Fire Piston - Description and Use

Description and Use

A fire piston consists of a hollow cylinder ranging in length from about 7.5 cm to 15 cm (3 to 6 inches), having a bore 6–7 mm (about 0.25 inch) in diameter, sealed at one end and open at the other. A piston with an airtight circular seal is fitted into the cylinder. The piston has a handle on the end to allow a firm grip to be applied to it, or a large enough surface area to strike it sharply without causing pain while the cylinder is braced against a hard surface, and it can be completely withdrawn from the cylinder. The piston generally has a notch or recess on or in its face, into which a piece of tinder is placed.

The compression of the air when the piston is quickly rammed into the cylinder causes the interior temperature to rise sharply to 260°C (500°F). This is hot enough for the tinder on or in the piston face to ignite with a visible flash that can be seen if the cylinder is made of translucent or transparent material. The piston is then quickly withdrawn, before the now-burning tinder depletes the available oxygen inside the cylinder. The smouldering tinder can then be removed from the face of the piston and transferred to a larger nest of fine kindling material, such as hemp rope fibres, birch shavings, etc. The ember is then fanned or blown upon vigorously to create a flame, at which time various stages of larger kindling can be added until built into a proper fire.

Ancient and modern versions of fire pistons have been made from wood, animal horns, antlers, bamboo, or lead. Other metals have also been used in modern versions.