The fire piston, also known as a slam rod fire starter or fire syringe, is a gadget of the ancient origin used to start fires. Both modern and ancient fire piston versions were made from animal horns, wood, bamboo, lead or antlers. Fire Pistons are based on the principle of heating gas (air in this case) by adiabatic and rapid compression to light tinder, which is used for setting light to kindling.
What Exactly is a Fire Piston?
A fire piston is made of a hollow cylinder with length ranging from roughly 7.5 cm-15 cm. It also has a bore of around 7 mm in a diameter which is opened at one end and sealed at the other. The cylinder is fitted with a piston having an airtight round seal. It contains a handle on its end to allow for applying a firm grip. Generally, the piston has a recess or a notch in or on its face, where tinder is placed.
Swiftly ramming the piston into the cylinder causes the air to compress and make the temperature in the inner part of the gun to rapidly rise to 500 degrees fahrenheit. This temperature is high enough for the tinder in or on the face of the piston to light with a flash that is visible in a transparent or translucent cylinder. The piston is withdrawn quickly before the tinder, which is now burning, can deplete the oxygen in the cylinder. At this point, it is safe to remove smoldering tinder from the piston’s face and taken to a fine kindling material. To create a flame, the ember is blown or fanned upon vigorously. Various stages of the larger kindling are then added until such a time that a proper fire is built.
How to Use A Fire Piston
Both the O-ring and string gasket fire pistons usually work well although the string ones tend to be a tougher to use. Each time that you attempt to get a coal, lubricate the string using Vaseline as this helps better seal the cylinder to enable more air compression. Remember that the more the compression in the cylinder, the higher pressure, there will be. This will make it easier for the hot air to light the tinder on the end of the plunger.
Using char cloth as tinder appears to ignite more easily compared to the tinder fungus but both will generally work to produce a coal. However, you need to make sure that you do not drop the tinder in the cylinder because it is not likely to work. Dropping or leaving tinder into the cylinder may make the cylinder to have too much tinder, which would make the piston to “bottom out” inside the cylinder when it hits the excess air. This will most likely result in cracking the piston cup. Furthermore, it will be difficult getting the coal out of the cylinder.
Put the plunger far away from the cylinder. This implies pushing it down inside the cylinder so that the cylinder covers the gasket. This will result into the cylinder providing the longest stroke and at the same time trapping most air for compression. The more the air is compressed, the higher the pressure. This means that temperatures will need to be higher in the cylinder to successfully light the coal.
You’ll also need to hit the plunger in FAST, HARD and SQUARELY. Then, pull the plunger out IMMEDIATELY and blow on your tinder. I mean exactly HARD and FAST. The reason I say SQUARELY is because if you hit the plunger at an off-center position, sideward pressure will be put on the plunger, which can crack it.
At first, try using a char cloth in place of tinder fungus until you are experienced in using the fire piston. Additionally, in case you are using tinder fungus, you need to scrape a bit of the fungus’ top with your fingernail. This will make it easier for heat to light a coal.
In case you try at first and there is no IMMEDIATE formation of coal, try it again. It is possible that the tinder might have been heated to the temperature of ignition at the first time. Thus, another hit is most likely to ignite it. Note that the air needs to heat the tinder to more than 700 degrees to make the coal start glowing.
Humidity will also make it difficult to get the coal to ignite. Therefore, on damp days, you may need two to three hits to make the coal form.
- Prepare First: Before you use the fire piston, make sure that you have your tinder bundle at the ready. You must be able to transfer the ember immediately to more tinder.
- Lubrication: Occasionally lubricate or grease the string gasket using Vaseline. The seal is likely to weaken after a few tries, and the Vaseline helps in recreating the seal.
- In case your fire piston contains an O-ring gasket, there is no need to lubricate it.
- Use full strokes: Begin with the plunger at the farthest end of the compression chamber. The gasket needs to be started just into the chamber. The purpose is to allow a larger air volume to be compressed. This results in greater temperatures and improved ignition.
- Compress Fast: The plunger should be hit forcefully and quickly to enable it to compress all the air inside the chamber into an extremely small area and in a short time.
- Humidity makes ignition to be more difficult. This is because each attempt at compression will heat and dry the tinder, and several attempts may be required to spark an ember.
- Make use of good tinder like char cloth. This is even more important when you are learning how to use the fire piston.
The fire piston is an important device for outdoor survival. Learning how operate a fire piston will help you easily make a fire when you are either camping for fun or are stranded in the wilderness. And properly knowing how to operate this tool could literally mean the difference between life and death.