Definition:
Vitrification is the process of melting that different types of clay and glazes go through as they are fired. In a fully vitrified clay-body, the spaces between refractory particles are completely filled up with glass, fusing the particles together and making the clay body impervious to water.
- Check the manufacturer for the correct firing schedule
- Ensure your kiln is firing to the correct temp, old coils can cause problems
- Add glaze to the piece and fire it again at a higher temp
- Change clay-body for future pieces
Using an improperly vitrified clay-body can cause “crawling” and “pitting”, not all glazes will react the same