Types of Aluminium:

Dark (Pyro) Aluminium: It is a very fine powder and dark grey in colour. Nominal mesh size is 200 but it contains particles of 2µ. There is a wide variety of uses for dark aluminium, for example: flash powders, star compositons, fountains, waterfalls, torches, flares, etc. For all this purposes it is generally used as a fuel. Many powders sold as "dark" aren´t really dark aluminium but the atomized type (often 63µ) and although the color of the former may vary it has to be dark grey and not light grey or even whitish grey (some of the best dark aluminium comes from Eckart Germany and this powder is nearly black in color = German Dark). Under the microscope it´s possible to identify atomized and dark powders quite well: the former are spherical in shape while the latter are irregular and angular. Dark alu is generally the most expensive of all the alu powders.

Atomized Aluminuim: It is increasingly used in fireworks although there are only limited uses for it (this is because spherical or spindle shaped particles are more difficult to ignite than a flake). In practice no material coarser than 120 mesh can be used and commercial atomized powders are generally 300+ mesh and light grey to grey in colour. It is needed for glitter effects and other special stars, to give an example only.

Flake Aluminium: There are mainly three different types of flake alu (all silver in colour). The first is "bronze" also known as paint grade aluminium. This fluffy powder is used for making paint and the particle size is very fine (sometimes less than 2µ). Paint aluminium generally contains grease or stearine (the content varies from one to four percent by weight) which decreases its reactivity. Nevertheless aluminium bronze is easily obtained from an artist supply and produces quite good silver effects. It can be used wherever "bright" aluminium is mentioned in a composition. Generally it´s a dirty business to work with fatty aluminium. It only passes the mesh when accompanied by another material. The second flake aluminium is the real "bright" or "brilliant" powder we can subsitute with bronze for most purposes. Bright alu usually passes 120 mesh (nominal mesh size 120-200) and like "bronze" is very fluffy and leafing mass. The main difference to the latter is that brilliant powders contain less grease/stearine (0,5% by weight max) or are coated with another material which means that they aren´t as fatty to handle as bronze grades. They are used as a fuel for many purposes and to obtain silver effects. The third flake grade is called "flitter" which means flake powders of a larger mesh size than bright aluminium. It is sold as "fine", "middle" and "coarse" flake/flitter. Some people think that using flitter larger mesh variations are allowed. Sometimes this might be true but corresponding to the correct mesh size often makes the critical difference. As a rule of thumb fine flitter is: 80-120 mesh, middle flitter is: 30-80 mesh and coarse flitter (=coarse flake) is 10-30 mesh.

Aluminium Particle Types: