Black Powder (Gunpowder) is the backbone of pyrotechnics. After all, it's Black
Powder that gives fireworks the smell we all love so much. Black Powder is the
main ingredient in a variety of firework and rocket formulas. You can easily
make your own high quality Black Powder with just a few chemicals and a Ball
Mill <mills.htm>.
Black Powder Basics
Black Powder is also known by a couple of other names. The most common, is Gun
Powder. Black powder is produced in large quantities commercially, and sold in
small 1 pound containers, mainly for use in antique Black Powder guns. It is
also normally sold in different granulations, and they indicate how fine the
Black Powder is granulated by how many "F's" they put on the container. Coarse
granulations are called "FG or FFG" (aka "1Fg" and "2Fg"). Finer granulations
are "FFFg and "FFFFg" (aka 3Fg and 4Fg). The more "F's", the finer the Black
Powder... and the finer the Black Powder is, the faster it burns. Small (fine)
granulations burn faster and are used in small bore guns, where larger (coarser)
granulations, are used for larger bore guns & cannons... and for launching
Aerial Shells out of mortars. Using a finer granulation for these jobs puts too
much strain on the gun (or shell or mortar) because the powder burns much faster
and creates a fast pressure increase that could damage whatever you're trying to
launch, or the gun/mortar itself. Coarser, granulated Black Powder that is used
in mortars to launch shells, or in Roman Candles to shoot out stars, is
sometimes called "Lift Powder". When Black Powder isn't granulated, and is in a
super fine powder state (similar to that of Talcum Powder) it is called "Meal
Powder". Just to confuse things even more, any granulated Black Powder is also
sometimes called "Grain Powder".
Smokeless Powder is not to be confused with Black Powder. It is actually
Nitrocellulose, and cannot be used in place of Black Powder.
Now, why they needed 5 names to describe one substance is beyond us, but just
keep in mind that Black Powder, Gun Powder, Lift Powder, Grain Powder, and Meal
Powder are basically all the same material. As far as fireworks are concerned,
Black Powder is used both in its finely powdered form (Meal Powder) for coating
starts and for mixing in other pyrotechnic formulas, and in its granulated form
(Lift Powder) for launching shells out of a mortar, or stars out of a Roman
Candle.
The formula for Black Powder is 75% Potassium Nitrate, 15% Charcoal, and 10%
Sulfur... and like all chemical formulas, it is measured by weight only.
However, you just can't mix these chemicals together and expect to have Black
Powder. The mixing process for Black Powder is just as important as the formula.
Black Powder *MUST* be made in a Ball Mill to work properly. A Ball Mill is a
rotating drum with dozens of lead balls inside. The 3 chemicals are loaded into
the Ball Mill, along with the lead balls, sealed shut and allowed to rotate for
anywhere between 1 hour and 24 hours. As the Ball Mill rotates, the lead balls
will crush the chemicals together, forcing some of the Potassium Nitrate into
the pores of the Charcoal and Sulfur. At the same time, the entire mass will be
reduced to a super fine powder. The longer the Ball Mill runs, the stronger the
Black Powder will be. A general rule of thumb for all pyrotechnic mixtures is "
the finer the powder is, the faster it will burn ". *ONLY* lead balls can be
used in a Ball Mill as they are completely non-sparking. *ONLY* Black Powder can
be mixed in a Ball Mill. Other pyrotechnic mixtures such as Flash Powder, etc.
*CAN NOT*, as they are too sensitive and will explode. Individual chemicals
however, can also be Ball Milled into a fine powder, but the mill must be
cleaned before this is done. If you are a do-it-yourself type of person, you can
build your own Ball Mill. For those that don't want to go through the hassle of
building one from scratch, Ball Mills, complete with hardened lead balls are
available from us. They can be found by Clicking Here <mills.htm>.
Once the mill has run for a while, it can be opened and the lead balls separated
from the fine Meal Powder. As we'll show you below, this Meal Powder can now be
used to make all the other forms of Black Powder for use in fireworks.
Black Powder vs. Flash Powder
A lot of people ask which is stronger, Black Powder or Flash Powder... or if
Black Powder can be used in Salutes (exploding fireworks). In short, there is no
comparison. Flash Powder is a high explosive, a shattering explosive. It
converts to a gas so fast, that objects near it, and containers that hold it
cannot move out of they way (or vent) fast enough to release this gas, so they
are destroyed into fragments. Black Powder is a low explosive, a heaving
explosive. It converts to gas much more slowly than Flash Powder, and generally
pushes things as opposed to fragmenting them. If Black Powder is used in a small
Salute like an M-80, it will just make a loud "pop", and push out the end plugs.
Flash Powder in an M-80 will make a loud explosion and fragment the tube into
small pieces. Flash Powder burns so much faster than Black Powder that in larger
Salutes, it doesn't even matter if you've got end plugs on the tube at all, it
will still detonate and fragment the Salute, even with 2 open ends. You can
*NEVER* substitute Flash Powder for Black Powder or vice-versa. If you were to
use Flash Powder to launch a shell out of a tube, or a bullet out of a gun, it
would barely move the shell or bullet, and completely destroy the mortar or gun,
most probably injuring the operator.
Manufacture
You will need 3 chemicals to make Black Powder, they are: Potassium Nitrate,
Sulfur and Charcoal. Stay away from very low grade materials like "Dusting
Sulfur" and Bar-B-Que Charcoal Briquettes. The Charcoal you use in a BBQ is not
pure Charcoal. It contains other materials and chemicals that are designed to
keep the material burning evenly and for a long time, but it will make lousy
Black Powder. If you use low quality chemicals, you will undoubtedly get low
quality Black Powder. All chemicals necessary to make Black Powder can be found
on our Chemical & Metals <chem.htm> supply page. The following is the standard
formula for Black Powder:
*Black Powder*
*Potassium Nitrate* *150 grams*
*Charcoal Powder* *30 grams*
*Sulfur* *20 grams*
Open the lid to your Ball Mill and add the following: 150 grams of Potassium
Nitrate, 30 grams of Charcoal Powder, and 20 grams of Sulfur ( if your lead
balls are not already in the tumbling barrel, go ahead and put them in now ).
Remember that *ONLY* lead balls can be used because they are completely non-
sparking. When complete, this will make 200 grams of Black Powder ( a little
under 1/2 pound ). You can make larger or smaller batches, just keep the
percentages of all the chemicals the same. You *MUST* use an accurate scale to
weigh your chemicals, preferably one that is accurate to 1/10th of a gram. If
you do not have access to an accurate scale, you can find some for sale on our
site here <scales.htm>.
With all 3 chemicals and the lead balls inside, put the lid on the tumbling
barrel and seal it, then set it in the Mill. Turn on your Ball Mill and let it
rotate for 2 to 4 hours. As the Ball Mill rotates, the lead balls will crush the
chemicals together and reduce them into a super fine powder. The longer you let
it grind, the stronger your Black Powder will be. Let the Ball Mill do its
grinding in an uninhabited area, not in a place like your bedroom. Although the
chance of accidental ignition is very remote, it is wise to put your mill in the
garage, or better yet, outside to do its work.
At the end of a couple of hours stop the mill. Lay out a sheet of paper (
newspaper will work fine ). Open the lid to the barrel, and dump the entire
contents ( lead balls and all ) into a spaghetti strainer over your sheet of
paper. The strainer will catch the lead balls and with a little shaking, all the
Black Powder will filter through onto your paper sheet. When Black Powder is in
a fine "dust-like" state like this, it is called "Meal Powder". The Meal Powder
you just made can now be used as-is in a variety of formulas and projects. By
adding a little water and Dextrin to it, you can easily make Black Match Fuse or
Quickmatch. See our section on making Black Match Fuse & Quickmatch
<experindex.htm>.
Lifting Powder
There are some applications where very fine Black Powder ( Meal Powder ) will
not work well. If you're going to use your Black Powder to launch shells out of
a mortar, or for small cannons, it will have to be granulated first. Black
Powder that is granulated and used for launching shells and salutes is called
"Lifting Powder". The procedure for making lifting powder is easy, but it
sometimes takes a few tries to get it perfect. Basically all we're going to do
is to add a little of a water soluble glue ( Dextrin ) to the Meal Powder, mix
it well, get it a little damp, and push it through the spaghetti strainer again.
This will produce small granules of Black Powder perfect for launching shells or
anything else. The whole trick to this is not to get the mixture too wet, or it
will become gooey and just turn into a big mess.
To convert your Meal Powder into Lifting Powder, take 100 grams of Meal Powder
and mix in 10 grams of dextrin. A good way to mix them is to put the mixture in
a plastic container with a snap-on lid and shake well. Pour the powder through
the spaghetti strainer again, this will break up any lumps in the dextrin.
Now place the Meal Powder/Dextrin mix back in your plastic container and add
just a little water. This is where experience really pays off. The idea here it
to get the mixture damp and not wet. What can be deceiving is that you're adding
water to a very fine powder, so it's going to take several minutes of mixing
just to get the powder to begin to absorb any water at all. Add just a little
water at a time, mixing thoroughly. As the powder begins to take in water, it
will turn a bit darker in color. You want the mixture to be damp enough to
where if you take a handful of it and squeeze it tightly, it will just begin
stick together. You do not want to get it too wet. If you do, it will not go
through the spaghetti strainer and will just clump up on the bottom, or not go
through the holes at all. If disaster strikes and you have added too much water,
you can always just add some plain Meal Powder to the mix to dry it out.
Just FYI, adding the water also increases the strength of the Black Powder by
allowing some of the Potassium Nitrate to dissolve and be absorbed into the
pores of the charcoal particles.
Once the mixture is damp, lay out another sheet of newspaper and dump the
mixture into the spaghetti strainer. Using a wooden or plastic spoon ( or your
hands if you don't mind getting messy ), rub the mixture through the screen
allowing the granules to fall onto the newspaper below. The Lift Powder you're
making will have to dry for a few days before it can be used, so make sure to
spread it around on the newspaper so it will dry more quickly.
If your mixture isn't all going through the screen, or is sticking on the
bottom, chances are it's too wet. Take the mixture out of the strainer and mix
in some plain dry Meal Powder and try again. If the mixture is going through
easily, but isn't really making granules, it might be a bit too dry. Take the
mixture out of the strainer and add a small amount of water, mix well and try
again.
