Ceramic Glaze

I recently finished building an outdoor kitchen out of historic cream bricks from Fort Atkinson. This project involved a lot of brick cutting with a wet saw. It was incredibly dirty and unpleasant work; however one thing that struck me after a day of cutting was the water mixed with the dust from the cut bricks, and made a wet clay. I thought it was really cool that I was basically reconstituting clay that was originally dug up from Wisconsin a century and half ago.

As a potter, it got me to wondering more about the clay and its uses in ceramics. I have since learned that due to the high calcium and magnesium levels, it is unsuitable to use as a ceramic clay body, since both act as fluxes and lower the melting point enough that the clay starts to melt above 2000 deg F. Since then, I have been very interested in developing a glaze out of recycled cream bricks.

Thanks to research that has been done on this clay and the brick making process over 100 years ago, I have a very good idea of the exact chemical composition of these bricks. With my research into glaze chemistry, I was able to formulate some excellent glaze recipes with the addition of a few ingredients. To make this glaze, I ground a brick into dust using a belt sander. My goal was to maintain cream city brick as the main ingredient, and only add enough to make it a viable glaze. I recently got my first test pieces back from a cone 6 firing and was extremely happy with most of the results. I have run the successful samples through the boiling water to frozen water test multiple times, and they exhibited no crazing. These glazes contain 60% cream city brick dust by mass.
 

I am very excited to continue testing on these glazes, I would love to make pottery with a glaze made from brick scraps from my parent's historic barn, and it would be a great way to carry on the legacy of the many cream brick buildings that are being taken down each year. I am in the process of constructing a ball mill to ramp up my production of these glazes, and hope to post many more examples soon.