Flint and steel, lighting our world!

As mentioned in another entry into this blog, no overnight trip into the forest is complete without a roaring fire for weary campers to gather around. But what if you wish to avoid using the trappings of modern society by not using something such as a lighter to start the flames?! This entry into the Woodland Science Guide will provide you with the knowledge and understanding to start a fire using two simple items- flint and steel.

 
Using a piece of flint and steel to start a fire is not a new method by any means; for thousands of years, mankind has employed these two resources to start this precious source of heat light. Striking a piece of high carbon steel against a sharp edge of flint in the correct way will cause sparks to fly away from the steel, igniting the kindling of the fire. Although practice is required to perfect the technique of creating sparks this way, it proves as an invaluable method of starting a fire. Despite this, not many understand the curious nature of the science behind this process, something this blog seeks to remedy.

To truly unravel the reason why this technique produces sparks hot enough to start a fire, one must examine the nature of steel and more specifically,the iron within it. Known as an alloy, steel is a mixture of various metals and can be crafted into different strengths depending on its composition. To be an effective 'firesteel' the piece needs to be approximately 98% iron and 2% carbon. Although hard, this steel is relatively brittle and will provide the necessary level of resistance for iron particles to be struck of by the flint.



But what exactly causes the tiny fragments of steel to become hot enough to start a fire? Simply put, the steel rusts. As confusing answer as this is, it is perfectly true in that steel with a high amount of iron will rust when exposed to oxygen in the air. The iron within the steel oxidises immediately upon contact with the air, causing a thin layer of iron oxide to surround the unoxidised iron and preventing it from rusting further. This process, known as oxidisation, is a reaction that causes both the iron to rust and give off heat simultaneously.

As the thin layer of iron oxide is preventing the piece of steel from simply igniting fully, the heat given off is very limited and absorbed by the surrounding area, this is where the flint is needed.
When the steel is hit with the flint at an acute angel, small shards of the brittle steel will break away. Pieces of this steel would have been completely unoxidised prior to the flint striking it. As the smaller shard of steel has a larger surface area in relation to its size, it rust extremely quicker exuding a much more intense heat. Although the heat will taper off quickly, it is usually a higher enough temperature to provide a spark and get the average kindling ablaze.


Firesteels are used frequently today by seasoned outdoors men and women, their availability, reliability and low price making them an attractive tool when tackling the great outdoors. This method not only allows both children and adults alike the chance to understand and witness an aspect of science that is usually ignored, it also a worthwhile skill that can be a benefit to anyone.