Thursday, April 22, 2010

Tweaking my favorite ash glaze

I love lorio ash. It's got a beautiful color. Behaves like a great ash glaze and I modified it down to cone 6 and that version webs beautifully and never runs past where I applied it. However when I tried my version of lorio ash at PNW it ran like it was training for the Olympics. It reinforces the saying that "glazes don't travel". Truer words never spoken. Every kiln is unique. Every kiln fires differently. Heck, at the last studio I was at they had three kilns - some glazes fired differently in those three kilns sitting in the same room. It's no surprise that a version of a glaze I had refined to fire in the kilns at one studio totally bombs out in a different kiln. So that sends me back to the drawing board.

Time to reformulate a version of lorio ash for the kilns I am using now. I am starting the same way I always start - with the original recipe. I have the base recipe and two data points, the kilns at PNW fire at cone 6 and the version I had of this gaze while tweaked for cone 6 is melting too much. So the recipe I am after is somewhere between the base recipe and the version I had been using. Knowing the boundaries I created a table:



10 (base)

9

8

7

6 (my current version)

Alberta Slip

43.5

43.5

43.5

43.5

43.5

EPK

13.9

11.9

9.9

7.9

5.9

Whiting

29.6

29.6

29.6

29.6

29.6

Wood Ash

13.9

13.9

13.9

13.9

13.9

Grestely Borate

0

2

4

6

8

RIO

3

3

3

3

3

TiO2

6

6

6

6

6



As you can see I kept the moving parts down to a two; EPK and GB. I will be testing 4 of these soon. The fifth one I already tested, my current version and it ran.


While I was mixing up glazes I mixed up an oldie but goodie - Reitz Green. I freakin' loved this glaze in the past. But never brought it down to cone 6. I know the kilns at PNW are higher than the kilns I am used to so I am hoping I can get this glaze working. I also swirled up a quick batch of Pinnel Celadon. I haven't found a celadon I like yet.


Oh and before I forget - the new version of my glaze db web site is almost complete. Just finishing up the UI now. Putting in things like pagination and print pages.


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