Step 2: Mix
Always mix chemicals by their weight. The ratio for the flash powder formula is:
Aluminum powder 30%
Potassium perchlorate 70%
Before you start measuring out the chemicals, it is good practice to neutralize your environment by spraying some anti-static spray around where you will be working. It can be made easily by mixing 1 part fabric softener to 9 parts water and putting it in a spray bottle.
Using the ratio, measure out how much aluminum powder you will use and put it in a plastic ziplock bag (spray the bag with anti-static also) Then measure out how much potassium perchlorate you will use and put it in the bag. Seal the bag and gently shake it around until the chemicals are evenly mixed.
Once the flash powder is mixed do not seal it in any form of container, this will lessen the risk of an accidental explosion.
Do not store the flash powder only make what you are going to use.