When it was first manufactured in Europe, porcelain was considered more valuable than gold. It takes practice to work with porcelain. The results, however, are worth the effort and provide a high-quality product that stands the test of time with its beauty and durability. Porcelain turns translucent when made quite thin and fired correctly. Porcelain must be bisque-fired to a low temperature and then glazed to prepare it for the final high-temperature firing. Porcelain can be fired to the highest temperatures in the ceramic industry.
Things You'll Need
Computerized kiln (with built-in pyrometer and read-out)
Bisque the porcelain items you have made once they are completely dry. Load the kiln and set the shutoff at the recommended bisque temperature, which can range between 1600 and 2000 degrees Fahrenheit. Preheat for a few hours while keeping the top peephole open. Keep the temperature below 250 degrees and wait until there is no more steam exiting the kiln. This may take several hours.
Set the kiln to raise the temperature about 7 degrees per minute until you reach the correct temperature. The kiln will automatically shut off when it is reached. Let it cool for at least a day.
Unload and glaze the bisque-ware. Make sure that the kiln shelves have a coat of kiln-wash on them. Use a brush to apply more to keep the clay or glaze from sticking when in a molten state. Follow the manufacturer's instructions when mixing kiln-wash powder with water.
Load the glazed porcelain into the kiln and close the lid. Set the kiln to shut off at the temperature prescribed by the manufacturer. Depending on the porcelain, this may be anywhere from 2000 to 2500 degrees Fahrenheit. Keep the top peephole open. Keep the temperature under 250 degrees for the first hour.
Raise the temperature by setting the kiln to raise the temperature by 10 degrees per minute. Check the kiln every half hour to make sure it is firing correctly. Don't rely on the computer completely. Always double-check the computer read-out using your hand-held pyrometer. Hold the tip inside the kiln through the peephole to get a reading.
Wait until the kiln shuts off at the exact temperature, and let it cool for two to three days before opening the lid.