Bow Drill - Description

Description

This is an ancient method of starting fire without matches or a lighter. It uses friction to generate heat. The heat eventually produces an ember in the burnt sawdust. The ember is tiny, smaller than the head of a cigarette, and fragile. Once the ember is formed it is carefully placed into a "tinder bundle" (a bird's type nest of stringy, fluffy, and combustible material). Once the ember is in the tinder bundle it is then carefully nurtured and coaxed into flame. Once the tinder bundle bursts into flame, it is then placed into the fire lay.

The spindle, carved to reduce friction at one end and maximize it at the other, is held in a hole in the bottom of the bearing block, and at the other by the hearth (fireboard). The string of the bow is wrapped once around it, so that it is taut enough not to slip during operation. A variation on this called the "Egyptian Bow Drill" which attaches the string by wrapping it around multiple times, or actually tying it to the drill or through a hole through the drill shaft, then wrapping it.

The usual position that a person assumes whilst operating the bow drill is as follows: the right knee is placed on the ground (assuming a right-handed operator) and the arch of the left foot is on the board, pinning it in place. The left wrist, holding the handhold, is hooked around the left shin and locked in place to keep it steady so it can generate enough downward pressure and speed; achieved by pushing down with the handhold and spinning the drill. The heat of the friction between the hearth and the spindle both creates charred, fuzzy dust and causes it to ignite - forming a coal or ember. The handhold is lubricated and the spindle is carved to about thumb thickness, usually 6 to 8 inches (150 to 200 mm) long. Another option to practice is to make the "handhold" into a "mouth-hold" piece, so it's held down by pressure from the chin/mouth, leaving both hands free.

An indentation and a "v" notch into the center of the dent is made into the fireboard and the spindle is placed on it. The notch allows a place for the dust collect while it is being abraded off the spindle and the hearth. Eventually, the friction generates heat to ignite the dust, which can be used to light tinder.

A Bow drill is used to get an ember (left), the ember makes tinder smoke (center), until a fire is lit (right).

Whilst a "v" is most common, other methods to create a cavity to contain the dust whilst it is being ignited can be used. For example, drilling part-way into a hearth made by lashing two sticks together from one side, and then drilling from the other side to meet this hole; or using the area where two branches separate. This is to keep the coal off wet or snow covered ground.

The hearth and spindle can both be constructed from any medium-soft, dry, non-resinous wood, and work best when both are made from the same piece of wood; however, with practice almost any wood combination can be used provided the parts contain little or no resin or moisture. The most important factor is whether the wood is dry enough to ignite, as wet wood will not work; yucca, aspen, white cedar, basswood, buckeye and most willows all work very well. Combinations such as hazel and poplar also work well. The bow should be stiff but slightly limber and around the distance from the users armpit to their fingertips. The bearing block (handhold) can be made of anything that is harder than the spindle. Bone, antler, shell and stone work best, as they can be easily greased, do not create as much friction, and do not burn; however, hard woods such as maple and tulip and red cedar are quite serviceable and often easier to find and work. Some effective materials used to grease the bearing block include sebum, animal and plant oils, or even moist vegetation.