Some iron clays bloat before reaching zero porosity, others do not

Monday 16th June 2014

A very fine particled low fire red burning terra cotta clay (Plainsman Redearth) fired at cone 2,3 and 4 (top to bottom). Notice the cone 4 bar is beginning the melting process (signaled by the fact that it is expanding). Yet it is not bloating as this type of raw clay normally would. The cone 2 and three bars have reached zero porosity also. Other clays that fire to very similar color begin to bloat long before they reach zero porosity.

Pages that reference this post in the Digitalfire Reference Database:

Vitrification, Porosity, Terra cotta, Bloating

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