The forge is the main part of the blacksmithâs shop which heats metal until it reaches a temperature and becomes malleable enough to shape it using his equipment. In a very simple terms, the forge is just a special type of fire place with special design to help blacksmith heat up metal to particular temperature.
The most common forge is the one fired by coal, charcoal or coke.
The there main parts of the forge are:
Â·Â The hearth or firepot: The place where burning coke (or other fuel) is contained and over which the metal is heated.
Â·Â The Tuyere:Â 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 into it through the Tuyere tube.
Â·Â The bellows or blower : The mechanism by which air is forced through the Tuyere tube into the hearth.
Since the evolution of blacksmithâs forge, it has evolved and become more sophisticated, but still the basic principle remains the same.
While earlier bellows were pumps operated by muscles power, modern forges have high power fans or bowers to force air into the Tuyere.
TheÂ blacksmithÂ adjusts the mixture of air and fuel in the hearth producing the exact temperature needed to heat the metal.
A traditional blacksmithâs forge comes with a flat bottomed hearth and the Tuyere entering it from below. The core of the fire will be a mass of burning coke in the centre of the hearth. If you take a really close look at the coal which is around the burning coke is not on fire it is just hot.
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The wall of coal serves a dual purpose: it provides insulation and focuses the heat of the fire to a limited area, allowing the blacksmith to heat the metal in a precise manner.
Â The hot coal then turns itself into 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 âcookâ 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. What is really interesting is that if you change some of the layers of the coal by changing the shape of it, it actually modifies the shape of the fire.
ModernÂ blacksmithÂ uses gas forges. Depending on the local availability and the preference, blacksmithâs forge is fuelled by one of two gases: propane or natural gas. It has to be mixed with air to ignite it. You can adjust the temperature through the pressure at which the gas is being fed into the hearth.
Although ease of use and less maintenance and cleaning requirement being the advantage, the main drawback is that the shape of the fire is fixed and cannot be changed to suit the shape and size of the metal being heated.