Last post I was talking about my love of reference books…and about liking to read dictionaries. A few posts before that I was discussing the mysteries of cracked work and Failure. Wellnowdonchaknow, both issues came up when my clay buddy, Yumi asked for help understanding why this one cup of hers split in half in an otherwise beautiful glaze load of her lovely – and whole – pieces. Here’s a story of connections made.
No matter how chill I might seem about cracks, don’t you buy it!!! Sure, I might write about Zen Acceptance and Metaphor, sounding all philosophical and detached. That’s me trying write myself some peace. Ultimately, though, I’m still upset because I just don’t understand what happens when works seem to fail so randomly. If I don’t understand it, how can I avoid it?
I had one clue from my Cracks Gone Sproing experiences: the pieces all had thicker than usual inside glaze applications. It made me seriously wonder about inside and outside surface tensions, but that’s as far as I got.
I kept on the alert, and often certain words, concepts, examples around my particular cracking problem repeated: Quartz Inversion, Cristobalite Inversion, Cooling Dunting. Tell me more!
It took years though, and in the face of No Ready Answers, one turns it over to the whimsy of the Kiln Goddesses, shrugs her shoulders and says, “Mama said there’d be days like this.”
And yet it turns out my one clue – uneven interior/exterior glazing – was actually a valid lead.
In true clay nerd fashion, one day I followed up on this lead by once again reading a dictionary: The Potter’s Dictionary of Materials and Techniques. A gotta have on the bookshelf!
I started with the 9-page extensively illustrated entry CRACK.
Which led me to Cracks D and E in Glazed Ware.
Which led me to DUNTING and specifically to Cooling Dunts due to the cristobalite inversion
Which led to understanding a key expanding/shrinking change clay and glazes go through differently as the kiln heats and cools. I think I pegged my problems, which are a Perfect Storm of firing situations: Uneven clay walls compounded by uneven glaze/non-glaze applications compounded by uneven heating and cooling compounded by physical location in the kiln compounded by Luck of the Kiln Goddesses. That covers it.
Have I lost all you non-clay readers? Sorry. A clay nerd’s gotta do what a clay nerd’s gotta do.
To bring it back round, when I saw Yumi’s nearly textbook photo of the dictionary descriptions and heard her questions, it all came clear. I chimed in with my thoughts on her casualty. Hope it helps
So, as I was just saying, problems are good, so is reading up, and so is taking them to the next level!
~Liz Crain, who will certainly have more to say about this as she applies her new-found understanding to her new works and refires.