The Stolen Secret to Making Glittering Microstar Mines
A "mine" is a fireworks device which fires burning stars or other fireworks, like small shells or spinners, etc. up into the air from a mortar (typically on the ground, but sometimes, in stage effects, they are mounted on frames or poles).
Microstars are just tiny little fireworks stars. They're ridiculously easy and fast to make.
One thing makes this a great project: you don't need to make black powder to fire the microstars up. This saves you money, time, and hassle.
All you need is quick and easy-to-make microstars, some tubes, Visco fuse, a couple of screens and a few things you can probably find around the house.
My friend, Tom Dewille, invited me to come visit his factory in Alabama for a few days. He owned and ran one of the leading companies in the world that made stage and theatrical pyrotechnic devices, like these microstar mines. This is stuff you see onstage in rock concerts.
First, Tom made up a fresh batch of microstars, which were dry within a couple of hours.
Then around 10 or 11pm, night owl Tom started assembling the microstar mines.
"Now the secret," he said. "This is how I make stage mines which don't have any lift powder in them at all."
I was all eyes, because I had no idea how that could be done.
I had made plenty of 3-inch bag mines: just black powder lift charge in a bag and some stars on top of that. Ignite the lift charge and up into the air go the burning stars.
But I had no idea what is gonna make those stars fly out of the mortar all by themselves.
And the funny thing was, even while I watched how he made his little microstar mines, I still didn't see how they would work. So the thick just plottened...
Then we went outside and fired a couple. Of course, they worked perfectly as he promised. They fired a beautiful spray of twinkling glitter stars up into the air. With no lift powder, just like he said they would.
Here's how he did it.
Making the Microstars
Here's a really simple way to make microstars that you can use in mines, fountains, rocket tails, and many other fireworks. You can do this with virtually any star color or effect, but D1 Glitter is what we're using in this project.
First, mix yourself up a batch of D1 glitter star composition. There's a D1 Kit and a detailed tutorial for making it on the Skylighter Star Kits page. After mixing the dry chemicals, set about 1/4 of the dry mix aside.
Using a spray bottle, add just a little water to the mix. Then begin kneading the water into the mix, continuing to add a little water at a time until it's just right.
Here's what "just right" means.
Grab a handful and squeeze it. It's perfect when it holds its shape without breaking up AND no water squeezes out between your fingers.
It's easy to over wet this mix. If it's too wet, you can fix it by kneading a little of the dry D1 comp back into your mix to take up the excess water. Then test again, dampen if necessary, until you get it right.
Once the "potato" of comp is properly damp, "rice it" through a 10-mesh screen to granulate it into micro-stars (more information on sizing your micro-stars below). Spread the damp stars out on a paper lined tray to dry. After the stars dry, break up any clumps. Then screen the fines out.
The Secret of the MicroStar Mine
Once your stars are dry and properly sized, here's the how to construct your mine.
"You don't need lift powder to shoot the stars up" said Tom. Instead, you can harness the back pressure of the stars burning in the tube to make them go up.
"All you have to do is insert a tight fitting plug and tape over the mouth of the gun. You'll be surprised how well it works."
Tom had figured out how to use 8-mesh micro stars to propel themselves out of the 3/4-inch inside diameter tube.
Here're the exact steps you need to take.
First, attach your mine tube to a stable wooden base. (Here is the wrong and the right way.)
After your tube is firmly attached to a base, poke or drill a 1/8" or 3/32" diameter fuse hole in the tube as low as possible, just above the base. Then insert a 3" long piece of Visco all the way into the hole.
Now here comes Tom Dewille's ninja pyro secret. (You can win bets with this, because even experienced fireworks makers have never heard of it or seen it done.)
First load the microstars into the mortar (see below for star size and quantity).
Next, shove a tight fitting plug all the way down to the bottom of the tube, right on-top of the stars. The purpose of the plug is to keep the stars in place and to create some back pressure when the stars ignite. If you don't have a plug, you can cut one out of something the thickness of a manila folder.
With me so far?
Now here is the final trick that makes this work. And you might never guess that it makes any difference. But it really does! (If you don't believe it, make a mine with and without this last step.)
Cut a piece of masking tape wide and long enough to completely cover the mouth of the mortar and come down the tube about 1/4 inch. This part is absolutely critical to containing the pressure long enough to fire the stars up and out of the mortar.
Now you're done. Set your mine up in a safe place, and light it.
Tom's Tips and Tricks:
If you want the mine stars to go higher: Tom suggests using one piece of masking tape first, and trying 2 pieces at right angles next. Also, you might try bringing the tape further down sides of the mortar tube than 1/4″.
The size of the dry microstars.
- For mortar tubes smaller then 1/2-inch ID, 10 mesh stars work well. (Or you can use stars which pass through a 10 mesh screen but are retained on a 12-14 mesh kitchen colander or window screen.)
- For tubes between 1/2-inch and 1-inch ID, 8 mesh stars work well. If you don't have an 8-mesh screen, just use dry micro stars which pass through a 4 mesh screen but are retained on a 10 mesh screen.
- For tubes up to 1-1/4-inches, use 4 mesh stars
You can use any star formula. You are not limited to D1 Glitter.
This technique will probably not work on tubes with inside diameters larger than 1-1/2 inches. At that size and above, use black powder lift charges.
Break up clumps of micro-stars before screening to your desired size. Then be sure to screen out all fines after drying your micro-stars. The crumbs and fines burn faster and make the shots inconsistent.
For slower burning stars, such as organically fueled color stars, prime them with hot black powder. The BP prime will help light your stars, and provide extra "lift" for them. And since the slower formulas burn longer, you will probably need to use smaller micro-stars. You don't want hundreds of stars burning on the ground.
But... since neither you nor I are as practiced as Tom Dewille, some stars will probably remain in the tube burning. And a few will fall to the ground around the mortar. So, make sure you place your mortar in a place where burning stars won't ignite something nearby, such as other fireworks.
- Harry Gilliam