The classic smoke bomb is a great project for the home or lab, producing lots of safe smoke, with purple flames. If you get dye and consider the shape of your creation, you can make a smoke bomb that billows clouds of brightly-colored smoke. This project is easy and safe enough to do at home. Adult supervision is required.
Ingredients
- 60 g (3 tablespoons) potassium nitrate (sold as saltpeter in garden supply shops)
- 40 g (2 tablespoons) sugar
- 1 teaspoon baking soda
- 60 g (3 tablespoons) powdered organic dye (found in laundry sections of the store as well as craft & hobby shops)
- cardboard tube ( an iced push-pop tube works (eat the treat first), or you could use a toilet paper roll or section of paper towel tube.
- duct tape
- pen or pencil
- firework fuse from hardware, rocketry, construction, or hobby shops, or scavenge it from a firework (just make sure it is not broken or it will dud)
- cotton balls
- saucepan
Step 1
Mix 60g potassium nitrate with 40g sugar in a saucepan over low heat. It's a 3:2 ratio, so if you don't have a method of measuring grams, use three tablespoons of potassium nitrate and two tablespoons of sugar.
Step 2
The sugar will carmelize and brown. Stir the mixture continuously until it resembles smooth peanut butter.
Step 3
Remove the mixture from heat.
Step 4
Stir in a spoonful of baking soda (rounded teaspoon is fine). The baking soda is added to slow down the combustion when the smoke bomb is ignited.
Step 5
Add three large spoonfuls (3 tablespoons) of powdered organic dye. Blue dye and orange dye are said to produce better results than the other colors. Stir to mix well.
Step 6
Construct the smoke bomb while the mixture is still hot and pliable.
Step 7
Fill a cardboard tube with the warm smoke bomb mixture.
Step 8
Push a pen or pencil down into the center of the mix (doesn't have to be all the way to the bottom but should be enough that the pen stands in the mixture). You could use a different shape, but the cylinder works really well.
Step 9
Let the mixture harden (about an hour).
Step 10
Remove the pen.
Step 11
Insert a firework fuse. Push pieces of cotton balls into the hole to tamp the fuse securely inside the smoke bomb. Be sure there is fuse left outside of the tube so that you will be able to light your smoke bomb.
Step 12
Wrap the smoke bomb with duct tape. Cover the top and bottom of the tube, too, but leave the hole area with the cotton and fuse uncovered.
Step 13
Go outside and light your smoke bomb!
Tips
- Throw it as far away from you as possible
- Know your local laws concerning these matters to avoid prosecution.
Warnings
- Be at least 10 meters away from the smoke bomb after ignition to appreciate it's full glory (and also to prevent accidents).
- Anything involving strong oxidizers or the use of fireworks can be dangerous. Exercise extreme caution.
Things You'll Need
- A large, open area, away from flammable substances, structures, and wildlife.
