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URL: Bacterial survival studies done on crazed glazes had surprising results. But also oversights.
Click the link below to go to this page
https://ceramicartsnetwork.org/ceramics-monthly/ceramics-monthly-article/Techno-File-Dirty-Dishes#
This article, Techno File: Dirty Dishes, argues that the dangers presented by microbes on crazed glazes are over-blown and unwarranted. And that pores and surface irregularities in even uncrazed glazes could also harbour bacteria if surfaces are not cleaned. But, it fails to address a number of factors.
-The possible presence of a porous body below (that could harbour pathogens).
-Regulatory bodies regard it as a compromise of the integrity of the glaze and the ability to clean the surface properly.
-A dramatic reduction in ware strength accompanies crazing.
-No commercial hobby glaze manufacturer recommends the use of crazed glazes on food surfaces.
-That it is usually easy to fix.
Related Information
This is crazing. This is functional ware. Is this good?
AI generated with the prompt: A crazed glaze on a stoneware pottery mug.This picture has its own page with more detail, click here to see it.
This glaze is "stretched" on the clay so it cracks. When the lines are close together like this it is more serious. If the effect is intended, it is called "crackle" (but no one should intend this on functional ware). Potters, hobbyists and artists invariably bump into this issue whether using commercial glazes or making their own.
"Art language" solutions don't work, at least some technical words are needed to understand it. Crazing is a mismatch in the thermal expansions of glaze and body. Most ceramics expand slightly on heating and contract on cooling. The amount of change is very small, but ceramics are brittle and glazes are rigidly attached. If they are stretched on the ware cracks will occur to relieve the stress (usually during cooling in the firing but sometimes much later). All glaze and body manufacturers advise against crazing on functional ware.
Links
| Troubles |
Glaze Crazing
Ask the right questions to analyse the real cause of glaze crazing. Do not just treat the symptoms, the real cause is thermal expansion mismatch with the body. |
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