Tuesday, May 2, 2023

Making Hard Clay into Soft Clay the Easy Way


Watch this video to learn the easiest way to soften a bag of clay that is too hard to use. This method has a 100% money back guarantee.

There is a different method that people use to soften clay where they add some water to the pug of clay and then submerge it into a 5 gallon bucket of water and let it sit overnight. This method is way more difficult than it needs to be. Who has room in their studio or classroom for 5 gallon buckets of clay and who wants to lift all of those buckets or deal with wet bags of clay afterwards?  The method I present in this video is for those who want the easiest method that requires the least amount of effort. You could say it is for people who want to work efficiently or you could say it is the laziest way to do this.

Wednesday, August 17, 2022

Stull's Map explained by Matt Katz of Ceramic Materials Workshop

 As the title says, this video is the Stull Map explained. This video gives you an idea of what glazes will appear in certain areas of the map. Think of it as an overview of the territory of the Stull Map. To me this map is the starting point for creating glazes. I view it as indispensable in analyzing glazes and figuring out how to adapt them to fit my needs,

Friday, August 12, 2022

Plotting glazes on the Stull Map

This is the Stull Map. The vertical axis on this grid measures alumina. The horizontal axis on this grid measures silica. That white section in the middle labeled bright is where all of the durable glossy glazes are located. If you enter a glaze recipe into the website glazy.org it will automatically plot your recipe on a Stull Map.

There was a discussion on the Clayart Listserv group about the Rhodes 32 glaze. This is where Rhodes 32 lands on the Stull Map - it lands in the semi-matte region. Rhodes 32 has a problem with cutlery marking and the discussion revolved around how to correct that.

I used the glaze calculation feature on Glazy.org to map out four corners for a biaxial grid. The bottom left glaze is the original Rhodes 32 recipe. The top left glaze has added alumina. The top right has added alumina and silica when compared to the original. The bottom right glaze has added silica.

I used the biaxial blend option in Glazy to generate a 5x5 grid. If I were looking to explore this glaze I could mix up the four corner glaze recipes and then use Ian Currie's volumetric blending method to create the 25 glazes in this grid.

This is an example of how I use the biaxial grid method on the website glazy. Each glaze in this set of 25 glazes has the same fluxes in a .3 to .7 R2O to RO ratio. What varies is the amount of alumina and silica in each of them.

This type of grid can help you spot trends. The glazes on the left are matte. As silica is added they move into the glossy range. You can see that some of the matte glazes on the left are runny. That is what happens when a matte glaze is over-fired - it runs. But if you add silica to that same matte glaze, it turns glossy and you can see that happening in this grid.

This is the Stull Map for the biaxial grid set of mine. If you study this image, you will see that many of the glazes are in the matte and semi-matte region on the Stull Map. This corresponds well with my fired results. Notice that the glossy glazes that I generated with that grid set are plotted in the glossy area of this Stull Map.

I think of the Stull Map as a compass. It can help you spot the trends that happen in a glaze when you vary the amounts of alumina and silica in that glaze. The line between semi-matte and glossy is not a hard and fast rule where moving one small bit over that line from the semi-matte to the glossy region generates a glossy glaze. Rather what happens is that if you create a biaxial grid of your glaze, you can use it to spot the trends and then zero in on the results you wish to explore. Looking at the fired results of this grid has led me to make up a batch of glaze A2 because it is a lovely blue-green matte with crystals.