1. Ceramics Basics

2. Cone refers to firing temperature.
Low , High

3. CONES
The Cones themselves are small pieces of specially formulated clay which begin to melt at specific temperatures.
PYROMETER
This is a thermometer capable of registering high temperatures.

4. WHAT HAPPENS AS CLAYS AND GLAZES ARE FIRED?
212° F Water boils to 392° F Clays lose water. 392° F Typical kitchen oven baking temperature. 705° F Chemically combined water leaves clay. 932° F Red glow in kiln ° F Quartz inversion
1112° F to 1472° F Cone 015 Organic matter in clay burns out.
(This is the temperature range we slump glass jars.)

5. 1472 to 1832° F. Cone 015 to Cone 07 Orange color in kiln
1472 to 1832° F Cone 015 to Cone 07 Orange color in kiln. Low fire earthenwares and lowfire lead glazes mature. Normal firing temperature for red bricks and terra cotta
(Glass begins to liquefy and Raku fire) to 2120° F Cone 07 to1 Yellow color in kiln. High fire earthenwares mature. Feldspars begin to melt.
(Low fire glaze and bisque fire) to 2174° F Cone 3 to 4 Bright yellow white color in kiln. Mid-range clays and low fire stonewares mature. High iron content clays begin to melt.
(We fire Cone 5 Stoneware and glazes) to 2345° F Cone 7 to 9 White color in kiln. Stoneware clays vitrify, feldspathic glazes mature. MOST STUDIO POTTERY IS FIRED TO CONE 9 OR LOWER.

6. 2345 to 2462° F Cone 9 to 13 High fire stonewares, porcelains vitrify.
3113° Silica melts
3722° Alumina melts
Our kiln is only capable of firing to Cone 10.

7. Temps we fire Glass Slump Glass Fusion
Raku and Pit (Stoneware Clay with high Grog)
Low Fire (05) (Low fire clay)
High Fire (5) (Low fire Stoneware)

8. Reduction
The rate at which ceramics or glass cools is known as reduction.
If it cools too fast it will crack and break.
A typical cone 05 cycle will take at least 24 hours to reach temperature and cool back down.

9. Kiln wash
Kiln wash works as a release agent. Paint wash on shelves to prevent glaze adhering to shelves or posts.

10. Shelves must be scraped and repainted on a regular basis to ensure longer life of the kiln.
A kiln used on a regular basis can last 10 to 15 years.
Decommissioned kilns can be scrapped and converted to Raku or pit kilns. Bricks can be used for other firing projects.

11. Green ware vs. Bisque ware
Once you have shaped your clay, you will let it dry.
Once clay has dried it is know as green ware.
Green ware must be fired before glazing. Once fired the bisque ware pottery is ready for glazing.
The tiles you used for testing glazes are bisque ware.

12. Glaze
Glaze is the coating on the exterior of ceramics. It melts at high temperatures to create a glass finish. Underglaze is essentially a tile stain and does not seal the ceramic surface.

13. Glazes come in all colors and finishes
Glazes come in all colors and finishes. Always read the label since the color you paint will change once it is fired.

14. Test Fire
Look at your finished test tile and record your results in your sketchbook.
Use this information as a reference when deciding which glazes to paint your ceramic work.