If you've just started using your own kiln or your using a firing service, it's important to know a few key things! Here are our four best tips for beginners firing in a regular oxidation (electric) firing.
Tip 1
Know your firing ranges. In ceramics there are 4 basic firing ranges;
1. Bisque – this is a first firing at 1000°. A bisque fire will stabilize you work, make it stronger to handle and prepare it for the glazing process.
*It's important to know: You can add a glaze AFTER Bisque Firing. Before the bisque firing is a great time to paint on underglazes.
After a bisque fire you will proceed with a 2nd fire at one of the following temperatures.
2. Earthenware –firing range 1000° to 1150°.
3. Mid Fire –firing range 1150° to 1240°.
4. Stoneware – this is the highest firing temperature. Firing range 1240° to 1300°.
Tip 2
Know your clay. Like with glaze, each clay type will fire at an optimum temperature. Therefore, clay must be compatible with the glaze (in terms of temperature) and with a specific firing range in the kiln. For example;
Earthenware clay = earthenware glaze = firing temperature of 1000° to 1150°, also known as cone 04
Mid fire clay = mid fire glaze = 1150° to 1240°, or cone 5/6
Stoneware clay = stoneware glaze = 1240° to 1300° or cone 9/10
Handbuilding, sandy or 'groggy' clays will usually have a large firing range so you can fire these at any of the three temperatures, however most of these vitrify best at stoneware temperatures.
A clay’s firing temperature is usually written on the bag so keep this information handy. Or check with us at Northern Rivers Pottery Supplies.
Tip 3
Bisque fire before you glaze your project. While it is possible to single fire, this can put pieces at risk and demands different programming for temperature rises in the kiln. It is not advisable in a shared or community kiln due to the risk to the kiln and other peoples work. At Northern Rivers Pottery Supplies and most community kilns, we do not single fire. Therefore, we only fire clay work that has been bisque fired. Please note, this is not the case for underglazes.
Tip 4
Mark your work. When firing your clay work in a public kiln it is important to make your work identifiable. If you are looking to find a unique mark there are many options to sign your work, a Xiem Stylus Tool, needle tool or clay stamps or letter stamps are all great for adding a signature to your work. This will make your work easy to identify and minimize the possibility of losing your piece.