There are hundreds of ways a person can build a flame thrower but I thought I would make a simple one using a biological organism instead of the typical fuels one might see. Lycopodium clavatum is a club moss that grows abundantly in the northern regions of Canada, Norway and Russia. The spores (seeds) of this moss are very tiny and are very high in fat content. Because of the fat content they are very flammable when aspirated (when air can get between the spores) which makes it the perfect fuel for making a simple, cheap flame thrower!
How to make a Flame Thrower from Moss Spores
-Remove the tube inside the wash bottle (you may need to cut it out with scissors). Cut the curved tip of the wash bottle to increase the size of the hole at the tip. Then fill the wash bottle with lycopodium powder.
-Turn the wash bottle upside down and squeeze away from your face/eyes to be sure powder can exit the bottle. Next, light the propane torch and spray the powder toward the lit end of the torch and away from yourself and other people. Move the wash bottle flame away from the propane.
(See the potential hazards at the bottom of this page before attempting to use this device!)
How does the Moss Spore Flame Thrower work?
A spore can be thought of as a seed that is dispersed so that a new plant will grow in a new area. A spore is different from a seed in that it is usually unicellular (only one cell) where as a seed is usually multicellular (many cells). But, the Lycopodium clavatum spore is high in fat content relative to its small size. Fat and oils (or lipids) are flammable. We can use these properties to do some amazing science tricks!
Recall that fire needs three things: Fuel, Heat and Oxygen. In the flamethrower, the fuel is the Lycopodium powder, the heat is supplied by the torch (and then by the combustion of the lycopodium as it burns) and the oxygen is supplied by the air. Lycopodium does not burn well when it is in a mound or pile because oxygen cannot get inside the small spaces between the spores. However, when the spores are aspirated (this means that they are allowed to spread out and air can get between the spores) oxygen is allowed to fill the space between each spore and it can quickly light. This is what allows the Lycopodium to explode into a fireball!
Hydrophobic Properties of the Lycopodium Moss Spores
Lycopodium is very hydrophobic. Hydrophobic literally means "water fearing". This is because of the high lipid (fat) content in the cell wall. Fats are not soluble in water which means they are hydrophobic.
This hydrophobicity is one of the best properties of Lycopodium because it allows lycopodium to float on water and to easily coat an object that is placed into the spore/water solution (see the video above). In fact, it is so hydrophobic that it can be poured out of the water, through a flame, and still burst into flames!
The Flame Thrower is Very Dangerous!
Hazards and Disclaimer:
I have included this tutorial so that science teachers and other professionals might learn from it and share this science with young people. I have not included this tutorial to encourage anyone to build a flame thrower. The dangers are VERY real and this flame is incredibly hot. Never use this device indoors or near bystanders. Using this flamethrower incorrectly could cause property damage, personal harm or harm to other people. We at Beals Science, in no way, endorse or encourage you to make a flame thrower from moss spores unless you are a science teacher/professional who is trained to deal with such hazards.