Monthly Tech-Tip | No tracking! No ads! |
These DFAC test disks (drying performance) show that minor additions of grog do not reduce the fired shrinkage of this medium fire stoneware much. Nor do they improve its drying performance. Even at 20% grog, although the addition has reduced drying shrinkage and narrowed the crack somewhat, it is still there and even resembles the zero-grog version. A possible reason is that this body is coarse-particled, having a relatively small total particle surface area. The addition of the grog has significantly increased the total area.
Materials |
Grog
|
---|---|
Tests |
Drying Factor
The DFAC Drying Factor test visually displays a plastic clay's response to very uneven drying. It is beneficial to show the relative drying performance of different clays. |
Glossary |
Drying Performance
In ceramics, drying performance is very important to optimizing production. More plastic clays shrink more and crack more, but they are also better to work with. |
Glossary |
Drying Shrinkage
Clays used in ceramics shrink when they dry because of particle packing that occurs as inter-particle water evaporates. Excessive or uneven shrinkage causes cracks. |
Glossary |
Grog
Grog is a term used in ceramics to describe crushed brick (or other fired ceramic) aggregate that is added to sculpture and structural clays to improve drying properties. |
Buy me a coffee and we can talk