Some bodies cannot be fired to even near zero porosity


Wednesday 13th May 2009

Bloating in an over fired middle temperature high iron raw clay (Plainsman M2). It is still stable, dense and apparently strong at cone 4 (having 1.1% porosity). But between cone 6 and 7 (top bar) it is already bloating badly. Such clays must be fired at low enough temperatures to avoid this volatility (if accidentally over fired). This clay only reaches a minimum of 1% porosity (between cone 4 and 5), it is not possible to fire it to zero porosity. This is because of the particulate gas-producing particles (it is ground to 42 mesh only).

Pages that reference this post in the Digitalfire Reference Database:

Bloating, Vitrification, Terra cotta, Body Bloating, Over firing


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.