•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com

Sign-up at https://insight-live.com today.

Sulfate Scum


A yellow coloration can appears on the dry glaze surface, or on the bisque clay surface on the opposite side of a vessel wall that has just been glazed. The coloration does not appear immediately, but some time during the dryout of the piece. This is a product of soluble or partially soluble sulfates in the clay which, when given extended contact with the water from the applied glaze, dissolve and migrate to the surface with it. This phenomenon can happen even with porcelains and it is the product of drying the ware too slowly. In industry, care is take to dry ware quickly so the solution and migration does not occur. This can be done by heating the ware or putting it in a drying chamber immediately after glazing.

Out Bound Links

  • (Glossary) Efflorescence

    A term describing the whitish or brownish scum (de...


By Tony Hansen




Feedback, Suggestions

Your email address

Subject

Your Name

Message


Copyright 2003, 2008, 2015 https://digitalfire.com, All Rights Reserved