Monthly Tech-Tip | No tracking! No ads! |
The freshly thrown piece on the left front is a medium-temperature plastic stoneware body. Its color comes from a natural iron-bearing clay in the recipe. However, that red clay is becoming much more expensive and difficult to obtain because of trucking availability and cross-border issues. We are investigating the addition of iron oxide to a blend of buff burning materials (which can be tuned to match the working and firing properties of the original body). A 3% iron oxide addition is producing the same fired color. But raw color also needs to be matched. The answer is a blend of red:yellow:black iron oxides. The 3% iron addition in the rear centre piece is a 50:50 mix of red and yellow iron oxides, clearly it is too red. The right front piece is a 40:50:10 mix of red:yellow:black iron oxides. This is getting closer, for the next trial we will try more black and less red.
Materials |
Iron Oxide Black
|
---|---|
Materials |
Iron Oxide Yellow
|
Materials |
Iron Oxide Red
Red iron oxide is the most common colorant used in ceramic bodies and glazes. As a powder, it is available in red, yellow, black and other colors. |
Buy me a coffee and we can talk