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#1 AMI



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Posted 27 March 2017 - 06:51 AM

Why do I get cracks in the glaze after the fire? Any suggestions

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#2 Chris Throws Pots

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Posted 27 March 2017 - 10:04 AM


I can't see the cracks you're referring to in the picture, but a typical cause of cracks developing in the glaze during cooling/after firing is crazing. Crazing is caused by improper fit between the glaze and the clay body. During the cooling, both the clay and glaze shrink. Crazing occurs when the glaze shrinks more than the clay body. Make sure your clay and glaze are both rated for maturity at the same cone. IE If you're using ^04 clay, use ^04 glaze; using ^6 clay, use ^6 glaze. If you're mixing your own glaze you could try to adjust the recipe for a better fit. If you're using a commercial glaze, maybe try a different product. 


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#3 Bob Coyle

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Posted 29 March 2017 - 10:58 AM

When I logged in, I saw only one reply to your post. The reason  is that  Chris pretty much gave a complete answer. Glaze "fit" problems are a reality for all of us who work with clay. You need to follow Chris's advice and work through the problem. 



PS If you are new to clay, your piece looks pretty nice. If you get a little crackle in the glaze of a non-functional object, just think of it as a "feature".  :)   and work from there. The whole ceramics form of Raku rises or falls based on the intentional crackle pattern of the glaze.                  

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