Wendy's Glaze Demo - the basics...
Very informative and gave me the feeling that I can do it.
Glaze temperatures can range from 700'C to 1300'C
E/W is lower, S/W is higher.
You can buy bought in glazes or mix your own - it's all about the application.
1. Slips
Slips are applied to greenware - they can be coloured and enable sgraffito to be used as a decoration. once fired, a glaze can be added over the top i.e. honey glaze (translucent plus manganese) or copper glaze ( translucent glaze and copper oxide)
2. Oxides
Oxides can be used on their own or as a colouring material, added to glaze.
Iron can be red or black
Copper is green
Cobalt is blue
Manganese is brown
The above has had iron and manganese brushed on near the top and copper brushed on at the bottom. The copper has all but disappeared. It was first fired to E/W but the iron didn't flux properly so it was re fired to S/W.
3. Engobes
Engobes have more China Clay content and is fired to E/W temperatures.
It is very matt and is applied to bisque ware. Underglaze can be added to engobes.
A positive is that it doesn't run.
4.Earthenware Glazes
Fired to a lower temperature
Bright colours
5. Stoneware Glazes
More earthy colours than bright.
High fired and good for outside pieces. Wendy adds silicon carbide to create bubbles. (about 3% to a kilo)
6. Lustres and Enamels
Added last as they are fired to a very low temperature (700'C to 850'C)
Looks shiny when added to glaze but matt when added to engobe.