Ignition device
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An ignition device is a device that ignites fire. Many ignition devices obtain their energy from human muscle power, but others use sunlight, chemical energy, or electricity.
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[edit] Friction
There are numerous methods, building up the heat created by friction until glowing embers or even flames are produced:
- Fire Drill (Hand Drill, Fire Thong, Bow Drill, Pump Drill, etc.)
- Fire Plough
- Fire Saw
In these methods, two different varieties of wood are vigorously rubbed together, creating heat and finely powdered dust or 'char' composed of very hot partially combusted wood fibres. Char has a large surface area and a low ignition temperature of around 430C (800F) [1] and with the right technique will ignite and form a small glowing ember or 'coal'. This must then be gently introduced into a ball of very fine, dry tinder and blown on to produce a flame.
It is essential to use suitable woods for the rubbing parts: both parts must be dry, and one part must be of a harder wood, or use long grain against endgrain to produce the right dust. Essentially what happens is that one part disintegrates to form the dust while the other part becomes highly polished and hot enough to ignite the dust.
Often the process is performed in two stages: starting by rubbing slowly and pressing hard to produce a dark brown or black dust then switching to a lighter, faster stroke that creates the high temperature on the surface required for ignition.
Typically it takes a couple of minutes to produce fire by friction, although the record for the bow drill is 7.2 seconds[2]
[edit] Percussion
Stone and stone, or metal and stone are struck together to produce hot sparks. This is possible with many types of stone, but having to find them by trial and error in a survival situation is undesirable. Flint is easy to identify and is great for producing sparks, but clearly only of value where it is abundant
- Pyrite (and other Iron Sulphides)
- Fire-steel, strike-a-light
- Modern Ferrocerium 'flint and steel'
- Any Carbon Steel (such as a knife)
[edit] Compression
Here, heat generated by compressing air is used to create an ember. Due to the difficulties of making a fire piston, this technique is also likely to be impractical in most survival situations.
[edit] Sunlight
One of the easiest methods of creating fire is to use a lens or condensing reflector (such as a torch/flashlight reflector) to focus the energy from the sun onto tinder. It is most effective on dark coloured tinder which absorbs heat and light energy better (light coloured tinder reflects heat and light energy).
[edit] Electric
Electricity can be used to create fire either by using sparks to light tinder, or using the heat generated from electrical resistance. An ordinary lithium battery can produce enough heat to start a fire if a wire, piece of aluminum, or other suitable metal is used to short-circuit it.
[edit] Chemical
There are thousands of combinations of chemicals which will ignite when mixed together (some explosively). Probably the best-known for survival situations is potassium permanganate and glycerine or sugar. Chemical methods are likely to produce poisonous or toxic waste which should be contained until safe disposal is possible.
