General Information | Low Order / Burst
AKA: Gun powder (in some circles), BP, "powder".
Appears: Black or very dark grey powder.
Formula: KNO3 + S + C
Stability: Moderately Stable
Sensitivity: Spark, Flame
Solubility: Partial solubility in water.
Generally readily available. Brands include:
Goex Authentic Rifle Propellant
Hobby Shops, Department Stores
Black powder (or a reasonable facsimile thereof)
is used as the fuel in model rocket engines.
Preparation of black powder is a heavily discussed topic,
and there are quite a few methods and revisions of methods concerning the
preparation of the stuff. For the most part, preparation methods fall under
one of two schools of thought: The milling method and the precipitation
method. The milling method will be discussed here. In order to carry out
this process, one will need a ball mill and optionally a press.
After measuring the ingredients they are mixed together
and loaded into the ball mill. The total amount of powder you can mill
at one time is dependent on the size and power of your mill, so no specific
loads will be given here. As a general rule, the mill should be filled
2/3 of the way once the material to be milled and the milling media (balls)
Mill the ingredients for about six hours, or until
you are confident that the mixture is milled to the finest power possible.
At this juncture the powder can be used as-is, since it is quite intimately
mixed, but others may desire to press and corn the powder to increase performance.
If this is the case, the milled powder is loaded into the press and compressed
to 1.7 grams per cubic centimeter (which can be easily calculated by dividing
the total weight of your ingredients to the volume of the press after you've
cranked it), then crushed into the desired grain size.
Regardless of how you prepare it, black powder will
ignite with a spark or flame, burning quickly with an orange flame and
producing a fairly large quantity of grey smoke in the process. The burning
speed of the powder will depend on how well it is mixed, the amount of
moisture present, and the size of the grains (if it has been pressed and
corned). Poorly prepared black powder will burn slowly or not at all. If
your black powder burns slowly and produces molten balls of potassium nitrate
as it combusts (called pearls) it is a sign that your powder either has
too much potassium nitrate or the nitrate is not mixed with the powder
Black powder has a multitude of uses, including
burst charges, primes, pyrotechnic boosters, fuses, and igniters.
Spark and flame sensitive. Avoid these dangers, and
Hygroscopic. Keep sealed during storage.