Air dry clay dries by evaporating water from the clay body into the surrounding air.
Understanding Air Drying
Unlike traditional pottery clay that requires firing in a kiln at high temperatures, air dry clay is specifically formulated to harden without heat. The primary mechanism is the simple process of drying. As water leaves the clay, the particles bind together, causing the object to shrink slightly and become rigid.
The Drying Process
The process is straightforward:
- You create your project using the clay.
- You expose the clay object to the air.
- Water evaporates from the surface and eventually from the interior of the clay.
According to the reference, this type of clay doesn't need to be baked in an oven or kiln because it will dry to earthenware hardness in the air.
How Long Does It Take?
The time it takes for air dry clay to fully dry can vary. Based on the reference, you should let it dry for around 24 hours.
However, several factors can influence the actual drying time:
- Thickness: Thicker pieces take much longer to dry completely than thin ones.
- Humidity: Higher humidity in the air slows down evaporation.
- Temperature: Warmer temperatures can speed up drying.
- Airflow: Good air circulation helps water evaporate faster.
- Size of the object: Larger objects typically have more moisture to release.
While 24 hours is a general guideline for thinner projects, thicker or larger items might require several days to ensure they are dry all the way through.
Tips for Air Drying Clay
For best results and even drying:
- Place the clay piece on a porous surface (like cardboard, wood, or a drying rack) that allows air to circulate underneath.
- Turn the piece occasionally if possible, especially thicker ones, to help all sides dry evenly.
- Avoid drying too quickly (e.g., with a direct heat source like a hairdryer or fan), as this can cause cracking.
Once the clay is completely dry, it reaches its hardened state.
