Home Wild Clay Glaze Testing
Dec 11
The ECU Ceramic Guild has been working on dinner sets for a luncheon hosted by the Chancellor’s Office. As part of the process, we decided to do a test firing of a few sets in the soda kiln. I took the opportunity to test out a few wild clay glaze blends during this firing.
I tested five glaze recipes:
5NCW – Wild Clay 60%, Wood Ash 20%, Neph Sy 20%
14NCW – Wild Clay 20%, Wood Ash 20%, Neph Sy 60%
13NCW – Wild Clay 20%, Wood Ash 40%, Neph Sy 40%
13FCW – Wild Clay 20%, Wood Ash 40%, Feldspar 40%
15NCW – Wild Clay 20%, Neph Sy 80%
All of my test pieces were placed at the bottom of the kiln. We weren’t able to fully load the front shelves, which caused the top of the kiln to fire much hotter. Despite the bottom not reaching temperature, I was really happy with how all of the tests turned out in the soda atmosphere. I love the variations on 15NCW, the crazing, carboning, trapping, and the rich iron coloration. As for 14NCW, I like how the glaze is matte and crystallizes, creating a lovely surface.
Nov 30
Using a small batch of wild clay I collected, I set out to create a high-fire glaze. I started by experimenting with a Triaxial Blend, aiming to keep the materials as natural as possible. I tested two different combinations:
(1) Wild clay, wood ash, and potash feldspar
(2) Wild clay, wood ash, and nepheline syenite
It had been a while since I last mixed a large number of small glaze tests, so it took me a bit to get back into the rhythm. After a few hours of mixing and prepping the test tiles, everything was ready to go. The results showed a wide variety of surfaces: matte, semi-matte, and glossy. Some glazes pooled beautifully into the ridges of the tiles, emphasizing the texture. Many of my favorites came from the second blend using neph sy.
Moving forward, I plan to test these glazes in other atmospheric firings, such as soda and wood, and eventually apply them directly onto the wild clay body itself.
