Ceramics/crazing

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Expert: Leisha Hiester - 12/3/2008


Question

typical crazing
Hi,

I have spoken to you before about problems with crazing. It seemed to rectify itself when we upped the temp of the bisque fire and changed from Duncan glazes to Gare. The problem has returned and the pieces are taking months to craze! One of them have just sat on my shelf in my studio and had been fine then all of a sudden there is crazing. I'm really quite fed up and stressed over the whole thing.

I'm buying my own kiln in the next few weeks and will be pouring my own slip etc. Am I less likely to have this problem with porcelain? Would I be better off using slip or solid clay. I'm making small flat objects. Can you still get the lovely strong reds with porcelain clays or do they fire at too higher temp?

Any thoughts on visible crazing months after firing and sitting on a studio shelf?? I have heard that all earthen ware will eventually craze is this right?? I store my pieces together in individual sealing bags (like you would get from a bank, could the slight knocking of the pieces together cause a problem? The woman that fires them has told me that it's because I am applying my glaze too thickly.

Thank you I'm getting very frustrated by the whole thing.  

Answer
Kerry,
Boy, am I glad you're getting your own kiln. It really is the only way to control the process fully and know exactly what's going on.

All earthen-ware does not eventually crazed if it is fired properly. Not to sound like a broken record, but if you ensure that your firing to vitrification and that your glaze matches the clay body, if your kiln is firing properly this should not happen.

If you were firing your glaze too thickly you'd have bubbles too.

Please let me know once you get your kiln & I'll help walk you through a good procedure.

Leisha

Leisha Hiester

Expertise

Inquiries about ceramics, pottery, clay and art in general.

Experience

21 years in ceramics and clay, teaching, producing and selling.

Education/Credentials
College, courses, teacher and worked in production studios.

Past/Present Clients
Private collections

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