How to Make Gold Glitter Comets
IntroductionOne of my favorite effects is a nice gold glitter comet.
This is also one of the easiest and most impressive beginner pyro projects. Make some homemade black powder and one of these simple projectiles, and you are ready to impress the folks around you. And you made it all yourself!
This is also the simplest and most effective rising effect to put on my aerial fireworks shells. The shell is launched out of the mortar and leaves a beautiful glittering gold tail as it ascends skyward. Just as the comet tail burns out, the shell bursts. The rising effect effectively doubles the display time of the shell, and fills the sky all the way from the ground to the starburst. A tail also helps to point the spectators' eyes at the exact spot where the shell is about to break.
Some master rocketeers put these comets on top of their rocket headings. The comet is ignited at the same time as the rocket, and leaves a beautiful glitter tail as the rocket ascends. I'll be detailing this method in a future newsletter article.
It is also very easy to pop a bunch of these little comets out using a half-inch star plate, and put them into a small ball shell like the 4-inch plastic shells. The combination of some color stars and these glitter comets makes a beautiful starburst.
Note: The difference between stars and comets is a subtle one. Typically comets are fired individually, and stars are shot out of a device in a cluster.
I have a favorite gold glitter formula which I have been using for years in both stand-alone comets and as shell tails. Anytime I fire something made with this formula someone is sure to ask me what it was and how they can make it, too. This glitter is a slightly modified version of the Gold Twinklers found in Ofca's Mastering Cut Stars, and in Weingart's Pyrotechnics.
This formula is relatively expensive though, because of the chemicals it uses. There is a much less expensive gold glitter formulation which does not use chemicals which cost as much, but which also produces a beautiful effect. This glitter is a slightly modified version of one called D1.
I'll be using both of these formulae in this project.
The Comet PumpBesides the formulated glitter compound, one tool is essential for pumping comets: the comet pump.
Star Plate and a Variety of Comet Pumps
The black individual comet pump and star plate shown in the photo are treated aluminum. The other pumps shown are aluminum, brass, and homemade, PVC-pipe-and-wood pumps.
It's simple and inexpensive to make a 3/4-inch or 1-inch homemade comet pump as shown above. Start by going to Home Depot and getting the correct size oak dowel, a length of the corresponding size of PVC plumbing pipe, and 3 hose clamps which fit the outside of the pipe. (You can buy ready-made comet pumps from Skylighter. Skylighter pumps are rugged brass or aluminum and will typically last a lifetime. They are faster and easier to use than homemade comet pumps.)
Then cut a 6-inch length of the dowel, and a 5-inch length of the pipe, preferably with either a hand miter box or a power one to insure good, square cuts.
Using a hacksaw, slice about halfway up one side of the pipe, and remove enough of that slice of pipe so that it fits the dowel snugly at the sliced end when the gap is closed.
Sand the rough edges of the pipe and dowel, and make sure one end of the dowel is nice and square and smooth. Either seal this end with polyurethane, or cover it with a disc of aluminum-foil duct tape.
Making a Homemade Comet Pump
Mixing the Comet CompositionThe Gold Twinkler formula is as follows:
|Black powder meal||0.68||5 ounces|
|Atomized aluminum||0.08||0.6 ounces||(Use Skylighter's #CH0116)|
|Antimony trisulfide||0.08||0.6 ounces||(either dark pyro or chinese needle)|
|Sodium oxalate||0.11||0.8 ounces|
|Total batch weight:||7.4 ounces|
The D1 formula is:
|Black powder meal||0.71||5 ounces|
|Atomized aluminum||0.07||0.5 ounces||(same aluminum as above)|
|Sodium bicarbonate||0.07||0.5 ounces|
|Total batch weight:||7.1 ounces|
I'm planning on making one batch of each formula to compare with each other. Therefore I need a total of 10 ounces of the homemade, black powder meal. This will include:
To make the BP meal, I first grind the potassium nitrate in a blade-type coffee grinder, this turns it into a nice fine powder. Then I screen the potassium nitrate through a 100 mesh screen, and then screen all the chemicals together twice through the same screen to thoroughly mix them together.
Then I add 1/2 cup of denatured alcohol to the dry chemicals to form a damp ball of putty, which I screen through my 1/4-inch screen onto kraft paper to dry overnight.
Note: Alcohol fumes are combustible. I dry these granules outdoors to prevent the fumes from collecting and igniting.
Mixing Black Powder Chemicals Through 100 Mesh Screen, and Granulating Dampened Composition Through 4 Mesh Screen
When the black powder granules are dry, I screen them again through a 12 mesh screen or a wire-mesh kitchen colander. I then have a black powder meal which ranges from fine dust up through 12 mesh granules.
To complete the compositions, I split my meal powder batch into two, 5 ounce halves. I then weigh out the rest of my individual ingredients. I don't screen the aluminum or antimony trisulfide, but I do screen the rest of the ingredients for each batch through my 100 mesh screen.
Then I put all the ingredients for each batch into a plastic tub, attach the lid, and shake vigorously to thoroughly mix the ingredients.
Using a small, trigger-operated, garden spray-bottle, I add just enough water to knock the dust down and start to make the composition not quite as free-flowing. I work the water into the powder with gloved hands and by capping the plastic tub and shaking it. Each batch took 0.35 ounces of the water, which is about 5% by weight.
Note: It is a good idea to used bottled, distilled water to dampen compositions containing aluminum and potassium nitrate. This helps to prevent reactions between the two chemicals. One person's tap water might be fine to use, and another's might cause problems.
Ramming Glitter CometsNow it's time to make some comets. I place my comet pump sleeve on my aluminum ramming puck after making sure that the hose clamps are tightened. I place a funnel in the mouth of the sleeve and introduce a weighed amount of the glitter composition into the sleeve.
Then I put the comet pump ram into the sleeve, place the whole shebang on my 6x6x36 ramming post, and I whack the ram with 8-12 blows with my rawhide mallet. At a certain point, the comet will start to feel solidly consolidated.
It's just a matter of slightly loosening the hose clamps, and gently ejecting the comets from the pump sleeve with the ram. I then dry them for a couple of days in a well ventilated, warm area, or overnight in my drying chamber.
Ramming a Glitter Comet
One of the things I want to record is how much composition it takes to form different length comets with the 3/4-inch and the 1-inch pumps. Those results are as follows for both formulae:
|0.4 ounce||1/2-inch long|
|0.5 ounce||5/8-inch long|
|0.6 ounce||3/4-inch long|
|0.7 ounce||1-inch long|
|0.2 ounce||7/16-inch long|
|0.3 ounce||5/8-inch long|
|0.35 ounce||3/4-inch long|
|0.4 ounce||13/16-inch long|
3/4-inch and 1-inch Diameter Comets of Various Lengths
For stand alone comets, I'll press them as long as they are in diameter. For rising shell tails, I'll press them long enough so that they burn out just as the shell breaks (duration of shell timing fuse). I'll be determining the burn time of each length comet in a minute.
Priming the CometsMany folks would say that these comets do not need any priming because they are mostly made of BP meal, which ignites very well all on its own.
But, often pumped stars and comets have a very smooth surface, and I've learned the hard way to avoid assuming they'll light without priming. They might, and they might not. So I prime everything.
Scratch Mix BP Prime Formula
|Potassium nitrate||0.75||7.5 ounces|
|Airfloat charcoal||0.15||1.5 ounces|
|Total batch weight:||10.5 ounces|
I screen the potassium nitrate through the 100 mesh screen, and then screen all the chemicals together through the 100 mesh screen twice to thoroughly incorporate them. Then I put them into a plastic tub, with a lid, and shake them a bit to really mix them well.
Depending on how many comets I plan on priming, I'll take a few tablespoons-full of the dry prime comp, put it in a paper cup, and add enough water to make a thick syrup, like honey. After stirring this a bit with a wooden stick, I use a brush to coat one end of each comet. Then I dunk that end into some FFg sporting grade black powder, or some more of the homemade black powder meal. What I want is a rough, granular surface that will more easily take fire.
I allow the primed comets to dry overnight outdoors, or for a couple of hours in the drying box.
Priming Glitter Comets
Installing the Comets on an Aerial Shell or Rocket HeaderIt is easy to hot-glue one of these comets onto a plastic or paper shell or header. Just put a healthy blob of the glue onto the bottom of the comet, and press it onto the device. Then apply more glue which laps up onto the side of the comet, and helps hold it in place during lift.
A more traditional way of installing rising tails on paper ball shells is to wrap the comet with a couple of turns of thin pasted kraft paper or moistened gummed tape. Have half of the strip lap onto the side of the comet, and half hanging off the bottom of it. Slice the overhang paper with scissors about every half inch and fold out the tabs. Apply Elmer's or wood glue to the bottom of the comet and to the tabs, and press in place on the top of the shell.
I like to cover the shell's rising tail with a disc of tissue paper, tied on with a bit of string. This dresses the shell up, and keeps the comet's prime layer from rubbing against anything during transport. These comet tails will ignite when the shell's lift gasses flow around them before the shell leaves the mortar.
Attaching Comet to a Aerial Shell for Rising Tail Effect
Test Firing the Two Different Gold Glitter CometsTo test fire the 3/4-inch and 1-inch comets made with the two different formulae, I shot them out of a star gun which has 7/8-inch and 1-1/8-inch tubes. I also tested some of the 1-inch comets out of a small paper mortar made with base #PL3002 and tube #TU2123.
Mortar and Star Gun Used to Test-Fire Glitter Comets
Using commercial FFFg black powder, I had to use a flat 1/4 teaspoonful for the 3/4-inch comets, and a flat 1/2 teaspoonful for the one inchers.
With my homemade red-gum granulated BP, I had to use a heaping 1/4 teaspoonful, and a heaping 1/2 teaspoonful respectively.
I installed 3-inches of visco fuse, the BP lift powder, and then dropped the comets in. If I was making these babies for a display, and they were going to be boxed and transported, I'd use a layer of tissue paper between the comet and the BP, and a layer of tissue pressed in above the comet to hold everything in place until firing.
Test ResultsBoth of the formulae resulted in beautiful comets, and the one-inchers would make a very nice addition to any display. I have to say I like the Gold Twinkler a bit better than the D1. The GT creates very golden, long hanging, large glitter, whereas the D1's glitter is a bit more pale, and does not hang quite as long.
But either one is very beautiful, and the economics of the D1 formula make it quite attractive to produce.
In order to have a rising tail on a shell that lasts as long as the shell's ascent before burst, I measured the burn times of various lengths of comets with the star gun and a stopwatch. I wrapped the comets with aluminum foil duct tape to simulate the amount of the comet surface that would be exposed and burning if it was attached to a shell.
Foil-Tape-Wrapped Comet Ready to be Fired and Timed
The burn times were as follows, along with the size of the shell to use them on:
|1/2-inch long||2.5 to 3 seconds||3-inch to 6-inch shells|
|5/8-inch long||4.3 seconds||8-inch to 10-inch shells|
|3/4-inch long||4.5 seconds||8-inch to 10-inch shells|
|1-inch long||5 seconds.||10-inch shells|
For tails on 12-inch shells, I'd use 1.25-inch to 1.5-inch long comets.
Shell rising comet tails can vary from 3/4-inch to 2.5-inch in diameter or larger, depending on the size of the shell.
ConclusionThe one thing I'd add about these beautiful gold glitter comets is that my wife, Molly, who is not passionate about fireworks--especially really loud ones--has always loved gold glitter effects. That's reason enough for me to use a lot of gold glitter in my fireworking.
Bonus RoundIt is easy to make a brilliant Silver Titanium Spark comet using the methods described above.
|Black powder meal||0.68||5 ounces|
|Spherical titanium||0.27||2 ounces|
|Total batch weight:||7.4 ounces|
Fine Ti will give a short, bushy tail. Coarse Ti will produce a longer tail filled with larger sparks.
These titanium comets produce an effect which contrasts nicely with the glitter ones.