Monthly Tech-Tip | No tracking! No ads! |
Knowing the statistics of a pro sport can make one feel like an expert. But there is no substitute for actually playing! Likewise, taking the time to actually slurry up a clay body and hand-make and fire ware using it is the way to really notice it’s physical and firing characteristics. Engineers call this characterization of a body. I make coffee mugs, doing it the same way each time - so I notice differences. Notice what these cone 10R ironware mugs tell me. The rims are warping oval, the color is dark and solid and the foot is plucking: The body is too vitreous. I felt excessive coarse particles during throwing and trimming - and even on the fired rim. When pulling the handles splits formed, indicating low plasticity (this was also evident during throwing, I was unable to pull the walls as thin as normal). Dry strength is low, the lower handle-join dry-cracked along the convex side. The inside glaze is also revealing very high iron speckle (likely from the coarse particles).
If you are trying to use local clays for brick or tile or even pottery production, characterizing the available materials is the first step. But how? This is the kind of data a lab might return - perhaps you wonder about its value? We feel traditional ceramics technology is fundamentally relative. A history of many reports like these, in context with other data, might be good for mining companies to determine if new stockpiles have any shifts in certain specific properties. Or a tile company evaluating a new ball clay. But as a way to understand the utility of a clay for a specific ceramic purpose, this contextless report is of little use. For example, the physical properties, the whole reason for using a clay, are unrelated to the chemistry. This is also a tunnel vision view, looking at only one temperature. On the other hand, simple procedures, like the SHAB test, provide a hands-on way to understand what a clay actually is.
Glossary |
Characterization
In ceramics, this normally refers to the process of doing physical or chemical testing on a raw material to accurately describe it in terms of similar ones. |
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