By Anne Marie Helmenstine, Ph.D.
Firecrackers are extremely easy and inexpensive to make yourself. You may want to make your own firecrackers because you are interested in learning how to make simple fireworks or it may be you are unable to obtain fireworks where you live.
Fortunately, the materials needed to make your own firecrackers are very common.
You will need: (homemade firecracker materials)
1.) tape (e.g., transparent tape)
2.) toy gun caps (either the tape or the rings) or black powder
3.) fuse (you can make your own fuse)
4.) pin or needle
Toy gun caps are nice because the powder used in them is easy to work with. Here's how to get the powder out of the caps:
Gently insert a pin or needle through the back of a cap through to the front. Remove the pin and re-insert it from the front, where you made the hole. Pry the powder out of the cap, tapping it onto a sheet or paper or plate or other working surface.
Carefully work the pin around the edge of the cap to collect all of the powder. There is a very slight chance of popping the cap, so be gentle and work slowly.
How much powder you need depends on the size of firecracker you plan to make. One ring of caps is more than sufficient to create a loud bang, but you really only need powder from about 3 caps for each firecracker. For the sake of safety, it's best to make one firecracker at a time (you don't need a big pile of powder).
Now let's assemble the firecracker.
One you have all of the materials necessary to make firecrackers, you are ready to start putting the firecrackers together.
1.) Take a piece of tape about 2" long and pick up the gunpowder on the sticky side of the tape. Evenly coat the tape until you either run out of gunpowder or else run out of stickiness.
2.) Place the fuse (about 2 inches long) so that it sticks halfway down the tape. The fuse does not need to stick to the tape.
3.) Roll the tape around the fuse. Take another piece of tape and tightly wrap your firecracker. Be sure to cover the bottom of the firecracker or else the opening will give you a small rocket rather than a popping firecracker.
Alternatively, you could just fold a 2-inch strip of paper in half lengthwise, pour the gunpowder into the fold of the paper, and wrap the paper around the fuse. The paper firecracker could be secured with any kind of tape.
Now that you have a homemade firecracker, you need to light it! This is basically the same as lighting any other firecracker.
Make sure you light it on a firesafe surface, far from people or pets.
Don't hold the firecracker in your hand when you light it.
Firecrackers that you buy contain measured quantities of gunpowder. You can estimate the amount of gunpowder in your firecracker based on how many caps you used.
You won't necessarily get a louder 'bang' using more gunpowder, but you will increase the potential risk of injury, so don't go crazy making big firecrackers. Have fun!