15 Foot Crackling Dragon Eggs Mine

For reasons beyond my comprehension, people are forever calling up here and asking about making their own Chinese cakes. (A "cake" is a multi-tube repeating shot firework that shoots stuff up into the air.) I patiently explain to them that 1) they can buy these things reasonably at just about any fireworks stand, and 2) unless they ARE Chinese, that any cake they make will be distinctly NOT-Chinese. But they persist nonetheless. So here's a little project, sent in by Griffin Behm that can appeal to folks who want the satisfaction of making a repeating shot "cake." This is a perfect starter project anyone who has never made a firework device before.

This effect is sort of like a mine-finale chain. As the effect really only goes about 15 feet high, it might not be suitable for a professional display, but for that backyard fireworks show you do every year, it can go a long way.

Obtaining Materials

Black Powder. If you have access to real black powder, then use it. If not, get one of Skylighter's black powder making kits.

Crackling Balls. These are small Class C firework items sold around the Fourth. They are small green balls that are filled with a crackling star composition (called dragon eggs). They are sold in packs of six, so just buy two. If you don't have a year-round fireworks store near you, consider ordering on-line if possible. The great thing is they come with a length of visco fuse attached, meaning it's not necessary to buy extra visco fuse for this project. If you are so inclined, you can make your own dragon eggs using one of the several dragon egg formulas floating around.

Visco fuse. You'll be linking all these shots together, so you will need at least 10 pieces of visco. You could use one long piece (most reliable) or you can just be economical and use the fuses from the Crackling balls.

Procedure

First start by drilling fuse holes in all the tubes. To keep things simple, you might as well just drill an ‘in' and an ‘out' hole for each tube about 3/8 to 1/2 inch above the bottom of each tube. (The last tube doesn't need an ‘out' hole, don't drill it.)

Next assemble all the tubes on the 2 x 4. You'll want to make sure all the fuse holes are aligned, as we will be pushing fuse through them in a straight line. Glue (white/Elmer's glue's best; hot melt will work) all the mine tubes to the board with glue on the base of the mine tube as well as around each one. You should leave about 1/4 inch to 1/2 inch between mine tubes. Do this for each of the remaining mine tubes. When finished you should have a nice arsenal of mine tubes lined up ready to be filled with crackling stars.

Now take your visco fuse, and insert it into the fuse holes in a daisy chain fashion. If you have one long length just push it in the first ‘in' hole on the first mine tube and then right through the other mine tubes until you reach the back of #10. If you're using short individual lengths, make sure that some of the powder core is exposed on all visco fuse ends. Attach the visco fuse by pushing it into the ‘out' hole of a mine tube and then pushing it into the ‘in' hole of the next mine tube and so on and so forth.

The next step is to fill the mine tubes with a lift charge. This is where the black powder comes in. You will probably have to experiment with the amounts, but if you were to use Estes fuel you're going to want to fill the mine tube 3/8 of the way full with ‘rocket comp.' It's a good idea to measure the amount you're putting in as opposed to just randomly filling it. That way all the shots will be of equal height.

At this point add the effect, or the crackling stars from the crackling balls (dragon eggs). These will look like small round pellets (firework stars). You can just go ahead and dump all the crackling stars from each Crackling Ball into each min tube (one Crackling Ball per mine tube). Now the mine tube should be pretty much completely full with black powder and crackling stars.

As a final touch, cover all the openings of the mine tubes individually with foil in order to prevent premature ignition.

Firing

Place this impressive looking device out in the open somewhere. Fire/light the visco fuse and step back. You will hear a Whoosh and then a loud crackle of sparks. Just as the sparks are fading, another Whoosh and more loud crackling stars will be heard, and another, and another, and another, and another, and another, and another, and another, and then a final one. My! That was exciting, wasn't it!

Materials Needed
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