Defect · Cooling
Shivering
Also called: flaking
Glaze flakes off the piece, often along rims and edges, leaving sharp bare spots.
- Appears at
- Cooling
- Severity
- Structural
- How common
- uncommon
Causes
Most likely
- ·Glaze thermal expansion is significantly lower than clay body
- ·Glaze is under compression and releases by flaking
Prevention
- ·Increase flux (Na2O, K2O) to raise glaze expansion
- ·Reduce silica in the glaze
- ·Test glaze on multiple clay bodies to characterize fit
Can it be fixed?
Not reliably — this one is prevented, not repaired. A cracked or bloated pot is a test tile now.
Materials involved
Glaze materials whose chemistry sits behind this defect — each links to its reference page.
Questions
- Why does shivering happen?
- Most often: Glaze thermal expansion is significantly lower than clay body. Other causes: Glaze is under compression and releases by flaking..
- Can shivering be fixed?
- Not reliably once it has happened; the fix is upstream, in prevention.
- How do I prevent shivering?
- Increase flux (Na2O, K2O) to raise glaze expansion. Reduce silica in the glaze. Test glaze on multiple clay bodies to characterize fit.
Sources. Compiled from Claybench's defect reference — the descriptions, causes and remedies that appear consistently across standard ceramics references and studio practice; no single source. It is the same reference the photo diagnosis tool reasons over. Where the Wikibooks Ceramicware Defects Handbook covers a defect it is linked above.
Not sure which defect you're looking at?
Claybench can read a photo of the pot against this same reference and rank the likely causes for your clay, glaze and firing.