Fireworks Blog

Today, I will tell you about my process to make 2" inch spherical shells casings. I made a small former using molten lead from an old car battery. One piece is the "male" and other the "female". Having the former made, all you need is 2 pieces of 1mm thick cardboard cut into a cross-like shape with the external tips larger than the internal and 2 pieces of paper or newspaper, and, of coarse, some glue. Then, you must press the pieces between the "male" and "female" parts of the tool using an hydraulic press, remove the parts and just adjust the edges with some cutting tool. Below, is the paper shapes and required position before pressing: Here, is the homemade tool used to press the shapes in place: And finally, you can see the final result: Here is a shell made of casings like this: Look at how uniform is the paper after the shell explosion:

There are many types of consumer fireworks in Brazil. One of the smallest is a firecracker commonly named "Traque". This is what it looks like outside (it remembers a match!): And inside: As you can see, there's a little quantity of flash powder inside and the fuse is similar to a long match head ( a composition glued to a wood stick ). This fuse takes about 5 seconds to burn. Some people light them on hand and throw them, but I do not recommend that. The best way to light it is to put it in some place, light it and them walk away some meters. I think the quantity of flash powder is not the same on every bomb, because some do a loud bang and others just a "puff".