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Ceramic Calculator Platform
Crack Risk Calculator
Clay & Shrinkage
claycalc.com
Clay & Shrinkage
Crack Risk Calculator
Assess the cracking risk of a ceramic piece during drying based on form, clay type, and conditions.
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Enter your measurements above and click Calculate.
Understanding the Risk Score
The crack risk score (0–15) combines six independent risk factors, each scored based on research and studio practice:
| Factor | Low Risk | High Risk |
|---|---|---|
| Wall thickness | ≤ 6mm | > 25mm |
| Thickness variation | ≤ 10% | > 50% |
| Drying speed | Slow (covered) | Fast (heat/fan) |
| Clay type | Earthenware | Porcelain |
| Joined sections | No | Yes |
| Humidity | > 50% | < 30% |
Scores 0–3 = Low Risk. 4–6 = Moderate. 7–10 = High. 11–15 = Very High. Follow all displayed recommendations to reduce risk.
Frequently Asked Questions
Why do thick and thin walls crack differently? expand_more
Uneven wall thickness causes differential drying — thin areas dry and shrink before thick areas, creating internal stress that leads to cracking at the transition point.
How can I prevent cracks at joined sections? expand_more
Score and slip joining surfaces thoroughly, ensure both pieces are at the same moisture level (leather hard), and compress the joint well. Wrap the joined area with plastic to slow drying at that point.
Is porcelain harder to dry without cracking? expand_more
Yes. Porcelain has very low plasticity compared to stoneware and is extremely sensitive to uneven drying. It requires slow, even drying — typically covered for 24–72 hours before any exposure to air.