Building a blacksmith forges requires a heat source, body and stand, each of which take different forms depending on the forge design used. Common heat sources include blacksmith's coal and propane. For any design, line the interior of the body with a heat insulating material, such as furnace cement, firebrick or ceramic fiber blanketing.
For the forge body, use a thick walled metal container, such as an old air tank, bucket or sink. For gas heated forges, drill holes to connect the fuel lines and burners into the body before lining the body interior with the chosen insulating material. Weld any holes or cracks in the forge body shut, with the exception of the entry hole or door.
For coal powered forges, line the body with the insulating material, making sure to create a bed for the coals to burn on. For best results when using coal, install ventilation and air flow systems for safety and to provide the most efficient results. Consider a shop vacuum for an easy air flow generation system.
For either type of forge, build a sturdy base that elevates the forge and safely dissipates the heat. Complement the forge with a metal or ceramic water bath for quenching, as well as an anvil for hammering the metal.