Kiln Firing Results, 


In this kiln I fired several sets of mugs to try out new glazes that I had tested in the previous firing. There are 5 to ten ingredients in a formula and each has a particular effect on the color, opacity and gloss, durablity, etc. Most glaze formulas are calculated to total 100 so that they can be compared. Sometimes I begin with a recipe/formula from a book and alter the ingredients to suit the pots I make. If the glaze will be used on my functional pots, I first enter the recipe in a glaze analysis program to see if the Silica and Alumina ratios are in the range of a stable glaze.

After I have tinkered around with the formulas, it's time to test my assumptions. I use a gram scale to weigh 200 grams total in each dry weight batch formula, which makes about 2 cups of liquid glaze. I mix each batch with water, screen, and apply to bisqued clay tiles, then fire to Seger cone 7 / 2230 F. with my own ramp schedule that includes controlled cooling, in a Skutt 10-27 electric kiln.  

 

before firing

after firing

My version of Xavier Jade

Mosley Olive Matte & White Liner

It often takes several trials to get the results I'm seeking. When I finally get a good test result I weigh out a 2000 gram batch to try on bowls or mugs in the next firing. These are mugs with my latest 2000 gram trials. I didn't expect so much blue in the overlap of Butterscotch over RR Black.

My version of Butterscotch with Ron Roy Black #3 Inside.