The forge is the heart of the blacksmith’s shop. It is in the forge that the blacksmith heats metal until it reaches a temperature and becomes malleable enough for him to use his other equipment to shape it.
The traditional blacksmith’s forge has evolved and become more sophisticated over time, but the basic principles remain unchanged. The most common forge is the one fired by coal, charcoal or coke. The forge is a specially designed fire place where the temperature can be controlled so that the metal is heated to the temperature the blacksmith wants, depending on what he plans to do - shaping, annealing or drawing. The there main parts of the forge are:
· The hearth where the burning coke (or other fuel) is contained and over which the metal is placed and heated.
· The Tuyere which is a pipe leading into the hearth through which air is forced. The strength of the fire and the heat it produces will depend on the amount of air being fed to it through the Tuyere tube.
· The bellows are the mechanism by which air is forced through the Tuyere tube into the hearth. While earlier bellows were pumps operated by muscles power, modern forges have high power fans or bowers to force air into the Tuyere
The blacksmith adjusts the mixture of air and fuel in the hearth the produce the exact temperature needed to heat the metal. A traditional blacksmith’s forge will have a flat bottomed hearth with the Tuyere entering it from below. The core of the fire will be a mass of burning coke in the center of the hearth. Around this burning coke will be a wall of hot, but not burning coal. This wall of coal serves two purposes. It provided insulation and contains and focuses the heat of the fire to a limited area, allowing the blacksmith to heat the metal in a precise manner. The hot coal also becomes transformed in coke which can then be used as fuel for the hearth.
The outer wall of the fire is made up of a layer of raw coal, which is often kept damp so as to control the heat of the inner layer of hot coal so that is may slowly “cook” into coke.
The size of the fire and the heat it produces can be changed by either adding or removing fuel from it as well and adjusting the air flow. By changing the shape of the outer layers of coal, the shape of the fire can also be modified to suit the shape of the metal piece being heated.
Many modern blacksmiths use gas forges. These are fueled by either natural gas or propane. The gas is fed into the hearth, which is lined by ceramic refractory materials, and mixed with air and ignited. The pressure at which the gas is being fed into the hearth can be adjusted to vary the temperature. While gas forges are easier to use and require less maintenance and cleaning, the drawback is that, unlike a coal fired forge, the shape of the fire is fixed and cannot be changed to suit the shape and size of the metal being heated.
