7.4 FIREWORKS

• FIRECRACKERS
• SKYROCKETS
• ROMAN CANDLES

7.41 FIRECRACKERS

1. Cut a small piece of cardboard tubing from the tube you are using. "Small" means anything less than 4 times the diameter of the tube.
2. Set the section of tubing down on a piece of wax paper, and fill it with epoxy and the drying agent to a height of 3/4 the diameter of the tubing. Allow the epoxy to dry to maximum hardness, as specified on the package.
3. When it is dry, put a small hole in the middle of the tube, and insert a desired length of fuse.
4. Fill the tube with any type of flame-sensitive explosive. Flash powder, pyrodex, black powder, potassium picrate, lead azide, nitrocellulose, or any of the fast burning fuel-oxodizer mixtures will do nicely. Fill the tube almost to the top.
5. Pack the explosive tightly in the tube with a wad of tissue paper and a pencil or other suitable ramrod. Be sure to leave enough space for more epoxy.
6. Fill the remainder of the tube with the epoxy and hardener, and allow it to dry.
7. For those who wish to make spectacular firecrackers, always use flash powder, mixed with a small amount of other material for colors. By crushing the material on a sparkler, and adding it to the flash powder, the explosion will be the same color as the sparkler. By adding small chunks of sparkler material, the device will throw out colored burning sparks, of the same color as the sparkler. By adding powdered iron, orange sparks will be produced. White sparks can be produced from magnesium shavings, or from small, LIGHTLY crumpled balls of aluminum foil.

   Example: Suppose I wish to make a firecracker that will explode with a red flash, and throw out white sparks. First, I would take a road flare, and finely powder the material inside it. Or, I could take a red sparkler, and finely powder it. Then, I would mix a small amount of this material with the flash powder. (NOTE: FLASH POWDER MAY REACT WITH SOME MATERIALS THAT IT IS MIXED WITH, AND EXPLODE SPONTANEOUSLY!) I would mix it in a ratio of 9 parts flash powder to 1 part of flare or sparkler material, and add about 15 small balls of aluminum foil I would store the material in a plastic bag overnight outside of the house, to make sure that the stuff doesn't react. Then, in the morning, I would test a small amount of it, and if it was satisfactory, I would put it in the firecracker.

8. If this type of firecracker is mounted on a rocket engine, professional to semi-professional displays can be produced.

1. Buy an Estes Model Rocket Engine of the desired size, remembering that the power doubles with each letter. (See sect. 6.1 for details)
2. Either buy a section of body tube for model rockets that exactly fits the engine, or make a tube from several thicknesses of paper and glue.
3. Scrape out the clay backing on the back of the engine, so that the powder is exposed. Glue the tube to the engine, so that the tube covers at least half the engine. Pour a small charge of flash powder in the tube, about 1/2 an inch.
4. By adding materials as detailed in the section on firecrackers, various types of effects can be produced.
5. By putting Jumping Jacks or bottle rockets without the stick in the tube, spectacular displays with moving fireballs or M.R.V.'s can be produced.
6. Finally, by mounting many home made firecrackers on the tube with the fuses in the tube, multiple colored bursts can be made.

1. Buy a 1/2 inch thick model rocket body tube, and reinforce it with several layers of paper and/or masking tape. This must be done to prevent the tube from exploding. Cut the tube into about 10 inch lengths.
2. Put the tube on a sheet of wax paper, and seal one end with epoxy and the drying agent. About 1/2 of an inch is sufficient.
3. Put a hole in the tube just above the bottom layer of epoxy, and insert a desired length of water proof fuse. Make sure that the fuse fits tightly.
4. Pour about 1 inch of pyrodex or gunpowder down the open end of the tube.
5. Make a ball by powdering about two 6 inch sparklers of the desired color. Mix this powder with a small amount of flash powder and a small amount of pyrodex, to have a final ratio (by volume) of 60% sparkler material / 20% flash powder / 20% pyrodex. After mixing the powders well, add water, one drop at a time, and mixing continuously, until a damp paste is formed. This paste should be moldable by hand, and should retain its shape when left alone. Make a ball out of the paste that just fits into the tube. Allow the ball to dry.
6. When it is dry, drop the ball down the tube. It should slide down fairly easily. Put a small wad of tissue paper in the tube, and pack it gently against the ball with a pencil.
7. When ready to use, put the candle in a hole in the ground, pointed in a safe direction, light the fuse, and run. If the device works, a colored fireball should shoot out of the tube to a height of about 30 feet. This height can be increased by adding a slightly larger powder charge in step 4, or by using a slightly longer tube.
8. If the ball does not ignite, add slightly more pyrodex in step 5.
9. The balls made for roman candles also function very well in rockets, producing an effect of falling colored fireballs.

<--Tear gas-->Index<--Suppliers and info-->