multiple grades at once. If you let this run for its entire time, the powder should be at least just as fine as powdered sugar. Be sure to use gloves, as this will stain your hands with a light gray tint.
Increasing power If you used stearin in the process above, you can remove it by washing it with 99% isopropyl alcohol. Just toss the powdered aluminum into a jar, and pour in the alcohol until it is about half as deep as the powder. Stir it up well, and drain the alcohol using filter paper. This is normally done outside, because the alcohol vapor isn’t fun to breath, and it can explode very violently. Once completed, let the powder dry and your done!
Uses • • • • • • • • •
Catalysts for Chemical processing Used in Ceramics High-grade paint, print and toners Used in paint pigments, weather resistant paints, and heat resistant paints Used in pasts to conduct electricity Material surface treatment Rocket powders Aluminum alloys And MORE!
Additional Information Mesh 7000 6000 5000 4000 3500 2500 2000 1800 1600 1300 1100 1000 900 800 650 540 460
Micron 1.25 2.5 2.7 3.4 4.5 5 5.5 6.5 8 10 11 12 15 19 21 26 30
Other methods Please note that I have not personally tested all of these, although I will include them here for completeness.
Method 2: Materials • • • • •
Drill Press Aluminum rod Metal File (the larger flat type) Hack saw Sheet of paper or paper plate
Procedure Cut the aluminum rod into manageable pieces. Fix the rod into a drill press and turn it on. Hold a metal file at about a 45º angle and press it against the aluminum rod. Collect the powder on the paper plate or sheet of paper.
Process 3 Following the first process, except cover the blender blades with ethanol alcohol or vegetable oil. Filter out the aluminum and proceed as instructed above.
Process 4 Materials • • •
Aluminum foil Blowtorch Coffee grinder
Procedure Take a sheet of foil and heat it with the blowtorch. Allow to cool. Rip the foil into pieces so that it will fit into the coffee grinder Add the foil to the coffee grinder, and grind it at its finest setting. Remove the powder.
Word of Wisdom Aluminum powder has many uses, and is fairly safe to use. However, flash powders are very dangerous unless you know exactly what you are doing. In fact, making them is illegal in many places. Be sure to check with you local authorities. A rule of thumb is “Don’t be stupid, or you might die!”
Sources: Impact Firecrackers - John Donner 1996 http://www.theodoregray.com/PeriodicTable/Samples/013.13/s12s.JPG http://www.shroomery.org/images/26004/028502031-foil.jpg http://www.regcen.com/blenderrecall/blender.jpg http://i10.ebayimg.com/03/i/000/7a/0c/2b7a_1.JPG