How to Make Electric Matches

In the next few weeks we will show you some ways to plan and set up a consumer fireworks display, including tips on firing portions of the show electrically. We’ll discuss electric firing systems and electric matches.

Why would one want to fire some or all of a fireworks display electrically? First, it’s safer to fire a device electrically than it is to light it by hand, especially if the item is in the middle of a field full of similar fireworks. Electric firing also enables the display operator to sit back and enjoy the show along with the rest of the crowd. Precision timing is also enhanced by shooting with a firing system.

Many of us are familiar with small firing panels and electric matches from our early days of experimenting with model rockets, since small versions of the igniters are used to remotely fire those motors.

Quite a long time ago I made some electric matches using a kit which instructed me to just dip the bare ends of some wire into a composition that was dampened with some acetone, and then again into a finish coating.

I didn’t have much luck with that system, and ended up firing the electric matches with a high-voltage system just to get them to ignite. I was disappointed. Ever since then I’ve had access to commercially made electric igniters, since I am an ATF licensed display operator.

But, you may not have access to commercial electric matches: They are a regulated explosive and require an ATF license to purchase them. But making them yourself is legal and does not require an ATF license.

Now and then my curiosity has been piqued when I’ve seen some of the various methods for making electric matches. I’ve seen the match heads that you solder wires onto, and then dip into various compositions. Also, there are ematch blanks, which have wires already soldered onto match heads, ready for the application of the pyrogens (combustible compositions).

So, I figured that the only way I could credibly discuss these homemade electric matches was to play a bit with them myself. Fortunately, I just recently spent some time in Virginia at the Skylighter facility, and was able to pick the brain of Brian Paonessa, who is one of the main Skylighter pyro experts, and who has experimented extensively with homemade electric igniters.

I assembled a kit of materials to bring home and play with.

The electric matches I’ll be discussing have five basic parts:

Insulated, two-conductor, wire “leads” connected to the match head. The insulation is stripped back for about an inch at the opposite ends of the wires from the match head. These bare wire-ends are twisted together (shunted) to prevent a current from passing from one end of the wire, through the match head, and out the other end, accidentally firing the electric match.

The match head consists of a small chip of circuit board, which has a metallic conducting surface on both sides, separated by an insulating material.

An extremely thin (48-51 gauge) strand of nickel-chromium (nichrome) bridge wire is soldered to the chip, with one end soldered to each side, and with the exposed wire spanning the end of the chip and crossing over the insulated core.

Pyrogen: The tip of the chip, containing the nichrome wire, is dipped in pyrotechnic composition, in one or more coats, and then into a hard, smooth finish layer.

Finally, a plastic, protective-shroud covers the match head to prevent accidental ignition of the sensitive pyrogen as a result of friction or mechanical shock.

When enough current is passed through the ematch leads, the nichrome wire heats up and ignites the pyrogen, producing a flame, which will ignite the flammable materials that the ematch is in contact with. This happens in milliseconds. When it does, the nichrome wire burns through and is consumed, breaking the electric circuit.

Note: If one can obtain circuit board blanks with conductive coating on both sides, Skylighter sells the thin nichrome wire so that heads can be cut to size and the nichrome soldered onto them. This is a very painstaking process. In the back of my mind, a future project would be to buy some copper-foil-tape from a stained-glass supply store, press the foil tape to both sides of a piece of cereal-box cardboard, and cut match heads out of it. Soldering the nichrome wire onto those heads would produce homemade match heads.

If you go to the Skylighter (http://www.Skylighter.com)
website, click on the Ignition Supplies
under the Order Products heading, and scroll down to item number GN5030, Electric Match Heads, you can “click here” to see the instructions for this item. They detail the soldering of the wires onto the match heads, and then the coating of the match head with the various layers of homemade pyrogens.

At this stage, I like to work with short lengths of wire, so I cut about a foot of shooting wire, strip an inch of insulation from the wires at one end and lightly twist them together to shunt them, and strip about a quarter inch of insulation from the wires at the other end.

Soldering the wires onto the match head is easier if you “tin” the wires by coating them lightly with solder first. Then, the tinned ends are pushed together until they are just barely separated, and the match head is slid between the wires and gently soldered in place per the instructions.

A small “pencil” soldering iron and rosin-core solder come in handy for this process. You want to be careful to avoid overheating the match head during the soldering.

Note: The ematch heads do not come with plastic protective shrouds, which many of us consider to be an essential safety component of ematches. Rubber surgical tubing, of the appropriate inner diameter, can be cut to 1″ lengths to use as protective shrouds on finished electric matches.

Whether I’ve purchased the pre-soldered ematch blanks, or have made them by soldering wires onto the match heads, I like to test the blank at this point. I do that two ways. I use Skylighter’s Ematch Tester
(GN5005) and make sure it lights up when the untwisted leads of the ematch are pressed to the sides of the tester.

I also use a Radio Shack Digital Multimeter to check the resistance of the match. All of the matches I’ve been working with have a resistance of 1.1 to 1.2 ohms. If the reading is significantly different, I discard the ematch blank.

This testing insures that the nichrome bridge wire is in place correctly, and is intact. It also proves that there is no excess solder bridging the two conductive surfaces on the chip, or between the wires.

Note: It is important to use a digital meter to check electric matches. Test it on a finished electric match first in a safe location. It has to have been proven to use a small enough amount of current that it will not fire ematches. My understanding is that the test current in analog meters with needle-readouts will accidentally fire ematches if that type of meter is used to test them.

Now, with the tested ematch blanks, we have assemblies that are ready to have their ends coated with pyrotechnic compositions.

I am going to try some different ways of doing this.

The above cited match-head instructions offer specific directions for coating the tip of the match head with three different homemade compositions: a primer comp, an ignition comp, and a final protective coating.

Or, Skylighter sells the GN5050 Electric Match Dip Kit, which comes with all the necessary chemicals, materials and tools, and instructions (which may be seen by following the above cited links and scrolling down to the GN5050 Dip Kit listing and clicking on “click here for instructions on making electric matches“).

These instructions include very complete safety precautions, which I am not going to repeat here, but which are necessary to understand before proceeding with the following steps.

The first thing I did was to remove the plastic shrouds from the match heads on the pre-soldered blanks.

I used the Skylighter Dip Kit to coat some match blanks, per the instructions in the kit. I found that I had to add quite a bit of the thinner to the mixed first-coat pyrogen to get it thin enough to coat like the directions specify. Use a thin coat, which drips off one drop after dipping the match head into the pyrogen about 3/16″.

I hung the bent matches on a piece of shooting wire strung between two wood posts and allowed them to dry for a couple of hours.

I decided to coat a dozen of the blanks and then apply the finish coat, and then test fire them to make sure the system I’m using is working.

This dip kit will coat hundreds of ematch blanks, so it’s a good idea to prepare all the blanks you want to coat before starting the coating process. Once the pyrogen is mixed, it is uncertain how long a shelf life it has, and you have an explosive slowly setting up in a glass bottle. I recommend mixing it, using it relatively quickly, thinning any excess with more thinner, then pouring it on some newspaper and burning it.

As you are working with the wet pyrogen, don’t allow any dry “crusties” to form on the edge of the bottle top. Push them back with your finger and stir them into the wet mix.

Brian says that the most common sources of failures when using this dip kit are applying the pyrogen too thickly or too far up the match head. Make sure the mix is thinned as per the instructions, and that the heads are only dipped about one third of the way, or about 3/16″. It’s also very important to thoroughly mix the components, and then mix them a bit more. Under-mixing the ingredients is another common cause of ematch failure.

The right consistency will cause one small drip off the end of the match once it is removed from the pyrogen, and a nice, smooth, slightly rounded match head will form.

Once these matches were dry, I coated them about half way up the head, just past the first layer, with the red lacquer finish coating, per the directions.

I wanted to try the dip-coating method described in the instructions for making ematches using Skylighter’s match heads. This process details the mixing of two homemade pyrogen coatings, and then the final application of a nitrocellulose lacquer
finish coating.

Note: This process uses two sensitive compositions–Dark Flash and H3. The directions must be followed precisely to avoid accidents. These compositions are mixed in a wet state. I can’t emphasize enough that these comps become very powerful and sensitive when they dry out. They must be worked with while they are wet. Any excess should be thinned and disposed of while it is still wet.

The “primer” coat is 50/50 potassium chlorate/antimony sulfide. Five grams of the potassium chlorate is screened through a 100-mesh screen. It is then mixed with 5% NC lacquer until a syrup is formed. Next 5 grams of the -325 mesh, dark-pyro antimony sulfide is mixed in. More lacquer can be added to thin the mix until it can be used as in the directions for the dip kit cited above.

Note: Skylighter sells nitrocellulose (NC) lacquer, which is a 25% solution of nitrocellulose in solvent. To make a 5% solution, weigh out some of the 25% lacquer into an empty, clean, one-quart paint can (from Home Depot or similar), filling it about one-eighth full. Then add four times as much acetone (by weight) into the can, close it, and shake to mix thoroughly.

Mixing this comp in an HDPE photo-film canister using a Popsicle or coffee-mixing stick (free at every 7-11), works well. I then dipped some ematch blanks into this comp and allowed them to dry completely.

This primer coating was then coated with the H3 composition. 7.5 grams of potassium chlorate was dampened, as above, with 5% NC lacquer. Then 2.5 grams of airfloat charcoal was added to that mix and stirred thoroughly. Then more lacquer was added until the thin syrup consistency was achieved.

Then the ematches were dipped into this second-coat composition and allowed to dry once again.

Finally I dipped the dry match heads into 5% NC lacquer, completely coating all the pyrogen layers, up about half way on the match heads to create a protective final paint job on each match. Once again, the matches were allowed to dry completely (anywhere from a couple of hours if it is warm to overnight).

I’ve recently heard about a fellow pyro using regular PVC plumbing cement rather than nitrocellulose lacquer to dampen compositions. I decided to repeat the above process using the PVC cement instead of the NC lacquer.

Using this cement produced easy-to-use compositions, and nice, hard, shiny, black match-heads when they were dry.

All three production methods produced nice, very hard, durable ematch heads.

I wanted to see how much electric current it takes to fire these 3 types of homemade electric matches, and also to see how effective they are at igniting a quickmatch fuse. I installed the plastic safety shrouds on all the matches.

Using a little testing apparatus, I determined that the matches will begin to fire once 0.5 – 0.7 amps of electrical current is passed through them. This specification is similar to commercial electric matches and a good rule of thumb out in the field is to maintain at least one amp of firing current in these firing circuits.

Note: The above info yields a simple rule of thumb out in the field when setting up the wiring for fireworks cues. Using a Skylighter 12 cue wireless firing system, which puts out about 4.5 volts with each cue, you’d want to use one ematch and a maximum of 100 feet of the double-stranded, yellow, copper shooting wire
between the panel and the ematch, or a max of 50 feet of the new orange aluminum shooting wire. If you use a 12-volt firing system, maximum length of these “scab” wires would be 300 feet and 180 feet respectively for use with a single elecytiv match. Using a Skylighter GN6010 Electric Firing Box, which generates 300 volts, you can use a virtually unlimited length of firing cable.

I fired each type of electric match several times. The ematches made with the dip kit really pop and throw out a fast flame, similar to commercial electric matches. The ematches made with NC lacquer and homemade pyrogens burn a little less violently and a bit longer and throw out quite a few orange sparks. The similar ematches, made with the PVC cement, burned nicely, and even a bit longer, throwing out a nice flame for about a half second, like a regular safety match would.

I figured that any of these matches would effectively ignite quickmatch if they were installed in contact with the internal blackmatch. I wanted to experiment with one additional step, which would really throw out a lot of flame and would reliably ignite the visco safety fuse on any cake or device out in the field.

I cut 1″ lengths of the super-fast-fuse, which is similar to quickmatch, but which can be shipped. I then used 2″ long pieces of one-inch wide masking tape to secure the fast-fuse into the ends of the ematch plastic shrouds. Then, with some of them, I installed a piece of visco fuse with the freshly-cut end in contact with the end of the fast-fuse, and secured with another length of masking tape.

All the different types of electric matches performed flawlessly and ignited the visco fuse easily. I was very pleased with their performance and with the opportunity to learn more about how reliable electric matches can be homemade for one’s own personal use.

In the future we’ll be detailing the use of these ematches, and how to wire them up with firing systems for reliable ignition, how to plan a consumer fireworks display, and how to make small mortar racks and set the show up for a night’s festivities.

Stay tuned and stay green,

Ned

Cremora Fireballs

Ya know what’s really aggravating? You put many hours of sweat and labor into producing a nice fireworks display, perhaps with some homemade aerial fireworks shells and fountains, and somewhere in the show you fire some of these simple and easy-to-make Cremora fireballs. And after the show, do you hear much praise for the meticulously constructed shells that you slaved over? No! All you hear, especially from the kids, is, “Wow, we loved those big, fiery things! Whaddaya call em? They were hot!”

(Photo and fireball by Noel Emge)

These fireballs are definitely crowd-pleasers. And they couldn’t be easier to make and shoot. The Bluegrass Pyrotechnics Guild has made and shot literally hundreds of the 5 gallon size fireballs in the displays we have produced for the Pyrotechnics Guild International’s (PGI) summer conventions over the years. One time we wanted to replicate an atomic bomb mushroom-cloud in a show that had a World War II segment. We fired 13, five-gallon fireballs which resulted in this smoke cloud after the fire went out.

In another show, we had a Wizard of Oz segment and wanted to have fireballs associated with “The Great Oz Has Spoken” soundtrack. Cremora fireballs provided just the right effect.

In years past I’ve heard of accidents at grain silos or flour mills, where clouds of dust have been ignited by a spark resulting in a tragic explosion. A bag of flour is not a fire hazard, but mix it with air and it becomes a highly flammable mixture.

It takes fuel, oxygen and a heat-source to produce a fire. A Cremora fireball is simply a device which projects a powdered fuel up into the air, where it gets mixed with the atmosphere, is ignited by the propellant, which results in a large fireball as the fuel and air burn together.

At some time in years past, an enterprising soul decided to project some Cremora brand coffee-creamer powder up into the air using a black powder propellant, and the Cremora fireball was born. Even though Cremora brand creamer is next to impossible to find nowadays, and other substitutes are used, these fireball pots will forever be referred to as Cremora Pots, Cremora Bombs or just Cremoras.

The simplest of Cremoras can be made with just a metal can, some black powder, a 4″ piece of Visco safety fuse, a disc cut out of a paper napkin, and some flammable powder.

For a large fireworks display, Cremoras made in 5 gallon plastic buckets produce an impressive fireball for everyone to see. I’ll provide some details on these in a moment, but these fireballs are so large that everyone really needs to be at least 200 feet from them because of safety concerns.

In smaller, backyard type displays, small Cremora pots, made in 12, 15, or 28 ounce metal cans, like what soups and vegetables come in, can produce impressive, safe fireballs. Some folks use cans as large as #10 cans, or even the size of a large coffee can. Small plastic pails and cans work well as containers, too.

Whatever container you use, you want a smooth interior wall, without any lip that protrudes toward the inside at the top of it. You want the contents of the pot to be able to be smoothly propelled skywards.

Warning: Safe is a relative term. As with any fireworks device that propels flame into the air and has the potential to malfunction and send pieces of the container flying, it is always best to maintain safe distances from the device when it fires. Barricade the device with concrete blocks, or bury the pot in a hole in the ground. Nothing would take all the fun out of this faster than having someone get hurt, especially some innocent spectator.

For these small fireballs, I start with a clean, empty can, and punch a Visco-size hole in the side of the can, right near the bottom, with a sharp awl.

Note: It is best to proceed with all of the following procedures with the container in place in the location where the fireball will be shot. We want the flammable powder to stay fluffy, and this prevents the flammable powder from settling as it would if the pot was moved after assembly. If you build it in one place, then transport it to another (thereby settling and compacting the powder), instead of a fireball rolling up into the air, you are more likely to have an explosion of the can itself, possibly injuring yourself or bystanders with metal-can shrapnel. Building the device in its final location also prevents any possible static discharge between it and the ground which could occur if it was lifted up.

Now, I insert the Visco safety fuse through the hole in the base of the can, put the can on the ground, and pour the black powder (BP) lifting charge into the can. I make sure the BP is spread evenly around on the bottom of the container. Then I cover the BP with a round piece of thin tissue, cut from a paper napkin or from facial tissue.

This tissue barrier prevents the flammable Cremora-type powder, which is about to be added to the can, from settling in between the BP granules, which would slow the BP’s burn rate. We want the BP to burn rapidly and develop enough pressure to quickly propel the flammable powder into the air.

Now, it’s just a matter of gently pouring the Cremora-type flammable powder into the can, on top of the tissue-paper barrier, filling the can one-half to two-thirds full. If the powder you are using is clumped a bit, and is not completely free flowing, it is a good idea to sift it through a wire-mesh kitchen colander before pouring it into the can.

The Cremora is now ready to be fired. If it is not going to be fired immediately, cover the device with a piece of aluminum foil to prevent dew, rain, or humidity from affecting the contents.

You’ll want to be a good 30-50 feet away from even one of these small fireballs when it ignites. You will feel the radiant heat from the fireball as it rises into the air. If you test-fire one of these during the daytime, you might see a giant smoke ring form as well.

As you are following along in this process, a few questions have probably now popped into your mind.

• How much and what type of black powder should I use? How does that vary from one size container to the next?
• What kind of Cremora-type flammable powder works best in these babies?
• How could I fire these electrically during a choreographed show?
• Could we add anything to the fireballs to make them more impressive? (We pyros are never happy to leave well-enough alone, are we?)

Commercial 2FA black powder is traditionally used as the lift powder in Cremora fireballs. A good place to start when determining how much of it to use is 0.1 ounce per square inch of container bottom. This results in the following amounts:

3-inch diameter container	0.7 ounce 2FA
4-inch diameter container	1.25 ounces 2FA
5-inch diameter container	2 ounces of 2FA
6-inch diameter container	2.8 ounces of 2FA
7-inch diameter container	3.8 ounces of 2FA
8-inch diameter container	5 ounces of 2FA
9-inch diameter container	6.4 ounces of 2FA
10-inch diameter container	8 ounces of 2FA

These amounts will result in a layer of 2FA on the bottom of the container that covers it completely and is about 1/4″ thick. This is a good starting point, and can be adjusted to taste. The correct amount of lift powder will result in a great fireball, but the container will remain in place and intact.

The first time I ever made 5 gallon Cremora fireballs (10″ diameter bucket bottom), I used a pound of commercial 2FA lift powder in each one. “Yeah, that looks about right,” I said to myself and to those around me. We ended up with great fireballs, and pieces of bucket strewn far and wide. “Hmmm, maybe we can back off on that lift powder a bit.”

In Making & Testing High-Powered Black Powder, we learned that it is possible to make our own, very functional, red-gum/alcohol granulated black powder using Skylighter Airfloat Charcoal, and nothing more than a couple of screens.

This homemade black powder works wonderfully in these Cremora fireball pots. I actually like the slightly softer lift that this homemade BP provides. When using it, I like to use between 1.25 and 1.5 times as much as I would of the commercial 2FA amounts listed in the above table.

When this subject is brought up, quite a few variables are encountered.

There are many different varieties of non-dairy coffee creamer available. As I said above, I was unable to locate the actual Cremora brand. I tested Coffee Mate, Kroger brand creamer, and the cheaper store brands from Wal-Mart and Biggs.

A friend of mine was able to purchase a couple of pallets of out-of-date Vitamite non-dairy powdered milk replacer, and we’ve been making very nice fireballs with it for a couple of years. Vitamite is available from Diehl Food Ingredients, www.diehlinc.com, but it costs $180 for a 50 pound bag.

One member, who has attended the PGI conventions in years past, has brought 50 lb. bags of floor-sweepings from a factory that makes powdered bases for gravy mixes and soups, and has made this powder available to attendees. This powder quite often has a fat-content of 50-60%, and has produced some of the brightest and hottest fireballs I’ve personally ever seen. Very impressive!

I have often used Land-O-Lakes Lamb-Milk-Replacer, and have been very pleased with the results. This product is now up to about $50 for a 25 lb. bag, and is often available at farm-feed supply stores.

Another pyro has used a product called Glufil which is powdered walnut shells. This dust is considerably less expensive, at $22 for a 50 lb bag, and is available at www.rogergeorge.com. I’ve seen photos of fireballs made with it and they looked very nice. The fellow who has used it reported that it did not perform quite as well as Cremora, though.

I’ve heard of folks using fine sawdust, or even wheat flour. One well-respected pyro recently told me that he uses finely powdered Gilsonite, which is an asphalt-like product that is available from Skylighter. I had to mill the Gilsonite that I had on hand to a fine dust in my coffee grinder, because it was originally in the form of larger crystals. Just remember that whatever you use, it must be a very fine, flammable powder.

Well, all of the above information and options certainly calls for some experimenting, doesn’t it? So, I got my lovely assistants, my wife and granddaughter, outside on a nice spring evening after dark, and I made up some small Cremora fireball pots in a 28 oz. can, using many of the flammable powders listed above. At the last moment, I decided to include pots made with Skylighter airfloat charcoal, powdered confectioner’s sugar, and my homemade spruce/pine airfloat charcoal.

Then I fired them one at a time, and we graded each one based on how impressive the fireballs were.

The results were as follows, with the resulting fireballs rated on a scale of 1-5, with 1 being not-so-good, and 5 being “man-that-curled-the-hairs-on-my-arms”:

Wheat flour	2
Kroger brand creamer	2.5
Coffee Mate creamer	2.5
Fine pine sawdust	3
Powdered sugar	3.5	(Interesting purplish flame)
Wal-Mart brand creamer	3.5
Lamb milk replacer	4
Vitamite	4.5	(Lower fireball than others)
Spruce/pine airfloat	5	(Lots of hanging sparks)
Skylighter airfloat	5	(Hot, high, bright fireball)
Gilsonite	5	(Hot, rolling orange and black fireball)

Note: The one thing that kept the Vitamite from receiving a 5 was that it produced a lower fireball. It is a very fine, dense, powder, and tends to be more difficult to blow up into the air and disperse into a large cloud. I came to the conclusion that it needs to be fluffed up a bit, and decided to mix it half-and-half with sawdust in future testing. The performance of any relatively dense powder may be improved by mixing it with some sawdust in order to fluff it up a bit.

These were small, backyard-type fireballs, and I wanted to see how the top performing powders compared in large, display-size Cremoras. So I took some 5 gallon buckets to a recent club shoot, and tested large fireballs there. The results were as follows:

Half-and-Half Coffee Mate/Wal-Mart brand creamer	3
Gilsonite	4
Skylighter airfloat charcoal	4
Lamb milk replacer	5
Half-and-half Vitamite/sawdust	5

These large Cremora fireballs from a distance of 200 feet looked better when they were brighter, and the latter two produced those kinds of fireballs. But, none of the above was bad, and each one produced its own unique effect.

Warning: This can be done easily, but must be done in a particular way in order to be done safely. I have heard of someone being gravely injured when they made a Cremora, with an electric match in the lift powder and the wire leads dangling out of the bucket, and then they lifted the assembly causing a static discharge through the ematch leads and firing the bucket.

First of all, the Cremora pot must be made in place and not moved. Barricade the pot by building it in a hole in the ground, or by placing safe barricades around the bucket. If you are using a 5 gallon bucket, remove the metal handle to prevent it from becoming flying shrapnel in case the bucket is fragmented during firing of the Cremora.

Secondly, quickmatch, or plastic-tape-wrapped Fast-Fuse, must be run into the lift powder from outside the bucket, either through a hole near the bottom, or from the bucket top, down the inside of the bucket and into the black powder. The electric match is then installed into the end of the quickmatch/Fast-Fuse, which insulates the ematch from any static charge that might build up in the Cremora powder.

Then, the Cremora pot is constructed as described above.

Note: Some folks insert an inexpensive metal mixing bowl into the bottom of the bucket, and then install the Cremora fireball ingredients in and above that bowl. I have never done this, but, reportedly, it can increase and improve the upward thrust of the powder and the resulting fireball.

Interestingly, the Cremora fireball pot shown in the picture above, made at the last moment for illustration purposes, was made with the remaining 6 containers of the cheap Kroger coffee creamer that I had purchased for this project. In the small-can test shots, this powder produced only a 2.5-rated, somewhat disappointing fireball. But, the 5-gallon pot’s fireball was very hot and impressive. This suggests there is plenty of room for experimentation and personal taste as these devices are developed and refined.

This is what we call additional effects that ride on top of a main device or effect. I, personally, like Cremoras made simply as described above. But, sometimes powdered metals like titanium or aluminum are sprinkled into or on top of the flammable powder as it is added to the container.

I’ve also seen small aerial fireworks shells, or just individual fireworks stars, placed gently on top of the fireball powder, to be ignited and propelled into the air when the Cremora is fired. This provides some room for creativity on the part of the fireworker, but as usual, safety precautions must be considered, and safe setbacks must be observed. Additionally, after the firing of the Cremora, the site must be inspected for any un-ignited effects.

So, there you have them–some of the simplest, and most effective, fireworks crowd-pleasers you can come up with.

Stay green, have fun, and don’t waste that coffee creamer by actually putting it in coffee.

Ned

Senko Hanabi – Japanese Sparklers

The delicate and subtle Senko Hanabi sparklers were introduced to me Tom DeWille, the founder of Luna Tech in Alabygodbama. Later I had occasion to visit Tom at the Luna Tech plant, and spent a couple of enjoyable days there learning how they make stage and theatrical fireworks from him. Tom has always been very generous with information and withheld nothing when I asked about various techniques and formulas. (Did you know that you can make a 5/8″ glitter mine using micro stars only-with no lift powder? Write me, I’ll tell you how. Write Ned, he might even make an article out of it!)

While we were puttering around Luna Tech’s lab at 0-dark:30 one night Tom pulled out what looked like incense sticks and lit one. The thing morphed into the most unbelievably pretty sparkler I had ever laid my eyeballs on.

“Senko Hanabi,” Tom chortled. “Got ‘em in Japan 20 years ago.”

He souvenired me one pack of them, and I rationed ‘em out to myself at the rate of about one a year, until…

Until I saw these teeny, leetle, twisty, colored paper things that Fred Olsen was selling at a PGI Convention several years later.

Holding one in my hand, quizzical expression on my face.

“Senko Hanabi,” Fred chortled. “Got ‘em specially made in China. Nobody else has got ‘em. Here, take one outside and light it.” Which I did. Very different looking on the outside from the incense-stick jobbies DeWille had given me, but performed very similar.

I came back inside and promptly tried to buy all he had.

“Nope. Haven’t got enough of them. Need to ration ‘em out. Dunno when I can get any more of them out of China,” replied Fred.

I bought as many as he would spare, and spent the next 7 years rationing them out to friends and family. And when they lit them, always the same “oohs” and “aahhs.”

But Fred didn’t have any more. I asked every Chinese-connected human bean I knew about getting Senko Hanabis. I met either a blank stare on the phone, or a flat “nope.”

When I first went to China a few years back, I bought Skylighter’s initial container of fireworks directly from the factories owned by Shogun. Shogun’s a really great company. Good people, good product. And they were very helpful to me, a newbie at the game, particularly Joe Wan, one of the company’s owners, and John Werner, their US based product designer.

One day we found ourselves at a factory which makes Morning Glory sparklers, and were poking around the ubiquitous fireworks factory sample shelves-where they display every firework they have ever made for anybody, in any country, in every language, at any time since the last dinosaur croaked.

Lo and behold, there, back behind some 7-inch long firecrackers, was a little bundle of Fred Olsen’s twisty paper style Senkos!

Feigning indifference, I blurted “Quick, ask him if he can make these,” to our translator.

The factory manager called a minion into his office, held a single Senko Hanabi sparkler up, and the guy took off at a trot somewhere. 15 Chinese minutes later he’s back holding a small bundle of freshly made Senko Hanabis in front of my dollar encrusted eyeballs, now blinking rapidly to try and reduce the shine in them.

Outside, they burned and sparkled perfectly. The golden, molten globule forming, shrinking, vibrating, and then finally exploding into the most fabulous sparkler spray of all sparklers! Bingo!

But my visions of retiring on Senko Hanabis were quickly quashed. “Nope. Cain’t make ‘em,” he said in perfect Caintonese.

“Too much trouble. Takes too much time. Too much labor. Too expensive to make now.”

“How expensive?” retorts I (I’m an American, for God’s sake. Money is no object.)

“I dunno. I’ll have my guy get back to your guy on it,” he says.

Well, more than 5 years later, his guy has never gotten back to my guy.

Jump to November 2007. Back in China, this time with my Ace Fireworks Finder, Matt Palaszynski.

For the past 3 years, Matt has known about my quest for the Holy Senko. Now, he has finally found a factory that used to make them. But they have not made them for years (there must be a reason). And he doesn’t know if they’re willing to do it again. We are scheduled to meet the factory owner this morning to see.

We drive through one of the rat-mazes of little, windey, one-lane concrete roads outside Liuyang, me and Anne, with Annie the translator, and Matt. Much cell-phone back-and-forthing, the factory owner homing us in on his office.

We all arrive at his office at about the same time, him on his motorcycle, us in the car. Handshakes all around, the obligatory offering and declines of his cigarettes. Then we get down to bidness.

He fumbles around in his coat and produces a bundle of the sacred Senko Hanabis.

My ears start getting tingly, the hackles rise on my neck, and my wallet pocket starts throbbing. Furtively, I pull my coat down to hide it! Cain’t let him see. Cain’t let him find out that I don’t CARE what they cost! I just have to have these wonderful little twisty paper things.

I try to put on my stupidest, semi-interested, inscrutable Westerner’s face, one big “huh?”

I like this guy. He seems a little hungrier than some of his nouveau-riche fireworks company compadres. And he did arrive on a motorcycle, not a fancy dancy new car. I can work with this guy. And yep, he IS willing to make them.

Pricing is put off for another day, to be haggled back and forth by Matt and the factory owner and me, based in part on quantity I agree to order, packaging, and other factors.

We shake hands, I toodle off, all satisfaction and afterglow, with Anne and my pals, and I offer to buy lunch for all, secure in my final victory that I have found the elusive Senko Hanabis and will finally be able to get them to my insatiable customers in the good ole US of A.

But if you want to tackle the intricate mysteries of making Senko Hanabi yourownself, you can read Ned Gorski’s article below on making them. They are tricky little devils, requiring a fine balance of potassium nitrate, charcoal, and sulfur. And if you already have those three chemicals, you can do it easily with just a little tissue paper. Ned takes all the guesswork and hair pulling out of the process for you.

Senko Hanabi Sparklers, #NV0500

In the past, I’ve kiddingly told fellow pyros that, at one time or another, I’ve made, or at least have tried to make, every kind of fireworks device except for snakes. That was before I heard about Senko Hanabi, though, and realized that I didn’t even know what they are.

I’ve made some firework sparklers in years past, and Senko Hanabi are a kind of Japanese sparkler in the strict sense of the word. But, after a friend gave some of them to me last year, I realized I’d never tried to make anything like them.

According to Shimizu in Fireworks, the Art, Science and Technique (”FAST”), Senko Hanabi is a traditional Japanese firework, and essays about them date back to at least 1927. One Japanese-to-English, online dictionary spells it Senkouhanabi, and defines the word as “toy fireworks.” Hanabi means “flowers of fire,” and these sparklers produce miniature versions of them.

Senko is defined as “all ages,” and perhaps refers to the fact that this firework can be enjoyed by people of all ages. Senkou is said to refer to “incense stick” and this type of sparkler has, indeed been made on sticks, which resemble incense.

The word “sparkler” may be a bit misleading to us in the USA, though, because of what it brings to mind. Metal wires or wood sticks, dipped in pyrotechnic compositions, emitting bright sparks and lots of heat when they burn. “Be careful around your sister’s eyes with that glowing metal wire,” Mom would shout.

This Japanese version of the firework sparkler is much more delicate and subtle than what we are used to, though and a lot more safe as well. I remember how startled I felt when I first got one of these to work, and it began emitting amazingly complex, delicate, branching sparks, shooting out four to eight inches. Like fire-snowflakes, I thought. I was amazed.

After I burned through a pack of them, I decided to send my Mom and Dad a bundle of these colorful little sticks. My folks are in their 80’s and live in California, so I certainly wouldn’t have been comfortable sending them any real “fireworks,” but I just had to show them these mysterious little sparklers. I was excited as I imagined them going out onto their deck and burning a few of ‘em.

“You are going to be amazed by what you see when these little things really start doing their thing,” I told them.

Here’s a photo of an individual Senko Hanabi.

The bulging section toward the left end is what contains the sparkler composition. The comp is contained in twisted tissue paper, which can be fairly easily untwisted to empty the contents.

The composition is a very dark black powder. And there is not much of it in there. I have an electronic scale, which is precise to one-tenth of a gram. It would not register the weight of the composition that I removed from this sparkler. It barely covered the tip of a one-eighth teaspoon measuring spoon. Its quantity equals about as much salt as you’d get if you shook your salt shaker a couple of times.

The rest of the sparkler, the handle, is also composed of tightly rolled up tissue paper. It feels as though it has been stiffened with a bit of a binder or glue of some sort.

To get a Senko Hanabi to work, you hang the composition end of it straight down from your hand. Make sure you are in an area with no wind, steady your hand, and then light that lower end. To really see the effect, it’s best to do this in the dark, and in a ventilated area, but without wind, so you don’t have to breathe the strong sulfur smoke.

The tip will burn up to the bundle of composition, which will begin to slowly burn, and if you are holding it still enough, a little blob of orange, glowing, molten slag will form. This is reportedly potassium sulfide, which contains carbon from the charcoal.

Then, all of a sudden, this molten ball will begin to emit the most amazing, delicate, branching sparks, often looking like fire-snowflakes. When you see this for the first time you’ll be amazed.

I tried, over and over, to get a nice photograph of this phenomenon and failed miserably. This shot might give you the slightest impression of what the effect is like. You really have to see it in person to appreciate it.

There are several Senko Hanabi tutorials available on the Internet, and, as far as I can tell, all the information is based on the information contained in Shimizu’s FAST.

The black composition is a simple one, consisting of three basic chemicals: potassium nitrate, sulfur, and charcoal.

These are combined in a ratio of 60% potassium nitrate, 20-30% sulfur, and 10-20% charcoal. This is a typical black powder composition, but the quantity of the sulfur is doubled or even tripled.

Sometimes lampblack or soot is used instead of charcoal. If charcoal is used, the type of charcoal will influence the resulting sparks. Some folks use charcoal that is made of tissue paper or paper towel, soaked in a sugar solution, and cooked in a retort until it becomes a form of charcoal. See How to Make Charcoal , for details on cooking charcoal.

Shimizu also lists an alternate composition, consisting of 35% potassium nitrate, 45% realgar, and 20% charcoal or soot. Realgar is a chemical that is listed as a component of some old fireworks formulae, but it is seldom used nowadays because it has become unavailable, and it contains arsenic, which can be a bad thing in smoke if it is inhaled!

Note: I do have a small quantity of realgar, and I tried the above formula in Senko Hanabi. Shimizu states that realgar will produce “larger and more beautiful sparks than with sulfur.” In the minimal experimenting I performed using it, I did not find that it performed as well as the sulfur. And, when the composition burns, it emits a thick, yellow smoke, which I was not all that thrilled to be around.

My technique for making these experimental Senko Hanabi was as follows:

Weigh out chemicals in individual paper cups. Grind potassium nitrate and sulfur individually in a small coffee grinder until the chemicals are very fine. Combine and screen those chemicals with the airfloat charcoal through a 100-mesh screen several times.

I began by using 16.5 grams of the potassium nitrate, 6.5 grams of sulfur, and 4.5 grams of airfloat charcoal. (This is approximately a 60/25/15 proportion of the components.)

Cut a piece of tissue paper, 1/2″ x 2 1/2″.

With slightly dampened thumbs and index fingers, begin to roll the tissue paper up at the ends, as if I’m rolling a cigarette. (Having come of age in the 60’s and 70’s, I, of course, would know nothing about this process.)

I now dip the end of my 1/8-teaspoon, measuring spoon in my composition and scoop out just that little bit of comp. I tap the powder out of the spoon into the little, rolled trough that was formed in my tissue paper.

Then it’s just a matter of using my fingers to finish rolling the little sparkler and really twisting it into a tight little bundle. I like to hold my homemade sparklers with a pair of tweezers, or a hemostat, in preparation for burning it.

When I made the first sparklers, using the composition listed above, they burned far too fast and did not form the little ball of slag which is necessary for the resulting final sparks to let fly.

So, I started to add more charcoal, one half gram at a time, as one would do to slow down a black powder rocket composition. This did end up retarding the burn speed, but the slag ball and the sparks never ended up forming.

Back to the drawing board. Since the original comp was burning too rapidly, I thought I’d start with the charcoal and sulfur components, and slowly add potassium nitrate until hopefully the desired results were achieved.

I ground the 6.5 grams of sulfur in my small coffee mill, and screened it in with my 4.5 grams of charcoal. I weighed out the 16.5 grams of potassium nitrate and milled it by itself in the coffee mill.

Then I started to add the potassium nitrate to the sulfur/charcoal mix a little at a time, starting with 4 grams and adding it in 1-gram increments. I tested the composition after each increase in the oxidizer, and after adding 11 grams of it, the ball of slag started to form and it began emitting the sparks I was after.

With a total of 12 grams of the potassium nitrate in the mix, the sparklers were working very well, and when I added another gram bringing the total to 13 grams, they started to burn too quickly as in my first experiments.

Component	Parts	Percent
Potassium Nitrate	12	52%
Charcoal	4.5	20%
Sulfur	6.5	28%
Totals	23	100%

This final formula is in the range of proportions that Shimizu demonstrated to work.

I tried both commercial airfloat and homemade spruce/pine airfloat charcoals, and they both worked well. The homemade charcoal produced sparks which were slightly larger.

I tried the lampblack that I had on hand in the formula, instead of charcoal, but I could not get it to work and produce sparks.

If I were going to make “production models” of these babies, I’d glue the tissue paper bundles to a bamboo skewer, or toothpick, handle.

Dr. Shimizu goes into much greater detail concerning the chemistry dynamics of the Senko Hanabi process, and other optional formulae, ingredients, and manufacturing processes.

When I first got into fireworking, one question was paramount in my mind: “How the heck do they do that?” I’ve continued to ask that about almost every pyrotechnic device I’ve seen, and I’m glad that Dr. Shimizu and others have left pointers along the way so that I could learn more about how these things are made.

Until next time, Enjoy!

Ned

Really Nice 4″ Plastic Ball Firework Shells

In this article I am going to describe a way that I make 4″ plastic ball shells. I want to emphasize the “One Way” part of this article’s title, though.

In Volume 2 of Bill Ofca’s Technique in Fire series, Design and Quick Assembly of 3, 4, and 5 Inch Plastic Ball Shells, some interesting and useful methods are described, and it was this booklet that I followed when I first started building plastic ball shells years ago.

Lloyd Sponenburgh has another way of building these aerial shells, as described in his Passfire.com
article, 4″ Plastic Ball Shell. I’ve played with Lloyd’s methods a bit as well. At regional club events, he has taught probably hundreds of folks how to build these firework shells his way.

One thing that I’ve discovered over the years is that there are many ways to skin the cat in fireworking, and that there is much we can learn from each other. Usually each of us adopts a hybrid, personal way of doing things. And, each person’s way can change and evolve over the years.

I do think my methods include some unique ways of approaching the subject, and I hope the information in here can be useful to both the beginning fireworker and the seasoned pyro who is curious about how someone else does things. Suffice it to say, I am very pleased with how these shells perform using my method.

So, this article is simply a description of my current, personal, hybrid way of building these shells. But my way will probably evolve to be a little different in a year or two. Beyond just discussing how to build one of these shells, though, I’d like to ponder how to think about some of the various aspects of the shell’s construction.

First, look at the basic design of a 4″ plastic ball shell in the diagram below.

Next, you may want to review the following articles. Parts of this project depend on the referenced articles below.

• Making and Testing High Powered Black Powder
• How to Make Cut Firework Stars in an Hour or Less
• How to Make Wonderful Zinc Firework Stars
• The making blackmatch and quickmatch sections of Firework Shells in 2-1/2 Days: Part 2 and Part 4
• The shell construction details in Nice Shells in 2 1/2 Days, Part 3

• 4″ spherical shell set (Skylighter #PL2060)
• Approximately 1# of stars
• Approximately 4 oz. of break charge/burst powder
• Optional slow flash burst additive
• Approximately 2 oz. of lift powder
• 30″ of quickmatch (or fast fuse and foil duct tape) (Skylighter #GN3001, or #GN1205)
• 4″ Visco fuse (Skylighter #GN1000)
• 2″ piece of 1/4″ time fuse (Skylighter #GN2000)
• Cross match, (blackmatch or Visco cross-match, Skylighter #GN1010)
• One piece of printer paper
• Fiberglass Reinforcing strapping tape, or gummed kraft tape
• Plumber’s heavy-duty PVC cement
• Lift cup
• Hot glue and glue-gun
• Tissue paper (Skylighter #MS1110)
• Thin string
• Weighing scale (Skylighter #TL5020, #TL5030)
• 4″ Fiberglass Mortar Tube (#PL3184)
• Shell support tubes
• Sharp, single-edge, razor blade
• Aluminum foil duct tape
• Rice Hulls (optional) (#CH8236)

In Fireworks, the Art, Science and Technique (FAST), Dr. Shimizu includes a table on page 252 which lists firework shell sizes, and the corresponding recommendations for star size, number of stars, and amount of bursting charge. Based on that firework star sizing information, I’ve developed the following little graph:

This graph, of course, only shows a starting point when sizing stars for a shell. How fast does the star burn? Some burn much faster than others. Do I want a dense burst of smaller stars, or a Palm Tree burst of very large stars? The individual fireworker must experiment and develop their own personal preferences.

The chart shows that a good starting point would be 7/16″ stars for this 4″ ball shell. The FAST chart also indicates that approximately 170 round stars of this size would be used in the shell. But I’ll be using cut stars in this particular shell, so that number will probably vary.

The weight of the stars in the shell will vary considerably with the type of star. It might take only 8-10 oz. of a lightweight star such as Willow, or up to almost a pound of a dense star like a zinc star.

In the booklets cited above Ofca and Sponenburgh employ variations of a flash powder bursting charge, with Lloyd combining his hot-flash powder charge with some black powder.

In Shimizu’s FAST, pages 207-214, there is an extensive discussion of potassium chlorate bursting charge (H3), potassium perchlorate bursting charges (KP), and black powder bursting charge (BP). Various considerations are discussed, and possible cores for coating the charges on are explored, as well as coating ratios.

For shells smaller than 4″, Shimizu recommends the H3 burst charge, and for larger shells he specifies either the KP or BP burst powders.

I personally like to stick with black powder burst charges, sometimes augmented with a slow flash powder burst additive, which I’ll describe later.

An interesting subject is the density of various burst charges. These can be useful to know when choosing a burst powder for a particular shell.

Commercial 2FA powder	(0.70 ounces/cubic inch)
Black powder granulated with red-gum/alcohol	(0.35 ounces/cubic inch)
Black powder on rice hulls or puffed rice	(0.26 ounces/cubic inch)
Black powder on cotton seeds	(quite a bit less dense than even the BP on rice hulls)

Once again, in the FAST chart cited above, specific amounts of burst charge are specified for particular shell sizes. A little calculating will show that a burst charge density of 0.45 oz./cubic inch is specified for 3″ shells, 0.31 oz./cubic inch for 4″, and for shell sizes 5″ through 12″, a burst charge density of approximately 0.25 oz./cubic inch is recommended.

So, for our 4″ shell, our granulated BP with red-gum/alcohol and having a density of 0.35 oz./cubic inch is just about perfect.

I have 1/4″ time fuses that burn anywhere from 2.2 to 3.1 seconds per inch. I want a 2 second delay from my time fuse in this 4″ shell. I’ll typically use a time fuse delay (in seconds) of half the shell’s diameter. So, I need an actual time fuse length, between cross-matches, of between 5/8″ and 7/8.” I could just split the difference and use 3/4,” but I like to be more precise in my fireworking.

I have a new roll of time fuse and I don’t know how fast it burns. So, I cut 10″ of it, lay that piece on the ground in a safe location away from any flammables, light one end of it with my torch at the same time that I start my stopwatch, and I stop the stopwatch when flame spurts out the other end of the fuse.

This 10″ piece of fuse burned for 21.65 seconds, which is close enough to 22 seconds for me. Dividing that 22 seconds by the 10 inches gives me a fuse burn rate of 2.2 seconds per inch. I put a masking tape flag label on one end of my roll of fuse indicating its burn rate for future reference.

I’m a bit on the particular side. My wife would say that I’m a bit compulsive and anal, but I know she’s just kidding. I hope. Anyway, I actually cut 10″ from each end of the roll of this fuse and time each of those pieces. Each one burned for about 22 seconds, so I know that figure is accurate for this roll of fuse. Heck, how do I know for sure that the machine and operator making this fuse stayed consistent the whole way through?

Using this fuse then, I’ll make sure that I have my desired delay of 2 seconds, divided by the 2.2 seconds/inch, equaling 0.9 inches of time fuse between cross-matches. This is almost exactly 7/8.”

Well, I think we can start to actually build this baby now.

I heat the hot-glue gun up. I have had good luck with Arrow glue guns and glue sticks from Home Depot. A gun and a bag of sticks for under $25.

Note: For hot-glue-gun safety tips, see Nice Shells in 2-1/2 Days: Part 3.

I want 7/8″ of actual time fuse delay, and I’m gonna split each end 1/2″ with my razor blade for cross-matching. So I cut a 1-7/8″ piece of the time fuse with the razor blade. I put marks with a Sharpie in 1/2″ from each end of the fuse.

Warning: Fuse is never cut with scissors because it can be ignited by the friction of that kind of cutting. Fuse is always cut with a razor blade, or with an anvil cutter that uses a razor blade for the cutting.

Then I carefully split one end of the fuse down 1/2″ (the actual blade on my razor is 1/2″ wide), insert three 4″ pieces of the cross-match, and tie the split ends of the fuse back together with string and a clove hitch knot and an overhand knot to secure the clove hitch. I split the fuse right down its center, disturbing the black powder core as little as possible.

Note: Skylighter’s Super Fast Paper Fuse (#GN1205) has 3 strands of thin black match in it which are perfect for cross-matching.

I hot-glue the fuse-washer onto the correct hemisphere.

I then give the fuse a trial fit in the hemisphere fuse hole to make sure it inserts easily. If it does not, it is OK to slightly enlarge the hole with a correct diameter drill bit and drill.

When I know the fuse will fit in the hole easily, I apply a bead of hot-glue around the middle of the fuse. Then, with the cross-matched end inside the casing, the fuse is quickly inserted into the casing while the glue is still hot. (When the fuse is inserted into the hemi, the hot glue becomes a seal between the fuse and the hemi, being dragged with the fuse into the casing and forming the fillet on the inside.) I push the fuse through until the fuse’s outside Sharpie mark is about 1/4″ beyond the outside edge of the fuse-washer.

Then, I apply hot-glue around the fuse outside of the shell, filling the recess in the fuse washer, and building up another fillet of glue around the fuse.

Note: These hot-glue fillets, inside and outside the shell casing, are very important. They keep the lift gasses out of the shell when it is launched skyward. For this reason, the glue seals must be solid and secure, without any gaps.

A passfire tube is made of a 1-1/2″ x 4-1/2″ piece of paper, rolled up on a 3/8″ dowel. This tube is inserted over the cross-matched fuse in the shell casing, and embedded in a ring of hot-glue to seal it to the casing. This tube conveys fire to the center of the shell after the time fuse burns through to the cross-match, which improves the symmetry of the shell’s burst. It doesn’t hurt to insert a few more pieces of blackmatch into the passfire tube at this time to increase fire transfer to the shell’s center.

A 1/8″ hole is drilled all the way into the un-fused hemisphere, through the recess where the lift ring will eventually be installed. This vent hole will allow air to escape from the shell when the two halves are glued together. If this hole is not drilled, the air will have to escape from the equator, which may very well leave voids in the equatorial seal. This could, in turn, let lift gasses in and cause a “flowerpot.” (A flowerpot is a shell bursting in the mortar and performing like a mine.)

Now, as described in Skylighter Fireworks Tips #93, I put the shell casing hemispheres on sections of PVC pipe which serve as work stands, and I lightly hot-glue rings of stars in the hemis flush with their equators.

Note: It is important in the un-fused hemi, that you glue and position the stars below the equator’s recessed edge, so that the halves will mate when the shell is closed.

Then the remaining stars are fitted into the casings without any gluing. The little wedge shaped stars that were created in the star-cutting process come in handy for filling odd-shaped voids.

Now, I line the shell and cover the stars with tissue paper, fill the centers with homemade, granulated black powder burst charge, loosely dump in the optional slow flash powder booster (see note below), and tap the casings to settle the powder. Then I cover it all with, and glue on, discs of tissue paper after trimming the excess tissue paper off.

Note: I’m very careful when it comes to clipping the excess tissue paper off with scissors. I never cut through any paper that has burst powder on it, and I keep the scissors clear of any area of the paper that does.

The optional slow flash burst powder does not have to be used, and typically it would not be used for a softly-breaking shell like a Willow. It can be used in a shell where a hard, symmetrical break is desired.

This powder is a 2/1/1 mixture of potassium nitrate, sulfur, and American-dark or any 325 mesh bright flake aluminum. The individual chemicals are individually screened and are only mixed gently by rolling them together on a piece of paper. This is called the diaper-method of mixing flash powder.

For this 4″ shell, I used 0.6 oz. of the slow flash powder, which was made of 0.3 oz. of the potassium nitrate, 0.15 oz. of sulfur, and 0.15 oz. of the aluminum.

Now it’s time to close this shell up. I use heavy-duty PVC plumber’s glue to glue the shell halves together. Using the glue can’s applicator, I apply glue liberally to the mating surfaces of each hemisphere, and close the shell, twisting the hemis together until they won’t move any more. I then wipe the excess glue off with a piece of kraft paper, and reinforce the seal/joint with masking tape, pulling the two hemis together as I do so.

Using the same glue, I fasten the leader-hook/lift-ring, which securely seals the vent hole we drilled.

I apply 4 rings of reinforcing, strapping tape, one around the equator, and the other three evenly spaced, striving for a finished shell circumference of 12.” Each ring of tape is 3 layers of tape thick.

I like to cover the shell at this point with aluminum foil duct tape to flame-proof the strapping tape, and to make the shell look a bit more presentable. I also split, cross-match, and tie the outside of the time fuse in the same way that I did the inside of the fuse.

I have found that Skylighter Super Fast Paper Fuse
can be wrapped in foil tape, which has been cut down the middle to form 1″ wide tape, in order to create very nice quickmatch if one cannot buy or does not want to make their own.

I cut a piece of quickmatch 30″ long and make sure bare black match is sticking out 1″ from the end that will be in the shell’s lift powder. I weigh out 1.5 oz. of commercial 2FA black powder, or about two ounces of homemade BP lift powder, put it in a thin plastic baggie, insert the bare match end of the quickmatch leader and tape the baggie closed. I cut the excess plastic off, and tape the baggie securely to the leader.

Then the baggie of lift powder is centered on the shell’s time fuse, then covered with a lift cup which is hot-glued in place, and the leader is routed as shown. For a lift cup, a cone-shaped drinking cup can be used as shown. A flat bottom paper cup or a homemade, funnel-shaped paper lift bag can also be used.

I like to hot-glue the leader to the side of the shell to further secure it, and then I tape some visco safety fuse into its end.

At this point a label can be affixed to the shell to identify it, if so desired.

This is how this 4″ zinc star-shell broke. You can see that it is a nice, big, round, symmetrical break. Just what I was looking for.

Have fun and Stay Green,

Ned

How to Make Wonderful Zinc Firework Stars

Now and then on the pyro discussion lists someone will bring up the subject of zinc stars. Usually several folks will chime in with, “Oh, man, those stars are some of my favorites, so subtle and beautiful.”

In Chapter 15 on Fireworks, of Alexander Hardt’s Pyrotechnics, (this chapter written by Barry Bush after Dr. Hardt’s death), it is stated, “Good zinc stars are blue-green with tails of delicate gold, and seem rather exotic today.”

This is a color star where the color is produced by an elemental metal, rather than a metallic salt, such as when a blue is produced with a copper oxide or carbonate. So, this blue-green color star may be among the oldest firework star colors that were produced.

Back in the early 90’s when I first started making stars, there was not much fireworking information available. I was able to get my hands on a copy of the then recently reprinted Pyrotechnics, by George Weingart. Some of my first star-making efforts were based on a few of the formulae contained in that book, and perhaps my favorite of them was the Granite Star.

An added bonus is that this is one of the easiest cut stars to make that I’ve tried.

Component	Parts	Percent	Decimal
Potassium Nitrate	14	22%	(0.22)
Zinc dust	40	62%	(0.62)
Fine charcoal	7	11%	(0.11)
Sulfur	2.5	4%	(0.04)
Dextrin	1	2%	(0.02)
Totals	64.5	101%	(1.01)

(The percentages, because of number rounding, actually add up to 101%, but that’s OK, and they’ll work just fine. The percentages of each individual chemical in the star composition are calculated by taking the original number of parts of that chemical, say 14 parts of KNO3, and dividing that number by the total number of parts, 64.5 in this case. 14/64.5=.217, which can be rounded to .22, which is 22 hundredths or 22%.)

Note: You may be saying to yourself, “I wonder why he’s including those decimal numbers after the percentage numbers.” I’ll show ya in a minute. The decimals are much more useful than the percentages.

Harry Gilliam, in the last blog post, published the formulae that he inherited from the Kosankes when he purchased the business that became Skylighter. In that list of formulae is one called Pearl, and it is a slightly different version of a zinc star:

Component	Parts	Percent	Decimal
Potassium Nitrate	35	35%	(0.35)
Airfloat charcoal	15	15%	(0.15)
Zinc dust	40	40%	(0.40)
Sulfur	5	5%	(0.05)
Dextrin	5	5%	(0.05)
Totals	100	100%	(1.00)

I always like to look at star formulae and see how they differ from each other. It can be seen that the second formula uses less zinc powder, more KNO3, and slightly more charcoal, sulfur and dextrin.

There is a formula in Hardt’s book that is similar to the Kosanke formula above, but the zinc is increased to 45%, and some Meal D black powder is used in it, as well as potassium nitrate, charcoal and dextrin.

I, personally, have only made zinc stars using the first formula, from Weingart, the Granite Star.

In a recent discussion in the Passfire.com Forum, a fellow fireworker, who has worked quite a bit with this star, recommended that the charcoal used in the formula be half airfloat and half 80 mesh. This improves the charcoal tail that the star leaves behind as it burns. Back in the ’90’s when I made the star, I’d only use airfloat, so this is another area of experimentation as an individual fine tunes the formula to his own personal tastes.

These stars light easily, especially when made as cut stars with all the corners and edges to take and hold fire, so I’ve always just primed them with a “scratch-mixed” (mixed by hand, no milling) black powder prime, simply screened through a 40 mesh screen.

Component	Parts	Percent	Decimal
Potassium Nitrate	75 OR 15	75%	(0.75)
Airfloat charcoal	15 OR 3	15%	(0.15)
Sulfur	10 OR 2	10%	(0.10)
Dextrin	5 OR 1	+5%	(0.05)
Totals	105 OR 21	105%	(1.05)

Note: This is simply 75/15/10, KNO3/charcoal/sulfur (the classic black powder proportions), with an additional 5 parts of dextrin added as a binder (additional 5%). One of the few formulae that I can always remember off the top of my head is the 15/3/2/1 parts proportion of this composition. If I want to make 21 ounces of prime, I simply weigh out 15/3/2/1 ounces of each chemical and screen them together.

This is a very heavy and dense star, perhaps the heaviest I have ever made. (I haven’t made stars using gold powder yet!) A 4″ ball shell will use a little less than a pound of these primed stars. A 4″ mine would use about the same amount. In my small-scale, hobbyist fireworking endeavors, I actually like making stars a pound at a time, especially when experimenting with new formulae.

Using the first formula, above:

Component	Decimal		Batch Weight		Weight
Potassium Nitrate	0.22	x	16 oz.	=	3.5 oz.
Zinc dust	0.62	x	16 oz.	=	9.9 oz.
Fine charcoal	0.11	x	16 oz.	=	1.75 oz.
Sulfur	0.04	x	16 oz.	=	0.65 oz.
Dextrin	0.02	x	16 oz.	=	0.3 oz.
Totals	1.01	x	16 oz.	=	16.1 oz.

Now do ya see how handy those decimals are? Of course, any final batch size can be plugged in instead of the 16 oz. A 32 oz. batch, or a 100 gram batch, can be calculated just as easily.

The charcoal can be all airfloat, or it can be half-and-half airfloat and 80 mesh, as mentioned above.

What the heck is zinc, anyway? I don’t know about you, but zinc is not one of those chemicals I’m all that familiar with. In the back of my head all I kinda knew about zinc was that it was coated onto the steel garbage cans of my youth to keep them from rusting. Galvanization they called it. Same stuff that’s on the steel ductwork leading to and from my furnace. I actually had to look zinc up to verify that it is, indeed, an element like gold and copper. Shows ya how much of a chemist I am.

An interesting thing about the zinc powder that we use in Granite Stars is that it doesn’t stay powder for long. It forms clumps. Either at the supply house, or in our storage, zinc powder will become zinc clumps, because it oxidizes in moist air.

Unless these clumps have been allowed to harden for years, they can be broken up simply by rubbing them on a 100 mesh screen. I recently received a shipment of zinc dust which had formed these clumps, and I was quickly able to return the metal to a dust through my screen.

Note: Zinc is reportedly not toxic, but I can tell you from experience that it is irritating if it is inhaled during the above screening process, or during the manufacture of zinc stars. I mean Really Irritating in the nasal passages. I’m not saying this as some kind of CYA. Wear a good respirator when working with zinc dust. Really, no kidding.

I use a good, $25 respirator, from Home Depot which is rated for fine dusts as well as fumes.

Zinc stars burn relatively slowly, and if they are made too large they will burn all the way to the ground, especially if used in a mine. Therefore, I like to make the stars a bit on the small side. For 4″ shells and mines, I like to cut the stars 5/16″ square, and once they are primed they end up being about 3/8″ square. For a more dense spray of stars, they could even be cut 1/4″ and this would work well for smaller shells as well.

I am working outdoors and away from any sources of ignition.

I have screened 21 oz. of my BP prime through my 40 mesh screen and I have it in a closed container. I always keep every flammable composition in closed containers until they are actually being used. This minimizes the amount of exposed materials in case there is a stray spark or fire.

I have screened my 9.9 oz. of zinc through my 100 mesh screen.

I weigh the rest of my chemicals into individual containers, add them all together with the zinc, and screen the complete star composition 3 times through my 40 mesh screen to completely pulverize and mix the components.

Then I weigh the composition in a plastic bucket to make sure that it totals up to the 16.1 ounces of weight that it should, thereby insuring that I didn’t make any mistakes when weighing the individual chemicals, or leave one out completely. This step can prevent a lot of mistakes and wasted chemicals.

I put a lid on the bucket and shake it to further mix the ingredients.

Then, with rubber-gloved hands, I start to work water into the composition until workable putty is developed. It’s OK to start adding water out of a jug a little at a time, until the composition starts to get dampened. But, the final increments of water ought to be added by spraying it out of a little, plastic spray bottle. This prevents the addition of too much water, which makes for a pain in the butt. It’s always easier to add a bit more water than it is to remove a little.

As I add the water, the comp will clump-up, form a hard ball, and finally, when enough water has been worked in, it forms a nice, workable ball of dough which will flatten out smoothly when patted with a hand. My one-pound batch of star-comp required 2.6 ounces of water to get to this point, which is about an additional 16% (0.16) by weight.

I have two, 14″ x 17,” 3/8″ thick, black-plastic cutting boards from Kmart or Target that I use to cut stars on. I’ll take one of the cutting boards, cover it with wax-paper, put the star dough-ball on it, and put 5/16″ spacer dowels on either side of the comp.

Then I’ll flatten the ball by hand a bit and cover it with another piece of wax paper. Then, using a rolling pin or a rocket tube, I’ll further flatten the comp until it’s just as thick as the spacer dowels, 5/16″ in this case.

Now, the top piece of wax paper is removed and set aside, and the spacers are removed, too. The tub of star-prime is opened and some of it is evenly dusted onto the pancake using a small cup or a measuring spoon.

The piece of wax paper is replaced on top of the pancake. Then fold the edges of the bottom and top pieces of paper together a couple of inches.

You’ll see how helpful this step is in a minute. Then place the other cutting board on top of it all, press down a bit to compress the prime onto the pancake, and lift both cutting boards and flip them over, keeping the folded edges of the wax paper down so that the loose prime can’t fall out from between the pieces of paper.

Remove the top cutting board and the top piece of wax paper. Now, dust the exposed side of the pancake with prime so that both sides have been coated in the prime.

Now we’re ready to do some star-cutting. I love the knife that a fellow pyro turned me onto years ago, that I use for cutting stars. It’s a thin-bladed, very sharp, very straight edged, meat-slicing knife from McMaster-Carr. It costs $26 nowadays, and is part number 3851A11.

I cut and filed off the little plastic handle extension that hung down below the edge of the blade so that I could press the blade all the way down to the cutting board.

I start cutting the pancake of star comp into strips 5/16″ wide, sliding the strips aside and flipping them over so that the primed edges are against each successive strip.

Note: The star comp can try to stick to the knife during this process. If a strip is clinging to the knife, it’s easy to raise the knife a bit and rap its end on the cutting board, knocking the strip downward and off of it.

Then I sprinkle more prime on the strips, put the wax paper on the strips, fold over the edges of the two layers of paper again, put on the other cutting board, and flip the whole deal, keeping the folded paper edges down again. The top cutting board is removed as well as the top piece of paper, and that side of the strips is now dusted with prime.

Star prime is your friend in this process, and later on when you use the stars in a device. Don’t use it sparingly. Use it liberally. Bam. Just like that cooking guy, what’s his name? Emeril, yeah, that’s it.

The strips are now cut into 5/16″ cubes, with the rows of cubes being flipped over as much as possible to keep primed edges touching each other.

Now, it’s easy to raise the edges of the wax paper and roll the stars onto each other, breaking up any that are clinging to each other, and fully coating all the cut sides with prime.

I like to dump the whole mess into a large plastic container, swirl them around a bit, and lightly spritz the stars with the water sprayer until they have fully gathered all of the star prime onto themselves. If I get them a little too wet, I add more prime, until a nice, thick, consolidated layer is on them.

In this instance, this one-pound batch of 5/16″ stars used 6 ounces of the star prime.

Note: The above process is actually the beginnings of a simple, hand-rolled, round star production method. In a future article I’ll use 1/8″ zinc stars as the cores upon which to roll some round charcoal stars. These zinc stars make easy-to-handle, dense star cores for this procedure.

Then I spread the stars out onto a drying screen to dry in the warm air, or to be put into the drying chamber detailed in the Project Plans on the Skylighter website.

For purely scientific reasons, and not at all because I was impatient to see these babies in action, as soon as the stars were dry, which took about a week in the open air, or a few days in the drying chamber, I took a few of them out and fired them out of the star testing gun. Man, they are purty!

Note: the 5/16″ stars, which ended up being about 3/8″ including the prime, worked well in the 1/2″ star-gun tube, and required a flat 1/8 teaspoon-full of FFG sporting grade black powder to lift them. I also have some 1/2″ stars which work well in the 5/8″ tube, and require a heaping 1/8″ teaspoon of the lift powder.

Since cut stars may not drop smoothly into the star-gun tubes because of their edges and corners, I use a thin dowel to push them down into the tube and to make sure they are seated against the lift powder.

In the next blog article, I’ll be using these stars to make a really nicely performing 4″ plastic ball shell. I hope you can hang around for it.

See ya then, and Stay Green,

Ned

14 Great Cut Star Formulas

How to Make Cut Firework Stars in an Hour or Less

Cut stars are the simplest and easiest stars to make. They are generally also the cheapest. One can make large quantities of cut stars in a short space of time. Cut stars can be made with or without special tools or equipment. Cut stars can be used in:

• shells
• rockets
• mines
• fountains

Small cut stars can also be used as cores for making round stars. These are typically small cubes with sides about one eighth of an inch in length. Cut stars are not the best choice for Roman candles. For those, round or cylindrical (pumped) stars are better.

There are a variety of different ways to make cut stars. Some use a frame specifically designed for cut star making. Other simpler ways dispense with frames entirely. Both methods are discussed here.

The materials needed to make cut stars are dependent on the formula used and on the formula of the prime if a prime is used. The most popular type of prime used is meal powder, which is black powder in fine powder form rather than in granules. It is generally recommended that stars be primed. An exception to this rule is chlorate stars, which usually do not need priming, and are rarely primed with black powder.

Some kraft paper is needed to line certain types of star frames. One gallon zip-lock bags are useful if one is mixing just one or two pounds of star mix.

Another useful material is a roll of waxed paper, the type normally found in the kitchen.

The barest minimum one needs to make cut stars is:

• mixing bowl
• mixing spoon or spatula
• rolling pin (if a frame is not used)
• knife
• mallet
• scale for measuring quantities

The above assumes that a flat, smooth working surface is available. Do not use a knife with serrated edges. Preferably get one large enough to make each cut with a single cleaving (as opposed to slicing) action. A useful addition to the above is a drying screen that need be nothing more than a window screen. Stars dry out a lot quicker on a drying screen than if one just places them on a flat surface. Use rubber gloves as general hand protection against toxic chemicals. Gloves are essential if one decides to knead the star mix by hand.

Alternatives to Knives Some makers of cut stars do not believe in using something with as sharp an edge as a knife and prefer to use a blunt blade made from a sheet of metal or a tool that is used for plastering walls. You can try these options if you prefer. However, knives with sharp edges do work just fine.

A 20-mesh mixing sieve is nice to have when mixing the dry ingredients. Although most firework makers consider a mixing sieve to be absolutely essential, I beg to differ with them. A good mix can be got without a sieve but normally takes longer. Sieving can also cause certain very fine powders such as lampblack and bismuth trioxide to agglomerate into tiny balls.

A star frame (or set of frames) is a good investment if you are planning to make large quantities of cut stars. The process is quicker and more accurate with a good star frame.

Before describing the steps in making cut stars, an important consideration needs to be borne in mind: Small is beautiful.

Whether you are a beginner or a pro the clever way to make cut stars using a new untried formula is to make very small quantities in the beginning. These small quantities of stars are tested to determine how well the stars perform before larger quantities are used. One way is to make a small quantity of star mix and burn it in a small lance tube. Another way is to make a very small batch of stars without a star frame, then dry and test these. This method gives a better test but takes a lot longer because the stars need to dry out before use.

Measuring Dry Materials All dry materials are measured by weight, not by volume. Thus if the formula you are using calls for five parts of potassium nitrate and two of sulfur, this could be translated as five grams of potassium nitrate to two grams of sulfur, rather than five teaspoons of potassium nitrate to two teaspoons of sulfur. The gram measurements are given just as an example. Five ounces of potassium nitrate would be mixed with two ounces of sulfur, five pounds with two pounds, and so on. Mixing Dry Materials As discussed above, dry mixing can be done with or without mixing sieves. The goal is to have all the ingredients intimately blended with each other. It pays to do a proper job at this stage of cut star making. Many have made the mistake of assuming that one can compensate for inadequate dry mixing by just taking a bit longer mixing the ingredients when wet. Sometimes this works; other times it does not, depending on the formula used. It is not uncommon to discover small pockets of unmixed dry chemicals in a wet mix that has been mixed for some time. This is a sure indicator that the materials were not mixed properly when dry. Adding Solvent (Water or Other Solvent) Before adding the solvent, you should put aside some of the dry material. This can be used for dusting the surface that the dampened star composition will be cut on. It can also be used in controlling the consistency of the wet mix, especially in the all-too-common situations when too much solvent is added. A good amount to be set aside is about one quarter of the dry mix. This amount can be reduced eventually with more practice.

Weight vs. Volume Is there a way to convert weight into volume and measure by volume rather than weight? No, not really. The thought behind converting weight to volume is influenced by the idea that if one knows the density of a material one can easily convert its weight to volume or its volume to weight. This is true of solid pieces of material but not of material that has been reduced to powder or granular form. This does not have a true density because the material is actually a mixture of the material and air. In place of true density such a material has what is called bulk density. Bulk density is a density measure of solids that have been divided into small pieces or crushed into powders. Thus potassium nitrate in powder or granular form has a bulk density, as does sugar and salt. Black powder has a bulk density, and so does instant coffee and corn flakes.

Add the solvent by slowly pouring or spray-misting it into the dry mix while stirring continuously, or working it in with your hands. Both these actions are important to ensure good mixing. If the solvent is added too quickly or the mix not stirred thoroughly, separation of the ingredients can occur. Here lighter materials will tend to float on the surface of the solvent and soluble materials can be dissolved and separated from surrounding materials.

The trick in making good cut stars is to ensure that the wet mix is neither too dry nor too wet. The consistency should be that of putty or modeling clay. To get to this point, slowly add the solvent while continuing to stir the mix. If too much solvent ends up being added, add some dry material to get the mix back to its proper consistency.

Cut stars are often primed just after they are cut. Many prefer this method because it simplifies the operation. You do not have to prime your cut stars at this stage. You can prime them after they have dried.

So much for the general discussion on cut stars. The above is put into practice by actually doing a cut star project. Here is how you go about it.

Weigh out the dry ingredients to yield approximately one pound of dry mix.

Mix the dry ingredients by first sieving (if you have a sieve) and then by stirring them together in a bowl. When the dry ingredients are thoroughly mixed place about 75% of them on a one gallon zip-lock plastic bag. A one gallon freezer bag is ideal. Keep the other dry 25% to one side.

Measure out the solvent used by weight. If you know its density you can measure it by volume and then convert this volume to weight. A rough guide to the amount of solvent needed is between five and ten percent of the weight of the dry ingredients.

Add the solvent to the dry materials in the zip-lock bag.

Knead the materials inside the zip-lock bag by squeezing them with one or both hands as shown in Figure 1.

When the material inside the bag is thoroughly mixed take out a small handful for testing. Close your hand around it, and squeeze it. It should hold its shape, and no water should come out between your fingers. If the sample crumbles add more solvent. If it is too wet add some of the dry ingredients you set aside. Note the sample shown in Figure 2 is a bit too wet.

Star frames enable you to make cut stars more accurately and can yield stars that are physically stronger because you are able to compress the mix more. However, you can make adequate cut stars without a frame by doing the following:

Take the mix out of the plastic bag and place it on some wax paper on your working surface (table, workbench, etc.).

Knead the mix with your hands and form it into one solid lump.

Press down on the mix with the palms of your hands until it forms a large patty about an inch thick.

Roll the mix flatter with a rolling pin until you reach the desired star thickness.

One way you can more accurately get a consistent thickness is to get two strips of wood the thickness you desire and place them on the work surface spaced apart about two inches less than the length of the rolling pin. Place the lump of mix midway between the two strips of wood. Then flatten the lump first with your hands and then with the rolling pin running along the two strips of wood.

Some hardware stores sell square strips of wood in sizes like 1/4″ and 3/8″ often in the wooden dowels section.

When you have flattened the mix to the required thickness cut the stars according to the instructions in step 4.

This section describes how to use the star frame shown. This star frame has a compression lid that enables you to press the mix by putting pressure on the lid. Star frames that differ from this design will require slightly different methods. But the same basic principles apply to all star frames.

Cut two pieces of kraft paper into squares to fit the inside of the star frame. Remove the lid from the frame and place one of the pieces of paper inside the frame so that it lines its bottom. I have used very thick kraft paper here, almost as thick as thin cardboard. If you are using thinner paper then use two sheets to line the bottom.

Remove the material from the plastic bag and spoon it into the star frame. Disperse the material evenly around the frame using either a spoon or a spatula as shown in figure 3. When the materials are properly dispersed, place the other square of kraft paper on top of the material.

Replace the lid of the frame and press down on the frame by leaning on it as shown in Figure 4.

Hammer on the lid with a rubber mallet to compress the material even more as shown in Figure 5.

Remove the lid from the frame and then separate the frame from its bottom. The star mix will be compressed to a flat plate as shown in Figure 6.

Slide the slab of star mix onto a cutting board as shown in Figure 7.

Fireworks makers have their individual preferences when cutting cut stars. Some prefer to immediately slice the slab into strips; others prefer to mark out the strips as equally-spaced lines on the slab before cutting. This second method helps you to get better consistency in star sizes, and is the method shown here in Figure 8.

Continuing the strip marking method, mark the slab into cubes before cutting as shown in Figure 9.

Finally, cut into individual cubes as shown in Figure 10.

The above method describes using the star frame with about a pound of mix. This is about enough to make the single slab shown. Using more mix, such as four to five pounds gives you a brick rather than a thin slab. Here you cut the brick into slabs first. This procedure is described in more detail in a later section.

For most applications, it’s best to prime your stars. This section describes the preferred method on how to prime stars. It is the “preferred method” because it is the safest method. It is called the “diaper method.”

Place the stars in the middle of a large sheet of paper as shown in Figure 11.

Note: Newspaper is often used for this purpose.

Pour some prime mix over the stars.

Pick up one corner of the sheet of paper and move it towards the other corner, rolling the stars over in the prime mix in the process as shown in Figure 12.

Repeat this process with the opposite corner and then with the two other corners until the stars are thoroughly coated with prime.

Having got this far, taking great care to do everything properly, it seems a crying shame that one’s cut stars can end up being a dismal flop. Unhappily they can, due mostly to that very common human weakness – impatience. Having made presentable looking stars, you now want to try them out. It can take days to properly dry out stars and there is the natural tendency to want to speed this process up.

Most speed-up drying processes have a tendency to degrade the performance of the stars or dry them on the outside while trapping moisture or solvent on the inside. Others are downright dangerous! Do not try to dry stars near an open fire, in an oven, nor in a microwave oven. Do not dry them in direct sunlight, which can trap moisture inside (”driven-in” moisture). Ultraviolet radiation and heat from direct sunlight has caused some star mixes to spontaneously ignite!

The best way to dry stars is to place them on a screen in a shady, well-ventilated area outdoors. What you want is air moving over the stars; heat is not necessary.

Warning: Locate your drying stars in a safe place. If they were to ignite spontaneously, where would you want them to be? The best practice is to try and anticipate what the worst case situation would be and take preventive measures accordingly. I cannot overemphasize this enough: drying stars can and do self-ignite!

Figure 13 Stars Drying on Window Screen

How Not to Dry Stars Do NOT place stars in a microwave oven Do NOT place stars in a conventional oven Do NOT place stars in toaster oven Do NOT place stars near an open fire Do NOT place stars on a hot surface Do NOT blow hot air on the stars Do NOT place stars in direct sunlight

Patience is the key to ensuring that your stars dry properly. Typically stars take a few days to dry out. Some large stars that absorb a lot of moisture while being made can take a few weeks of drying before they are properly dried.

How do you know when the stars are dry and ready for use? One way of finding out is to weigh the stars. The total weight of the stars plus any left over dry material and pieces of star scrap should weigh approximately the same as the original dry mix did. While some might put a lot of faith in this method, the real world dictates that this will only get you into the ballpark. Inaccuracies are inevitable because some material will always be lost in the star making process. Another factor is that some pyrotechnic mixes tend to retain a small percentage of the solvent used. A typical example is black powder that can retain between 0.3% and 1% of water. Commercial black powder that I have tested has contained between 0.4% and 1.2% of water.

The above two inaccuracies work against each other and it is possible that in certain circumstances they cancel each other out.

A simple way you can test a star to find out if it is dry or nearly dry is to try and crush it between your thumb and forefinger. If the star crumbles easily it is far too wet. If it crumbles only with difficulty or does not crumble at all, the star is either dry or close to being dry.

If your stars have passed the second test, the next step is to place a star on a hard surface and hit it lightly with a hammer until it breaks. Do NOT use a steel hammer as this can cause sparks that could ignite the star. Use a mallet or a hammer made from leather, brass, aluminum, rubber, or plastic. Note than plastic hammers are often steel hammers that are encased in plastic. These are fine to use because the steel cannot come into contact with anything else.

If you tap your star with a hammer and it just crumbles to powder it is probably still moist. Dry stars are usually rock hard and rarely crumble easily. An exception to this rule is if you have a mix with large particles and insufficient binder.

The next test is to actually light a star (or number of stars) and see how they perform. You can perform a quick “ground” test by placing the star on a non-combustible surface such as a brick, stone, or cinder block and lighting it. For safety’s sake do not use a regular match or cigarette lighter to light the star. I learned this the hard way when I literally burned my fingers. You can buy a variety of extra-length matches that are three inches long or even longer. Some charcoal lighters have a short barrel that keeps the flame a distance of about six inches (or even longer) away from one’s hand. These are another good choice. They are inexpensive and are often sold in supermarkets.

Lighting a star on the ground can tell you if the star is dry enough, but does not give a clear picture as to how the star will perform when flying through the air.

The ultimate test for your stars is, of course, in the actual device you are using them in. However, it’s good to know up front if you stars are likely to perform properly before committing a lot of time, effort, and perhaps money in making a lot of stars and loading them into your rockets, shells, mines or whatever else you are using them for. An easy way to perform such a test is to use a star gun. You can either purchase one or make your own. More information on testing and using star guns can be found in the Skylighter Project Plans:

Some fireworks makers prefer to prime their stars after they have dried out. Others choose to prime their stars only if the star gun tests or actual applications in devices such as shells demonstrate the need for prime. Fortunately it’s an easy matter to prime dry stars.

The trick in priming dry stars is to coat them with just enough solvent to cause the prime to stick to the star. This is rarely achieved by dipping the stars in the solvent. The best way to thinly coat the stars with solvent is to spray the stars with a misting bottle and using a fine mist. It’s best to adjust the nozzle of the sprayer and test it on something other than the stars before spraying the stars. The wet stars are then primed as described before in step 5 and then dried following the normal drying procedure. As you are only drying prime, the drying process should be over quite quickly.

Cut stars are typically used in shells, rockets, mines and fountains. You can find out more about these by following these links:

Sizes of cut stars used in round shells

How to use cut stars in mines

One very important safety rule when making fireworks is to clean up after you have finished your project. The preferred way to clean up scrap star mix is to burn it. This includes scrap that has stuck in small quantities to pieces of kraft paper, etc. Ensure that any burning is done in a safe manner where all the necessary precautions are taken to ensure that nothing else can be accidentally burned in the process.

The “Small is Beautiful” slogan applies especially in safety. The larger the amount of materials you are working with the less safe you are. Larger amounts mean more chance of having an accident and the greater the consequences of the accident. However, there are other issues you need to pay attention to. Large amounts of wet star compositions can, depending on the circumstances, heat up and unpredictably create a fire. This has happened to more than one very experienced fireworks maker, resulting in severe-to-fatal burns! Don’t let it happen to you.

Safety also applies to storage. Never store your stars or any other fireworks mixture in glass containers. Use paper, cardboard, or plastic bags. Do not mix different types of stars when storing them. “Small is beautiful” also applies to storage. The larger the quantity stored, the less safe it is. Also, ten pounds of stars stored in ten one-pound containers is safer than ten pounds stored in a single larger container.

It goes without saying that your stars must be stored in a place where they cannot be ignited from any source of ignition such as an open flame, a space heater, etc. Regardless of whether you have a BATFE license or not, you are legally required to store your stars in a magazine which conforms to BATFE regulations.

The just-described project showed you how to make cut stars using a particular type of star frame or no frame at all if you chose the method described in step 2. The star frame used in the project above had a bottom plate and a lid. Some star frames come with neither. Here are pictures of the star frame used in the project and some others.

Shown in Figure 14 is the star frame described in the project. In the top left-hand side is the lid, followed by the frame and its bottom plate.

Shown in Figure 15 is the “baby brother” of the star frame shown above. This star frame is smaller and its lid and bottom plate are identical.

This is about the simplest star frame one can get. It has four sides with no lid or bottom plate.

The star frame shown in Figure 16 is very simple and easy to make. Because it has no bottom plate or lid it requires a slightly different technique in making stars. One such technique is to cut two strips of kraft paper the internal width of the frame (5.5″) and about 20 inches long.

Lay the pieces of kraft paper perpendicular to each other across the top of the frame so that their centers are in line with the center of the frame.

Press the centers of the pieces of paper down into the frame and scoop the star mix into the frame.

When all the mix is in the frame press it down so that it is flat as possible and then fold the pieces of kraft paper that are sticking out of the frame over the top of the mix.

Get a piece of two-by-four about eight to ten inches long and press down hard on the top of the mix, moving the two-by-four all over the frame.

Tap down hard on the mix with the two-by-four to compress it as much as possible.

Grab the frame and lift it so that the paper-wrapped “brick” of star mix slides out of the frame.

Pull the paper away from the sides of the brick and cut it into slices like one would do with a loaf of bread. Dice the slices into cubes as described in the project.

Making & Testing High-Powered Black Powder

Black powder (BP) is an almost ridiculously simple pyro ingredient. Mostly just three chemicals, blended together in simple ways, but producing wonderful results. Black powder exemplifies for me the endless learning, experimentation, and creativity that fireworking holds for us. If so much fun can be had with BP, imagine what else fireworks-making has in store for you.

In this article I’ll be writing about two basic skills:

1. How to make black powder using 4 basic methods, ranging from the use of only two simple screens, through the use of a star-roller, hydraulic press, and/or a ball-mill.

2. How to test various black powders to compare their power, and to determine how much to use when lifting a typical fireworks aerial shell.

I hope this article will be useful for both the novice fireworker, and for the most experienced one.

Have you ever taken the covering off of the bottom of an aerial shell and observed the black granules which are used as the shell’s “lift powder?”

Black powder is perhaps the most basic and useful of all fireworks ingredients. It is used to lift shells, comets, mines, Roman candle stars, and as a base-composition in some rockets and many other fireworks components and devices.

Here is the definition of black powder taken straight out of the The Illustrated Dictionary of Pyrotechnics (Skylighter #BK0043):

For the sake of this article, at least, let’s define high-quality BP as that black powder which will adequately serve the needs of the fireworker, and which comes close to, or exceeds, the quality and explosive power of commercially available black powder. Goex brand is a well-known, and often referred to, example of commercial powder.

First of all, didn’t we say, “Hey, I’d like to learn how to make fireworks”?

You can buy some types of black powder. There are two types available, sporting and blasting. The sporting grades of BP, made by Goex and others, are readily available from some gun and sporting goods shops, and some online sources. These are the “Fg, FFg, FFFg, FFFFg, ” etc. grades listed in the black powder grain size charts.

The blasting grade, “A” powders are most frequently used in fireworks. 2FA, 4FA, and Meal-D are the sizes we need the most. (See the article on black powder sizes and grades Size Does Matter in Skylighter Fireworks Tips #44.) They are available only to holders of a BATFE explosives license.

If you can find BP at your local gun shop, it usually retails for $16 – $24 per pound. Beginner shell makers can easily use more than 50 pounds of 2FA per year. That’s about $1,200 at retail! It doesn’t take long, buying commercial BP, before you start asking yourself, “Self, ain’t there a less expensive way?”

Even if one has the BATFE license to buy commercial 2FA in bulk (50 or 100 lbs at a time), the current price of it is $7-8 per pound.

So, economics, practicality, availability, and the pride of actual fireworks-making, all eventually make it inevitable that most pyro-hobbyists will make their own BP. And the good news is that it is Federally legal to make it yourself, without an ATF license. But, check your state and local laws first to make sure you can comply with them as well.

Many would argue that the very first, important step to learning the art of fireworking is tackling the skill of making high-quality black powder.

Typically, these are the key variables in making powerful, high-quality BP:

#1: The quality of the chemicals and the type of charcoal (wood species) that is used. Willow charcoal is often being referred to as the wood of choice for BP charcoal. I use spruce/pine as the wood that I turn into homemade charcoal. (This subject is discussed in the Making Charcoal article.) I’ll be comparing BP made with this pine charcoal, with that made with commercial airfloat charcoal.

#2: The method used to pulverize and intimately mix the ingredients. Screening through a fine-mesh screen or ball-milling can be employed. (This subject is thoroughly explored in Ball Milling 101.)

#3: How the mixed ingredients are consolidated and granulated.

#4: The size of the granules, especially with BP that is made into pucks that are broken up (corned).

I have played with several methods of making BP. Now I’m going to make black powder in four of those ways:

- Pressing BP pucks and breaking them up. (This method has been detailed in Fireworks Shells in 2-1/2 Days – Part 2 and Fireworks Shells in 2-1/2 Days – Part 3.)

- Coating the BP onto rice hulls. (This method was detailed in Fireworks Shells in 2-1/2 Days – Part 2.)

- Ball-milling the composition, wetting the BP with red-gum and alcohol, and granulating it through a 4 mesh screen.

- Simple screening of the chemicals through a 100 mesh screen, and using the red-gum/alcohol granulation method.

I ball mill four 20-ounce batches of mill-dust BP, two batches using pine charcoal, two more using commercial airfloat. Each batch has 15 ounces of potassium nitrate, 3 ounces of charcoal, and 2 ounces of sulfur. I run the ball mill for 2 hours for each batch. I end up with 40 ounces of pine charcoal mill-dust, and 40 ounces of commercial charcoal mill-dust.

(Mill-dust is the term that is used for BP as it comes straight out of the ball mill, before any granulation.)

I take 16 ounces of the pine charcoal mill-dust, add 1.6 ounces of water (10%) to it, and thoroughly incorporate the water into the powder with my gloved hands. Then I further incorporate the water with a screen colander. I press 1/8″ thick pucks with that powder. I have found that if I apply about 1600 psi of pressure on the pucks when I press them, that they are as solidly consolidated as they are going to get. I put the finished pucks into the drying chamber to dry.

I do the same with 16 ounces of the commercial charcoal mill-dust.

(I have found that it is quite easy to break the pucks up a bit by hand while they are still damp. This makes it easier to granulate them later on.)

Third Step
I take 16 ounces of the dry pine charcoal mill-dust, add 0.8 ounce of dextrin (+5%) to it, screen it to thoroughly incorporate it, and coat that BP onto 2.4 ounces of rice hulls in the star roller (7/1 ratio of BP to rice hulls). (See Firework Shells in 2-1/2 Days – Part 2.) I put the coated hulls on screens and into the dryer. Although puffed rice cereal can be used in this process, rice hulls make more durable grains.

I repeat the process with 16 ounces of the commercial charcoal mill-dust.

I take 8 ounces of the dry pine charcoal mill-dust, and dampen it with 1/3 cup of denatured alcohol (from Home Depot) which has 1/10 ounce of red-gum (about 1% of the mill-dust weight) dissolved in it. I slowly add enough additional alcohol to the mill dust, only as much as necessary, to end up with a nice, putty-like “dough ball.” Then I granulate that dough-ball through a 1/4″ (4 mesh) screen onto a kraft-paper lined tray for drying.

I repeat the process using commercial charcoal mill-dust.

Warning: Working with alcohol or any other solvent that puts a lot of fumes into the air, I do so outdoors so fumes cannot collect and be ignited, and I wear a mask-respirator to avoid breathing the fumes.

I simply take 15 oz. of potassium nitrate and screen it through a 100 mesh screen. If all of it won’t pass the screen, I mill it a bit in a small coffee grinder until it will pass the screen.

Warning: I never mill anything but individual chemicals in the coffee grinder. I use one coffee grinder only for oxidizers, and a different one for fuels. I thoroughly clean it after using it for one chemical.

Then I combine that 15 oz. of potassium nitrate with 3 oz. of pine airfloat charcoal and 2 oz. of sulfur, and pass them twice through the 100 mesh screen to thoroughly mix them.

This 20 oz. batch of BP chemicals is then wet with about 3/4 cup of the denatured alcohol which has 0.2 oz. of red-gum dissolved in it. More alcohol is added as needed and the putty is granulated as in Step 4 above.

I do the same for a similar batch using the commercial airfloat charcoal.

Many of you are now saying, “Aw, he’s never gonna get a useful BP with that simple screening method. It has to be ball-milled.” You just wait.

All of the powders produced above are left in the drying chamber until they are completely dry. (Skylighter’s project plans show you how to make and use a drying chamber.)

Once the powders have dried in the drying chamber for a day or two, I process them in various ways.

Processing black powder pucks (see how to granulate black powder pucks.)

With the pine charcoal pucks, I end up with 10.7 ounces of the 2FA, and 1.75 ounces of the 3FA. (In reality, commercial 2FA powder contains grains from 4 to 12 mesh, but my 2FA consists of only the coarser grains.)

With the commercial charcoal pucks, I ended up with 10.15 oz. of 2FA powder, and 2.05 ounces of 3FA.

Note: I don’t really like the process of pressing all these pucks, and then crushing and granulating them. It’s a painstaking, time consuming, and messy process. On the other hand, it is nice to end up with such hard, durable grains, which are practically indistinguishable from commercial black powders.

After dumping the BP coated rice hulls from the drying screens into a rectangular tub, I then simply screened them on my 12 mesh screen to sift out the fine BP grains and dust. There was not a whole lot of that, but I wanted to end up with just the coated hulls.

With the red gum/alcohol granulated powders, I dumped them from the drying screens and forced them through my 4 mesh screen to break up the larger clumps. Then I screened that powder on my 12 mesh screen to remove the fines and dust, ending up with nice, hard grains in the 4-12 mesh size.

Coating the rice hulls and processing the resulting grains is relatively easy, and the alcohol/red gum granulated powder is probably the easiest to produce. It is a bit more expensive to make, though, since the red gum powder and alcohol cost a little more than dextrin and plain water.

So, now I have my 10 homemade powders to compare with each other. I also have some German Wano 2FA powder (equivalent to Goex 2FA) which I screen and separate into 4-8 mesh and 8-12 mesh powders, as I did with the homemade powder made from pucks.

• Pine charcoal 2FA
• Commercial charcoal 2FA
• Pine charcoal 3FA
• Commercial charcoal 3FA
• Pine charcoal BP coated rice hulls
• Commercial charcoal BP coated rice hulls
• Pine charcoal, ball-milled BP, processed with alcohol and red-gum
• Commercial charcoal, ball-milled BP, processed with alcohol and red-gum
• Pine charcoal, simply screened BP, processed with alcohol and red-gum
• Commercial charcoal, simply screened BP, processed with alcohol and red-gum
• Wano 2FA
• Wano 3FA

Now I’d like to test these 12 BP’s and compare their relative performances.

So far, all of this is very interesting information, but, quantitatively, it does not tell me a whole lot that is useful for me in making fireworks.

I have some big questions I’d like answers to:

• To what extent does the type of charcoal affect the power of the BP?
• Consolidated and granulated using 4 different methods, how much variation in the BP’s power will result?
• How do these homemade BP’s compare in power with commercially produced powders? How can this be tested and quantified?
• How much should I use of one of these BP’s to lift an aerial shell?
• How do the various methods of production compare as far as expense and labor? Are some methods significantly easier than others for the manufacture of BP?

I have to admit that the process I’m about to describe is where my creative juices really start flowing in this hobby. Being curious about something, thinking about it, doing some experimenting, pondering the results, and coming to some conclusions that are useful in my future activities–that’s what this is all about for me.

We have quite a few variables in the above information when it comes to choosing how to make powerful BP and how to use it in our pyro projects.

I want to design an experiment to compare black powders which incorporate these different variables, in order to know how each of those variables affects the BP’s power, and to be able to determine which materials and techniques are preferable when making my BP.

I have my 12 different types of black powder sitting in front of me. Now I’ll test them in various amounts, lifting dummy shells, to compare their relative performances, and to find out exactly how much of each of them to use when lifting an actual fireworks shell.

In years past there has been a “game,” played at the Pyrotechnics Guild International’s annual convention, called “pyro-golf.” Folks brought samples of their prize black powders, and a fixed amount of each was used in a mortar to shoot golf balls into the air. The flights were timed, and the longest flight time would be declared the First Prize black powder. This is a good method for comparing the power of different powders.

Homemade powders could also be compared to commercial BP’s at the same time. Usually the homemade powders outperformed the commercial ones by quite a sizable margin.

There are other ways to compare black powder performances, but I like the golf ball test because it duplicates the real-life application of using black powder to lift aerial shells.

For testing my 12 BP’s, I’m going to use my version: “Pyro-Baseball.” With “Pyro-Baseball,” I use baseballs and a 3″ mortar to simulate the lifting of 3″ spherical fireworks shells. Baseballs are just the right size and weight. They save me the time, expense, and hassle of having to build actual dummy shells.

For my tests, I’m using a one-piece, HDPE (high-density polyethylene) “gun.” Whichever gun you use, it is a good idea to use the same mortar for all of the comparison shots. This will minimize variations from one test to another.

On page 140 of The Best of AFN II (BAFN II) are some charts showing recommended BP lift amounts for various types and sizes of shells. Table 1 indicates that, for lifting a 3″ ball shell, 0.6 oz. of FFg, or 0.75 oz. of 2FA would be appropriate amounts of commercial lift powder.

And, on Page 17 of the PGI’s Display Fireworks Operator Certification Study Guide, one can find a nifty table that shows the typical (desired) heights that various size fireworks shells ascend to before bursting. This table shows that a 3″ fireworks shell would rise to about 300 feet and then burst.

That’s good information to have. Using about 0.6 to 0.75 ounces of my Wano BP ought to send one of my baseballs up to about 300 feet. I can weigh that amount, drop it down into the bottom of a 3″ mortar, insert 4″ of visco into the fuse hole at the bottom, drop a baseball into the gun, and light ‘er up.

But, how do I know if the ball actually ascends to 300 feet before it peaks out (at apogee) and starts to descend? One simple physics equation is all that is necessary to figger that out. If you drop an object and time its descent to the ground, the distance the object has fallen, in feet, is given by the equation, Distance = 16 x time x time (16 x time squared), when the time is measured in seconds.

For example, if I fire my baseball, and start a stopwatch when its flight peaks out at apogee, and then stop the stopwatch when the ball hits the ground, I’ll be able to read the time it took the ball to fall to the ground from that peak. Let’s say that my stopwatch indicates a time-of-fall of 4.18 seconds.

To see how high the baseball was when it started to fall (at apogee), all I have to do is multiply 16 x 4.18 x 4.18 and I get a height of 279.55 feet. That’s pretty close to my desired 300 feet. So I know that using the amount of lift powder that I used, or maybe just a tad more, would be a good quantity of that BP to use in the future for this size and weight shell.

This is what I’ll be attempting to determine with each of the 12 experimental powders. Once I know those amounts for each powder, I’ll then be able to compare their relative powers with each other. I’ll tabulate that info and have some very useful results and conclusions. Just what I was looking for to begin with.

Note: An interesting relationship that I’ve noted during past tests is the amount of time a dummy shell takes to rise to apogee after being fired from the mortar, compared to the time it takes to fall to the ground. I’ve noted that it takes a spherical dummy shell approximately half the time to rise to apogee that it takes the shell to fall to the ground from apogee.

Another way of saying this is that, of the total flight time from launch of the dummy shell from the gun to it hitting the ground, one third of the flight time is spent rising to apogee, and two thirds of the time is spent falling to the ground from the apogee.

So, if I use various amounts of a lift powder and time the baseball’s flight from the apogee to the ground, adjusting the powder amounts as I go along, until that time of fall equals 4.33 seconds, then I’ll know exactly how much of that powder to use again to duplicate that height. 300′ = 16 x 4.33 x 4.33.

If I want a slightly higher flight for a shell, for example one with a long burning willow star shell, then I’d use a bit more powder.

So, I go out to my shoot site with my lovely assistant and all my testing materials: BP’s, scale, spoon, paper cups, notebook, pen, baseballs, mortars, visco, anvil-cutter (I never cut fuses with scissors, only with razor blade anvil-cutters), chairs, table, stopwatches, sunglasses, camera, re-bar, and duct tape.

No, she didn’t really try to catch the balls. She had to man (woman) one of the stopwatches instead.

The mortar was taped to a piece of rebar driven into the ground, angled away from us, and the ammunition was prepared. I had previously drilled a small fuse hole near the bottom of the mortar.

I had prepared some charts in advance to take notes for each powder test. The vertical axis represents the time of fall in seconds, and the horizontal axis represents ounces of black powder in 0.05 ounce increments. I drew a horizontal line at 4.33 seconds since that time of fall represents a height of 300 ft., which is what I’m shootin’ for.

Then, it was just a matter of starting to fire baseballs with measured amounts of one of the experimental BP’s, such as the one in the above chart: ball-milled, commercial charcoal, alcohol/red-gum granulated. We used two stopwatches, recording the total time of flight, and the time of fall from the apogee to the ground.

Judging the exact apex of the flight can be a bit tricky, since there is a second before the apogee where the flight up really slows down, and there is also a bit of time after the apogee before the ball really starts to pick up speed. But, we just did the best we could. It’s probably a bit more accurate to use a time that is 2/3 of the total flight time, from lift to landing.

Warning: After each baseball firing, there may be hot sparks remaining in the mortar. I am careful to wait a bit before reloading. Then I insert the visco fuse, drop the next portion of BP in, and then carefully drop the baseball in. I avoid getting any body part over the mouth of the gun when doing this, regardless of whether I know the fuse is lit.
A baseball fired at this speed could easily kill a person or remove a hand or arm.

I wanted to start with a small amount of the powder, gradually increasing it until I started to get flights that were a bit too high. I figured that would give me the spread of data which I could use to determine the right amount of powder for a 300’ high flight. The following is a listing of the amounts of this one particular powder that I used, and the resulting flight times that we recorded.

Ball milled, commercial charcoal, red-gum/alcohol granulation

Amount of BP	Time from apogee to ground	Total flight time
0.25 oz.	2.06 seconds	3.28 seconds
0.40 oz.	3.50 seconds	5.69 seconds
0.50 oz.	4.56 seconds	7.22 seconds
0.45 oz.	4.18 seconds	6.62 seconds

Below is a computer-generated graph of the data above.

When these coordinates were entered into the graph, a couple of things became obvious. There is a linear relationship between the amount of lift powder that is used, and the corresponding flight time.

This graphed line, if extended down to the bottom of the chart, points to an amount of BP which would not even get the ball out of the gun, about 0.05 ounce in this case.

That graphed line crosses the 4.33 seconds/300′ line, between 0.45 and 0.5 ounces of the BP.

Indeed, when the average time from apogee to the ground, is divided by the average total flight-time, the time from apogee to ground is about 2/3 of the total flight time from lift to landing.

With this powder, I’d use 0.5 oz. to reliably lift a 3″ ball to 300′.

We did this with each powder, firing baseballs about 40 times into the air.

Repeating the tests described above with each of the 12 BP’s, I was able to determine the optimum amount of each powder for lifting a baseball to 300′.

0.30 oz.	Milled pine charcoal, red gum/alcohol
0.35 oz.	Milled pine charcoal, pucks sized to 3FA
0.40 oz.	Milled pine charcoal, coated on rice hulls
0.45 oz.	Milled commercial charcoal, pucks sized to 3FA
0.50 oz.	Milled commercial charcoal, red-gum/alcohol or on rice hulls
0.55 oz.	Commercial Wano BP, 3FA
0.60 oz.	Commercial FFg recommendation from BAFN II chart
0.75 oz.	Commercial 2FA recommendation from BAFN II chart
0.75 oz.	Commercial Wano BP, 2FA
0.75 oz.	Milled commercial charcoal, pucks sized to 2FA
0.75 oz.	Milled pine charcoal, pucks sized to 2FA
0.75 oz.	Simply-screened, pine charcoal, red-gum/alcohol
0.90 oz.	Simply-screened, commercial airfloat charcoal, red-gum/alcohol

Note: It was almost difficult to use a small enough amount of the pine-charcoal/red-gum-alcohol powder. A third of an ounce is a mighty small amount of lift powder.

To what extent does the type of charcoal affect the quality of the resulting black powder?
Homemade pine charcoal produced powder that was marginally better than that produced with the commercial charcoal, but both can produce BP’s that far outperform commercial black powders.

How did the 4 methods of processing/granulating the BP’s compare when the resulting powders were tested? All three methods that employed ball-milling produced powders that were very comparable. The method that used simply-screened chemicals produced BP that, while not as powerful, was very functional in amounts comparable to commercial 2FA.

How does the size of the granulation of pressed pucks affect performance? For these 3″ dummy shells, the finer 3FA (8-12 mesh) granulation far outperformed the coarser 2FA (4-8 mesh) granulation.

How much lift powder should I use for a shell? The amounts in the chart above indicate how much of each type of powder to use for a 3″ ball shell. These amounts can be dialed in when manufacturing actual fireworks shells. In general, if I were to multiply the recommended amount of lift powder listed in the BAFN II table by 0.6 for the milled, pine charcoal BP’s, or by .75 for the milled, commercial charcoal BP’s, I’d arrive at a good starting amount of homemade lift powder.

How do the 3 methods of processing/granulating the homemade powders compare as far as difficulty and expense? The easiest powder to make is the screened red-gum/alcohol granulated BP, followed closely by the milled red-gum/alcohol BP, and then the BP on rice hulls. Pressing pucks and corning them is significantly more difficult and messy.

The red gum and alcohol make that method slightly more expensive in material cost than the other two methods. Milling requires an up front investment in a machine and milling media. Rice hulls are cheap, so using them does not make that method much more expensive than pressing the pucks. All of the methods of making homemade BP are much less expensive than purchasing commercial black powder.

For my purposes, either homemade or commercial charcoal produces completely satisfactory powder. I really like the ease of production, and the final resulting powder when the red-gum/alcohol method is employed to make BP, so I’ll probably use that method when making lift powder for aerial fireworks shells.

To me, the simply-screened, red-gum/alcohol method looks like the method-of-choice for simple, field-expedient, very functional black powder, and it can be produced without any complex or expensive machinery. This method is ideal for the beginning fireworker.

I think I’ll bring my bucket of baseballs and a couple of 3″ mortars to the next PGI convention, and whoever is interested can take to the field with me to go head-to-head with our prize black powders. May the best pyro win!

Enjoy and Stay Green,

Ned Gorski