There are many ways to start a fire. For instance, campers usually bring along a lighter or match, army men might bring their fire starter if you’re doing it old school, you can use wood or bones to start a friction-based fire, and you can also use a lens and sunlight to start a fire. In this short demonstration, we bring you a cool experiment on how to start a fire using a 9-volt battery and steel wool.
All you need is a battery (which in this demo, we prefer to use a 9 volt one because it has both terminals at the same end) and fine steel wool. Simply stretch out the steel wool so that it touches both ends of the battery terminals. Almost instantly, the steel wool will puff up and ignite.
If you are going to set a bonfire, make sure you have your tinder pile at the ready, because this all happens very quickly!
How does it work?
The basic principle involved is steel wool is a good conductor and battery is the power source. The moment we make contact between the steel wool and battery, the “electrical current” flows through the steel wool and the fine steel wool gets hot enough to create sparks and burn. If we try this using thicker steel wool, which strands are of a larger diameter, then there isn't enough "resistance" in the strands. We might not get any spark but we may later feel the battery getting warmer. In fact, we are discharging the battery.
A nine volt (9V) battery is considered a high voltage supply for small diameter strands of steel wool. Thus, the higher the voltage, the more current will flow and the hotter the steel wool strands will get.
Try to get an assortment of steel wool, an assortment of batteries and play and observe for a while. You may need some testing to find what the optimal combinations are to get the instant spark. Don’t forget the safety aspects. Get an adult to help you and be careful with fine steel wool as it can get in your skin like a splinter. Finally remember not to keep the battery and the steel wool together in your pocket or pack or they could start a fire on their own!
Shared by Izhana
Learning Specialist, Petrosains