the making of kohiki -1

Finally! It looks like it's all OK?
The furrow in snow series has been a real struggle... (just because I lack scientific understanding of the materials!)

First of all I mix clay and use Terracotta: low-firing red clay, in it. The maximum temperature for the clay is 1180 but I usually fire to 1260 with other clays that I've been using. All my glazes are designed for this temperature, but if I go this high this mixed clay body starts bubbling.
So I had to drop the temperature a little bit to avoid this problem, which brought another problem: the glaze doesn't mature. All the glaze has a temperature that needs to be reached. The glaze consists of three elements: glassy material to cover the surface and body material so that glaze fit on the clay body and 'flux' to melt these materials. By combining the three elements (from lots of raw materials!) we make a glaze to get a desired surface.
Mine for this series is supposed to be a very simple one: transparent glaze (but there are so many 'transparent' surface and I didn't want shiny one or runny one. I wanted warm one that goes a bit opaque where it's thicker.)
Anyway, back to the story, to mature the glaze at a lower temperature I had to alter the recipe. 
Altering the recipe in ceramics is not as easy as doing it in cooking. I always wonder if there's any 'super mad ceramicist' who can tell from the recipe how the glaze behaves and looks without making it. I think there are many who can roughly guess what might happen, but I don't think anybody can tell exactly. (Anyway that's the fun part of ceramics.)
Anyway as I can't 'calculate' glaze I just mixed some combinations. I got a good recipe but at the same time got another problem. It's because the new series has got a layer of slip between the clay and the glaze.



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