Quick Answer
Fully fired pottery can be identified by its hardness, which should reach a minimum of 5-6 on the Mohs hardness scale, and by its uniform color, which should be consistent throughout the piece.
Visual Inspection
When inspecting fired pottery, look for a uniform color and a hard, non-porous surface. If the pottery is not fully fired, it may appear soft, spongy, or have a waxy sheen. Check the edges and corners for any signs of uneven firing, such as discoloration or uneven hardness. A well-fired piece should also have a smooth, even texture.
Testing for Hardness
To confirm that the pottery is fully fired, perform a scratch test. Use a steel file or a piece of ceramic tile to scratch the surface of the pottery. If the file or tile does not scratch the surface, it is likely fully fired. If the file or tile scratches the surface, it may not be fully fired.
Firing Techniques
To achieve the best results, it’s essential to follow proper firing techniques. For pit firing, use a temperature range of 1000-1200°C (1832-2192°F) for 6-12 hours. This will ensure that the clay is fully vitrified, resulting in a hard, non-porous surface. For coil method firing, use a temperature range of 900-1000°C (1652-1832°F) for 4-6 hours. This will help achieve a uniform color and a hard surface. Regardless of the firing method, it’s crucial to monitor the temperature and adjust as needed to achieve the desired results.
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