Make Black Powder - Hand Mixed Method
Hand Mixed Pulverone Black Powder Used to Burst Shells
Photo © Old Glory Powder Company
It's called many things:
- handmade black powder
- screened powder
- green powder
- green mix
- rough powder
And black powder is, of course, also called "BP" and "gunpowder."
This project originally appeared as Chapter 7 in Skylighter's fireworks-making course, Turbo Pyro, which Ned Gorski wrote. In Turbo Pyro, we refer to this powder as "base mix." Turbo Pyro's base mix is simply hand-mixed black powder. I have adapted Chapter 7 to become this standalone project on making hand mixed black powder.
Black powder comes in many forms, and some is more powerful than others. Hand made black powder is generally the least powerful. Now, lest you think that hand mixed black powder is too weak and unworthy in some way, I want to share a little story with you.
When I visited the fine fireworks company, Pyrotechnico, near New Castle, Pennsylvania in 1996, I had a chance to watch two guys making traditional Italian canister shells. In the little shed where they were working together were boxes of a greenish-black, lava-looking powder they were using as burst powder for their shells. I was green, too, and didn't know what it was.
When I picked up some in my fingers and looked at it curiously, one of them simply said, "Pulverone. Green powder."
Now I knew what it was, but I hadn't ever seen it before. They were constructing their shells using commercial Goex 2FA black powder for lift powder and using pulverone to burst their shells.
"Why green powder?"
"Because is cheap," he explained.
Later at a PGI Convention, I asked Jim Freeman why he was using pulverone--to me a weak powder--to burst his prize-winning, Italian-style shells. Now, Jim makes some BIG shells. Some of them 8 inches in diameter and 3 and 4 feet long.
"I just want to break the shell, Harry. I don't want to kill it," Jim replied.
"But isn't the powder too weak to do that," I wanted to know?
"No, not once I paste and string the shell the way I do. All that compressing from stringing and pasting the shell is what gives pulverone all the power it needs to do its job."
Strung and Pasted Italian Style Shells Containing Hand Mixed Black Powder for Burst
Photo © Old Glory Powder Company
Thanks, Jim, for that early lesson.
Now, let me be clear. I consistently recommend to anyone making fireworks today that they get a ball mill, and learn to make black powder using it. Period. It is an absolutely necessary tool for every serious fireworker. You cannot go far without one.
But if you don't yet have a ball mill, that's the main reason we created this project--to show you how to make black powder by hand, without a ball mill. And green, hand-mixed, pulverone black powder definitely has a place in fireworks, whether you own a mill or not.
Hand Mixed Black Powder - Pros and Cons
First, green powder is a good starting point if you're new. That's precisely why handmade powder is used in Turbo Pyro--a course specifically designed for you to learn to make fireworks.
It's quick and easy to make. You need 3 or 4 chemicals and a couple of screens to make it. It dries fast. And there's very little learning curve.
"Is cheap," especially if you're just getting started. You don't have to invest in a ball mill and the increasingly expensive grinding media for it--usually hardened lead balls, brass, or bronze. The chemicals cost the same either way, but you won't have to make a $200-$300 front end investment.
It works in many fireworks. The Turbo Pyro course shows you how to make 10 different fireworks--mostly 3/8-inch devices which all work just fine using hand mixed powder. It is a myth that the "best" black powder is the fastest or most powerful. Often we don't want the most powerful. For instance, even some larger rockets can use hand mixed BP. Green powder coated rice hulls and coarse grained pulverone are routinely used to break aerial shells. It can be used in fountains, star comp's, small drivers and spinners, and in star primes. And even coarse pulverone originally made for burst powder can be used to lift shells in a pinch.
You don't need a license to buy it. Commercial 2FA and Meal Powder, the two most common grades of black powder used in fireworks, both require an ATF license for you to purchase. But no license is needed if you make the stuff yourself.
Really, only one: lower power.
Green powder is not as powerful as milled and corned black powders. Nor are there really any practical ways to "hop it up."
So, while you can definitely get off to a great start making (generally smaller) fireworks using hand mixed powder, as you move up in fireworks size, you're eventually going to need more powerful black powder.
While we don't cover it here, folks sometimes ask if the "CIA" wet-mixed black powder isn't more powerful, or good enough for bigger fireworks. (This is another method not requiring a ball mill.) And the simple answer is basically "no."
Think of weaker powders this way: you can use them for all sorts of things. But the bigger the job, the more green powder you have to use. It just takes a lot more green powder to lift a 6-inch shell than it does ball milled powder. Eventually you would need to use so much hand mixed BP, that using ball milled powder saves you enough money on chemicals that it become the most economical way to work.
Does that make sense to you?
So regardless of whether you have a ball mill or not, this project shows you how to make great hand mixed black powder to use for all sorts of things.
What Is "Hand Mixed" Black Powder?
by Ned GorskiRegardless of how they are made, all black powders contain the same three components: potassium nitrate, charcoal, and sulfur. If any one of these chemicals is missing, it is not black powder. (It might even be black colored powder, but it won't be true black powder.)
Mostly this type of powder is used as is. Often other chemicals are added or mixed to serve as the basis for different formulations (like stars, rocket fuel, fountain mix, etc.).
WARNING: You're about to make one of the most common, yet powerful, pyrotechnic compositions used in fireworks. You should have a healthy respect for handling it:
- minimize the exposure of this composition to any possible ignition source whenever possible.
- reduce the amount of it you are using or have in any one, open container
- store the mixture safely away from where you are working and any possible source of ignition.
Watch what happens when just one teaspoonful of hand mixed black powder is laid out in a line 8-inches long and ignited.
One Teaspoonful of Hand Mixed Black-Powder Being Ignited
You can see by its speed that if you are close to a large quantity of this powder when it ignites, you will not have time to escape the fireball. Advance preparation is the only way to avoid serious mishaps when working with energetic compositions. You will never be able to outrun an accidental pyrotechnic ignition.
How Much Black Powder Should You Make?My advice is to start with a fairly small batch your first time. One of the most basic safety practices in fireworking is to work with the least amount of mixed chemicals whenever possible.
You will also find--the hard way I suspect--that if you will first make one or two small test batches of everything new, that you'll not only be safer, you'll save yourself a bundle of money. Sometimes, there is simply no way to correct or recover a large batch of powder where you made a mistake. Throwing it away or having to destroy it can be costly.
You can adapt the table below to any quantity you want to make. Here's what you need to make a 24 ounce batch of hand mixed black powder.
You will need to weigh the following quantity of each chemical:
|Chemical||Parts/%||24 Ounces||680 Grams|
|Potassium nitrate||75||18 ounces||510 grams|
|Airfloat charcoal||15||3.6 ounces||102 grams|
|Sulfur||10||2.4 ounces||68 grams|
The proportions are critical. Get them wrong and your powder will not work. Use a good digital scale. You cannot make black powder by measuring volume instead of weight. You have to use a scale.
Milling the Potassium Nitrate and SulfurBefore mixing, you first need to grind or mill each of the three components very finely, each one by itself. Do not mix them until after they have been finely milled or ground.
Here's a simple method for grinding individual chemicals very fine by using a small, cheap blade-type coffee mill you can find at WalMart for about $15.
Never ever grind mixtures of chemicals in a coffee mill or blender, because they are likely to ignite or explode.
Typically, a small coffee mill can efficiently grind about 3 ounces of the potassium nitrate at a time, and 1.2 ounces of the sulfur at a time. It only takes 10-20 seconds for each batch. So to make a 24-ounce batch, you should mill six 3-ounce batches of the potassium nitrate and two 1.2-ounce batches of sulfur. Remember, you don't need to mill airfloat charcoal. You would need to grind any charcoal that's coarser than airfloat.
Make sure they are fluffy-fine. You cannot grind them too fine. The finer the particles, the better your black powder will work. Store these individual milled chemicals in their own plastic baggies, segregated from the unmilled chemicals.
Grinding Individual Chemicals with a Blade-Type Coffee Mill
Note: Small inexpensive coffee mills like those from Walmart can overheat if you run them too long. Once they overheat and stop working, they won't work again. Use short 5-10 second pulses, shake the mill while you grind, and let the mill cool down before milling any more.
WARNING: Do not confuse a blade-type coffee mill with a ball mill. The two types of mills work very differently. NEVER mill mixed chemicals together in a blade mill. Its violently spinning, hard steel blades will likely cause mixed black powder chemicals to ignite or explode. But in a ball mill the relatively gentle tumbling action of mixed black powder chemicals and lead balls is far less dangerous. So, while a blade mill is great for quickly milling one chemical, it is extremely dangerous to use for mixed chemicals.
Here is a short article on how to mill powder using a coffee grinder. If you are in any way confused or not clear about this, get in touch with us before proceeding.
Mixing Black PowderYou should now have a tub of 3.6 ounces of airfloat charcoal, 18 ounces of milled potassium nitrate, and 2.4 ounces of milled sulfur. You'll use these three chemicals to make the 24 ounces of black powder. But it it's too cumbersome working with batches that large, you can first make three 8-ounce batches.
8-Ounce Batch of Hand Mixed Black Powder
|Chemical||Percentage||8 Ounces||227 Grams|
|Potassium nitrate||0.75||6 ounces||170 grams|
|Airfloat charcoal||0.15||1.2 ounces||34 grams|
|Sulfur||0.10||0.8 ounces||23 grams|
|Total||1.00||8 ounces||227 grams|
Weigh out the individual chemicals for an 8-ounce batch into their own paper cups. Then dump them into a plastic mixing tub. With the lid on tight, shake the chemicals to mix them together, holding the lid down while you do.
Then open the tub, and pass the mixture through a Skylighter 40-mesh framed screen or 40-mesh colander into another empty tub. Work the composition through the screen with your gloved hand.
Cap that second tub and shake the contents again. Repeat the shaking and screening process three times to ensure the chemicals are completely mixed.
Note: Mixing and screening this chemical mixture is a dirty process. It's best done outdoors wearing a dust mask, long sleeves and gloves. This is now a very flammable, potentially explosive composition and needs to be treated with respect, keeping it away from all sources of sparks and flames.
Lifesaving Safety Tip: Whenever working with flammable pyrotechnic mixtures, wear a long-sleeve cotton shirt, long cotton pants, and eye protection. An accidental ignition of a normal working quantity of black powder, star composition, or some other fireworks mix will create an instantaneous fireball large enough to completely envelop you in it. You can survive being inside a large fireball if most of your skin is covered. And cotton will protect you, usually without catching fire itself--unlike synthetics, which you should never wear when working with flammable mixtures. Synthetics will burn, melt, and fuse into your skin. Remember: cover as much skin as possible with 100% cotton cloth. Cotton vs. synthetics can literally mean the difference between an unpleasant day or your last one.
Weighing and Screen-Mixing Chemicals for Black Powder
Dampening, Granulating, and Drying Black PowderAs you will see, the BP you have just mixed is extremely dusty and dirty to work with. Now you may want to keep some of this dusty stuff, because it is basically the same particle size as Meal-D black powder. And you need Meal-D for various things such as star primes.
But you can cut down on the dust and cleanup by granulating the rest of your powder. Granulating also helps to "carry" metal powders in spark-producing comp's for fountains, comets, stars, and rocket fuel.
Minimize dust contamination by doing this outdoors and wearing gloves. Do it on a day that's not too windy. Spray water into the mixed black powder composition, and work the water into the powder with your hands.
Spray one ounce of water (either a fluid ounce by volume or an ounce by weight--they're both the same) into the 8-ounce batch of powder. Work it in with your hands. Then press the dampened composition through a 20-mesh screen or coarse mesh kitchen colander.
Dampening and Screening the Powder
Spread the dampened composition out evenly on a paper lined tray. Place in a safe, warm place to dry, ideally outdoors. In a warm and lightly breezy location the mixture will be dry in a few hours. But, if there is too much wind, the paper and mix will fly off your tray, ruining your hard work.
Drying Black Powder on a Paper-Lined Tray
After it dries, work the powder through the 20-mesh screen one more time to break up clumps. Then put it into a sealed plastic container. Store this container safely away from any source of heat, sparks, or fire.
This granulated BP will just hold together. The grains are not hard. It's now ready to be used in many projects: fountains, wheels, rockets, and some special effects.
Making Large Grained Hand-Mixed Black PowderBut suppose you want to use your hand-mixed black powder for burst powder in larger shells, or even for emergency lift powder for shells.
This is how my Italian friends made their "pulverone" burst powder.
First, you'll need a screen with holes the size of the powder granules you want to end up with. Since 2FA black powder, frequently used for lift, and some burst, contains mostly about ¼-inch grains, you should look for screen the same size. Skylighter's 4 mesh framed stainless steel wire screens are perfect, and will last many years. Although it's not rust-proof, you can also use ¼-inch galvanized screen found in many hardware stores and make your own wooden frames.
You'll also need to add dextrin to your black powder. Dextrin, when wetted, will serve as a glue to hold your large black powder granules together and make them hard.
Just repeat the process above of dampening, granulating, and drying, but first add +5% dextrin to your black powder before you start to mix it.
For example, if you are starting with 100 grams of black powder, add 5 additional grams of dry dextrin powder to the mix before you start to screen the chemicals together. Blade mill the dextrin first if it has gotten clumpy.
Do everything else in the process the same, except substitute a 4 mesh screen for the 20 mesh screen.
That's it--2FA sized pulverone that you can use for burst powder.