Having previously discovered the dramatic effects of a reduction atmosphere on crystalline glazes containing titanium dioxide, I made a little kiln load of pots, glaze fired them, and then put them through another firing where I introduced cooking oil into the electric kiln at one drip per second as the kiln cooled from 800 to 620 Celsius (1472 - 1148 F). The results were most interesting, especially so if you saw the pots before and after the reduction firing. Let's do just that!
|Here is the same pot after the oil drip reduction firing, with white and green crystals on a purple background... amazing really!|
|More of the green, white, and purple... what fun!|
|Here is another pot from the firing, also with the rutile glaze variation.|
The whole thing of what is "right" or "wrong" in the look of a crystalline glaze intrigues me. After all, I am sure that the first crystalline glazes occurred as a frustrating glaze fault rather than as something intended, and yet it has not taken people long to make rules! Some crystalline glazers would label a crystalline glaze, where most of the crystals touched, as being "over nucleated", and they might aim for between 3 and 5 large and spectacular crystals on their pots. Others are happier with an even coverage of much smaller crystal formations.
I do think that there is still a great deal to be explored with crystalline glazes. Crystalline glazes are runny by nature, and want to form waterfalls down the side of the pot when at high temperature! Could this be used expressively instead of caught in a catcher and ground off?
|Playing with glaze runs!|
|Crystals as texture.|
|This little crystalline pot has a matt surface.|
|Crystalline glaze with wood fired reduction and carbon trapping.|
Fear is the enemy here. The variety of fear that leads to rule making, the following of strange doctrines, intolerance, selfishness, and, ultimately, to ignorance!
Not sure why I went away on that tangent, put it down to too much coffee! I have been firing a crystalline glaze firing overnight and made an early start today to watch temperatures as the kiln came up towards the peak of the firing. It is nearing the middle of the day now and I will be able to shut off the kiln soon. This load is mostly crystalline bowls. I usually have a high failure rate with crystalline bowls (getting the glaze the right thickness is very important), and I need to do a lot of tests and firings in order to improve that. If it was too easy, it would not be so fascinating!