Two glazes. One crawls, the other does not. Why?

Wednesday 25th July 2012

The DIY glaze on the right is crawling at the inside corner. Why? Multiple factors contribute.

• The angle between the wall and base is too sharp. A thicker layer of glaze has collected there (the thicker it is the more power it has to impose a crack as it shrinks during drying). For the same reason, even prepared glazes can insight-live.com/trouble/1">crawl like this.


• The preparation of the slurry. This one shrinks more during drying because it has a higher water content.


• The recipe: Its high raw clay content which increases drying shrinkage. Calcining part of the raw clay would be an effective way to deal with this. Or doing a little chemistry to source some of the Al2O3 from materials other than clay (e.g. a frit having a higher Al2O3 content).

Pages that reference this post in the Digitalfire Reference Library:

Calcination, Suspension, Crawling

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