|Monthly Tech-Tip |
These disks concentrate the solubles on the outer edge (because of the way they are dried). Soluble salts can enhance the visual appeal of a fired clay but they can also do the opposite.
In ceramics, certain compounds in clays and glazes can dissolve into the water, then on drying these are left on the surface.
A common problem with dry and fired ceramic. It is evident by the presence of a light or dark colored scum on the dry or fired surface.
SOLU test to evaluate and compare the solubles salts content in clay bodies and materials