Cross section comparison between cone 04 terra cotta and cone 6 iron stoneware

Monday 15th June 2015

Both of these bodies have a range of particle sizes (from 42 mesh and finer). The glaze on the insight-live.com/glossary/119">cone 04 section (close-up on the left) is very well melted, but its interfacial zone with the body is narrow, it is basically just "stuck on" the surface (so it must be tuned to match the thermal expansion of the body to prevent crazing/shivering). The body is not developing any clearly visible glassy phases, meaning that any strength it has is purely a product of sintering. On the right, the interfacial zone of glaze-with-stoneware-body is wider. The body has incipient melting (tiny feldspar particles are fusing and beginning to dissolve into the surfaces of surrounding ones). The color has changed from red to brown.

Pages that reference this post in the Digitalfire Reference Library:

Terra Cotta, Clay Body Porosity, Vitrification, Sintering

This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.