Glaze defects in porcelain sculptures can significantly impact their aesthetic and structural integrity. Understanding the root causes and solutions is essential for artists and collectors alike.

1. Glaze Cracking (Crazing or Dunting)

- Cause: Uneven cooling or thermal shock during firing creates fine cracks in the glaze.

- Fix: Adjust kiln cooling rates or use compatible glaze-clay combinations to minimize thermal stress.

2. Pinholes (Bubbling or Blistering)

- Cause: Trapped gases from organic impurities or improper glaze application escape during firing.

- Fix: Ensure thorough bisque firing, sieve glaze mixtures, and apply thinner, even coats.

3. Glaze Crawling

- Cause: Contamination (dust or grease) or overly thick glaze application causes uneven shrinkage.

- Fix: Clean surfaces meticulously and apply glaze in controlled layers.

4. Color Inconsistencies

- Cause: Inaccurate firing temperatures or uneven glaze mixing.

- Fix: Calibrate kilns precisely and mix glazes thoroughly before application.

5. Shivering (Flaking Glaze)

- Cause: Glaze contracts more than the clay body, causing flaking.

- Fix: Reformulate glaze recipes to match clay expansion rates.

Repair Techniques:

- For minor cracks, use epoxy resin tinted with ceramic pigments.

- Sand and reglaze affected areas for pinholes or crawling, followed by refiring.

Preventive measures, such as meticulous material preparation and controlled firing, are key to minimizing defects. Mastering these fixes ensures flawless porcelain artistry.