It’s easy to make a homemade colored smoke bomb. Like the classic smoke bomb recipe, a colored smoke bomb produces purple flames and lots of smoke. But, including the right dye produces billowing colored smoke.
Colored Smoke Bomb Materials
The key ingredients for a colored smoke bomb are potassium nitrate, sugar, and an organic dye. Regular water-based dye will not work. Baking soda moderates the reaction so it doesn’t burn too quickly, while duct tape holds pressure in the tube to force out smoke.
- 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 (such as synthetic indigo or an aniline-based dye, found in some craft & hobby shops; colored oil pastel crayons)
- Cardboard tube (best is an iced push-pop tube (eat the treat first), or you could use a toilet paper roll or section of paper towel tube, or rolled paper tube)
- Duct tape
- Pen or pencil
- Firework fuse (find at hardware, rocketry, construction, or hobby shops)
- Cotton balls
Make the Colored Smoke Bomb Mixture
Note: While you’ll get the best results by cooking the potassium nitrate and sugar mixture, it isn’t strictly necessary. Another option is to mix potassium nitrate, sugar, baking soda, and organic dye with just enough water to hold the mixture together. Keep in mind, the mixture needs to dry before adding the fuse and taping up the smoke bomb, or else it won’t burn.
- Mix 60 g potassium nitrate with 40 g sugar in a saucepan over low heat. It’s a 3:2 ratio, so if you don’t have grams, use three large spoonfuls of potassium nitrate and two large spoonfuls of sugar (3 tablespoons potassium nitrate to 2 tablespoons sugar).
- As the sugar melts, the mixture carmelizes and turns brown. Stir the mixture continuously until it resembles smooth peanut butter.
- Remove the mixture from heat.
- Stir in a spoonful of baking soda (a rounded teaspoon is fine). Baking soda slows down the combustion when the smoke bomb is ignited, producing more smoke and helping it to last longer.
- Add three large spoonfuls (3 tablespoons) of powdered organic dye. Blue dye and orange dye tend to work better than other colors. Also, you can mix colors. Stir to mix well.
- Construct the smoke bomb while the mixture is still hot, as it becomes less pliable as it cools.
Assemble the Smoke Bomb
- Fill a cardboard tube with the warm smoke bomb mixture. Alternatively, fold a sheet of paper in half, place the mixture in line down the center, and roll the paper up to make a tube.
- Push a pen or pencil down into the center of the cylinder just far enough that the pen stands in the mixture. This makes a space for a fuse.
- Let the mixture cool and harden for about an hour.
- Remove the pen.
- Insert a firework fuse. Push pieces of cotton balls into the hole to tamp the fuse securely inside the smoke bomb. Make sure to have a long enough fuse outside of the tube to light your smoke bomb.
- 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.
- Go outside and light your colored smoke bomb!
Tips and Safety
- Only light smoke bombs outdoors in a well-ventilated area. Because smoke bombs produce heat, don’t use them near flammable materials or leave them unattended. You can extinguish a smoke bomb with water or a fire extinguisher, if necessary. Adult supervision is required.
- The key to getting vibrant colored smoke is using the proper dye. Google “colored smoke dye” to find reputable online sources of the dyes. Some people use colored wax crayons (oil pastels) as a readily available dye source. These will work, but the color they produce may not be as vivid as if you used the pure dyes. Also, melting pastel crayons may produce fumes. Don’t bother trying water-based dyes (like food coloring) because they simply won’t work. Colored smoke is vaporized dye. It isn’t a result of burning the pigment!
- Consider the physics and geometry of the smoke bomb to get the best effect. The reason you wrap the paper or cardboard tube with duct tape is so enough pressure builds up in the device to push out colored smoke, but not too much pressure builds up to split the smoke bomb open. At the same time, you want a smoke bomb to break if pressure gets too great (for safety).
- Baking soda in the mixture moderates the reaction so you get smoke rather than fire. But, it’s not an essential ingredient. You can make a smoke bomb using just the 3:2 ratio of potassium nitrate to sugar or a 5:3 ratio of potassium nitrate to sugar (e.g., 1-1/2 cups potassium nitrate and 1 cup sugar). Increasing the sugar helps the smoke bomb burn more slowly and produce smoke, but makes it harder to light. Increasing the potassium nitrate helps the smoke bomb burn better, but also more quickly and with less smoke. Feel free to experiment with the recipe.
Dyes and the Colors They Produce
Some companies list smoke bomb dyes according to color, while others list the chemical names. Here is a list of some dyes you can order online and the colors of smoke they produce:
- Disperse Red 9 (older formulation)
- Solvent Red 1 with Disperse Red 11
- Solvent Red 27 (C.I. 26125)
- Solvent Red 24
- Solvent Yellow 14 (C.I. 12055)
- Vat Yellow 4 with benzanthrone (older formulation)
- Solvent Yellow 33
- Solvent Yellow 16 (C.I. 12700)
- Solvent Yellow 56
- Oil Yellow R
- Vat Yellow 4 with benzanthrone and Solvent Green 3 (older formulation)
- Solvent Yellow 33 and Solvent Green 3
- Solvent Green 3
- Oil Green BG
- Solvent Blue 35 (C.I. 26125)
- Solvent Blue 36
- Solvent Blue 5
- Disperse Red 9 with 1,4-diamino-2,3-dihydroanthraquinone
- Solvent Violet 13
- Moldoveanu, S.C. (November 1998). Analytical Pyrolysis of Natural Organic Polymers. Elsevier. ISBN 9780444822031.
- Sparky. The Chemistry of Pyrotechnics.
- Turnbull, Stephen (2004). Ninja AD 1460 – 1650 (3rd ed.). Oxford: Osprey. ISBN 978-1-84176-525-9.
- Visser, Wouter (2003). Practical Pyrotechnics.