Set up a workspace well away from the house, work shed, and other structures on your property. Don’t work on firecrackers near trees, telephone poles, and other outdoor features. It’s best to set up on a concrete patio or bare dirt. Avoid working with explosives near dry grass or other plants that could catch fire. Wear goggles to protect your eyes while working with firecracker materials. [2] X Trustworthy Source Johns Hopkins Medicine Official resource database of the world-leading Johns Hopkins Hospital Go to source

One ping pong ball for each firecracker you plan to make. [3] X Research source Thick string, which will be used as the fuse. [4] X Research source A sharp nail and a razor to make holes in the ping pong ball. Duct tape or another sturdy tape to patch up the hole. Black powder, also known as gunpowder, which is available where ammunition is sold. It comes in small canisters. Before buying black powder, get familiar with measures you must take to handle and store black powder safely. [5] X Research source Nail polish, which causes the firecracker to make a louder noise.

Use a razor with a handle for greater precision. Be careful not to cut yourself as you wield it; the surface of the ping pong ball may be slippery. If you don’t have a razor, use a nail or another item to bore a few holes close together to create a hole large enough to pour the powder through.

If you have trouble threading the string through the hole, dip it in a bit of melted wax to create a hardened tip, then push the tip through the hole. For a slower-burning fuse, dip the length of the string in candle wax or beeswax. When you light the fuse, it will burn more slowly before the firecracker explodes.

Never smoke or light a flame while handling black powder. Take care not to spill any black powder in your workspace. If you spill some, clean it up with a dustpan and broom and dispose of it safely. As soon as you’re finished with the gunpowder, close the canister tightly and store it in a cool, dry place away from flammable or combustible substances.

DO NOT light the fuse until children, pets, and other people are at a safe distance from the firecracker. Never place a firecracker inside a glass bottle or drinking glass. The glass may break, and the aftereffects could be very dangerous. [11] X Research source