Set this pumpkin ablaze using lycopodium powder.
Using simple materials available at your local hardware and grocery store, you can make a spectacular flaming pumpkin with lycopodium. Lycopodium powder is a very fine yellow powder made from the spores of Lycopodium clavatum, also known as stag’s horn club moss and running ground pine. Lycopodium powder does not readily burn unless it is dispersed as a mist near flame, where it can ignite because of presence of oxygen to support combustion as well as the increase in available surface area.
This reaction simulates the same process that leads to grain elevator explosions and fires. Like lycopodium, grain dust is not particularly flammable on its own, but when some of the finer particles disperse into a mist and mix with oxygen, it makes for a highly flammable environment that easily ignites from even a small spark. Does this Spark an idea?
1. Hollow out and carve a Halloween pumpkin. Because fire will be the centerpiece of your lycopodium pumpkin, you may want your design to reference fire-breathing dragons, demons or similar characters. Make sure that your pumpkin has a solid lid at the top, and that your pumpkin has holes carved into the design so air can get in.
2. Cut a small hole in the back of the pumpkin and run Tygon tubing (or other heat-resistant tubing) through it. Leave about 3 feet of tubing outside the pumpkin.
3. Place a candle inside the pumpkin. Keep the candle settled and stable inside the carved floor of the pumpkin.
4. Using a funnel, pour a few grams of lycopodium powder in the tubing. Allow the powder to settle about halfway down the tubing, but don’t let it get all the way to the pumpkin.
5. Light the candle inside the pumpkin and replace the lid on top. Announce that you are about to set the pumpkin ablaze, and warn those nearby that the pumpkin may explode from the force and heat of the flames.
6. Direct the end of the tubing inside the pumpkin to point directly at the candle flame. Using a short, concentrated breath of air, blow through the tube so that the flame ignites the powder. Stand back and keep others well away—fire and flames will burst through the front of the pumpkin.