Yes, air dry clay does become hard.
Air Dry Clay Hardness Explained
Air dry clay, as the name suggests, hardens by air drying rather than being fired in a kiln. The hardness achieved by air dry clay is considered to be earthenware hardness after approximately 24 hours, depending on the thickness of the project.
Factors Affecting Hardness
- Thickness: Thicker pieces of air dry clay will take longer to dry and reach their maximum hardness.
- Environment: Humidity and temperature can affect the drying process.
- Drying time: According to the reference, air dry clay reaches earthenware hardness in around 24 hours, but this can vary based on the project.
Working with Air Dry Clay
To avoid your clay project drying out too quickly, or if you need to work on it over several sessions, you can use the following method:
- Wrap the clay in a damp tea towel.
- Cover it with cling wrap to create an airtight seal.
This will help keep the clay moist and workable for a longer period. The reference suggests that this is a great technique if you need to pause working on your piece and return to it later.
Hardness Comparison
| Clay Type | Hardness | Firing Required? |
|---|---|---|
| Air Dry | Earthenware | No |
| Fired | Much Harder | Yes |
While air dry clay becomes hard, it does not achieve the same level of hardness as clay that has been fired in a kiln. This table illustrates this difference.
