Magnesium is hazardous when wet and can decompose in the presence of ammonium perchlorate without the bichromate protection. Potassium bichromate (dichromate) is very poisonous and a suspected carcinogen. Handle with care.
Magnesium must be coated with potassium bichromate (dichromate) as follows: 1) heat 1000g of magnesium spread out on pie pan for one hour in an air oven set at 210 deg F. 2) dissolve 50g of potassium bichromate in 10oz (300cc) of hot water. 3) Outdoors, add the bichromate solution to the warm magnesium and incorporate by hand using gloves, arm protection and a respirator. 4) spread out on a sheet of newspaper to dry. 5) screen before fully dry, then screen again after completely dry. The 5 parts potassium dichromate in the formula is best ballmilled with the 50 parts ammonium perchlorate to reduce the dichromate to fine powder while also maknig intimate contact with the AP. Avoid brass or bronze media when milling AP, due to the presence of copper which can make AP more sensitive. A clean jar and media is a must. For cut stars, dampen 25% by weight with 10% NC lacquer in Acetone. Stars must be primed with special strobe ignitor (see under primes) before the final BP prime. Strobe frequency is about 3.5 hertz, which can be increased by using finer magnesium.
Author: Takeo Shimizu