I remember not seeing the point in taking science classes beyond the basics – especially as an artist. I must say, however, I am glad that I did because I have sure used more than I thought I would in my art! I remember when I first started glaze formulation at Houghton. I was a little overwhelmed as I tried to learn the different elements that go into glazing and learning what material is what and how they can be used in glazing. My head started to spin when I was figuring out the roles of frit, flints, fluxes, colorants, water ratios etc. Sometimes people ask me what goes into a glaze and if they really want to know I will explain, but usually start to lose people. I still get lost myself! I have come to really enjoy the glaze formulation process. Aside from feeling smart, I like learning about the process and the science behind each material.
My base glaze consists of Ferro Frit 3110, Zinc Oxide (calcined), Silica, Kaolin (EPK), and Titanium Dioxide. These raw materials will give me my basic crystalline formulation. To achieve color, I add a percentage of those colorants to the base glaze. The materials I am currently using to achieve color are copper carbonate, cobalt carbonate, rutile, red iron oxide, titanium dioxide, tin oxide and nickel oxide. Of course there are plenty more out there, but those are a few for now. As you can see I wear a ventilation mask. It is pretty important to wear one when working with these materials in their raw and dry form. The dust that stirs up is not good to breathe in, especially silica dust. This mask was designed specifically for protection from silica and other harmful dusts. I do have goggles and latex gloves that I wear too for added protection, plus it greatly helps my hands from drying out so quickly!
Using my triple-beam scale, I have to zero out the container to I can get an accurate read on the measurement. Once I do that, I set the scale to the desired weight and then start filling the container with the first ingredient until it reaches that weight. Then I move on to the next material – zero out the container, set the weight (in grams) and measure it out. As I measure each raw material, I add it to my first container until each dry ingredient is all in the same bucket. That is essentially the glaze right there in the raw form. Then I add water to the dry mix and stir that into a nice creamy mix. This is usually about the consistency of half and half cream. Next I pour the glaze through a mesh sieve (200 mesh is the best) and use a rubber spatula to break any clumps down as it passes through the mesh. This is a very important step. It insures that the glaze is fully mixed and smooth without lumps! I pass the glaze through the mesh twice. Once that is finished, I have completed mixing a glaze and it is ready for use! Then I repeat the process with my next glaze adding different colorants to the next batch. It is pretty amazing to think that this soupy, chalky looking mixture fires to form such beautiful crystals! My first glaze firing is scheduled for this week, so stay tuned to see how my glazes turned out. I just hope I mixed everything correctly!