Firing ceramics in a fire, often through methods like pit firing, involves preparing a heat source, arranging the pottery, and protecting it during the process. Based on the provided reference, here is one method for firing ceramics using a fire in a pit:
You can fire ceramics in a fire by building a fire in a pit to create a bed of hot coals, carefully placing your pottery among stones on the coals, and covering the pieces to protect them from direct contact with falling embers.
A Method for Firing Ceramics in a Pit Fire
This technique, often considered a primitive or traditional method, utilizes a simple fire pit to achieve the temperatures needed to harden clay pottery. The core principle involves creating a controlled environment within the fire to ensure the pots are heated evenly and protected from damage.
Here's a breakdown of the process as described:
- Prepare the Heat Source: Begin by building a fire directly in the pit. The goal is not just flames, but to produce a substantial layer of coals at the bottom. These coals will provide the consistent, radiant heat necessary for firing.
- Set the Base: Once you have a good bed of coals, place stones on the coals. These stones serve multiple purposes – they provide a stable base for the pottery, help distribute heat, and lift the pots slightly above the most intense heat of the coals, preventing direct contact that could cause thermal shock.
- Stack the Pottery: Stack the pottery on the stones. Carefully arrange your ceramic pieces so they are stable and have adequate space for heat circulation. The reference notes that the tops of the pots should be just at ground level, suggesting a pit depth relative to the size of the pottery being fired.
- Protect the Pottery: To prevent damage from the main fire built on top, place cover sherds (broken pieces of pottery) over the pots. These sherds act as shields, keeping coals from the fire from falling down and contacting the pottery. Direct contact with large coals can cause uneven heating or pitting.
Practical Considerations
- Pit Depth: The pit depth is crucial, as the reference suggests the tops of the pots should be near ground level when stacked on stones over coals. This helps manage the layering of fuel and protection.
- Type of Wood: While not mentioned in the reference, the type of wood used for the fire impacts the heat and duration of the firing. Hardwoods generally produce longer-lasting coals.
- Firing Duration: The total time the pottery needs to remain in the heat will depend on the clay body used, the desired result, and the temperature achieved in the pit. This method typically achieves lower temperatures compared to modern kilns.
- Cooling: After the fire burns out and the coals cool, the pottery must cool down slowly to prevent cracking. Rapid cooling is a common cause of breakage.
This method provides a basic framework for using a fire in a pit to fire ceramics, focusing on the fundamental steps of preparing the heat, placing the work, and protecting it during the firing process.
