A crucible kiln is a furnace designed for use with durable containers known as crucibles to melt materials like glass and metal. Molten materials can be worked to make or repair a variety of goods and crafts. A kiln of the correct size and temperature range is critical for successful work, as temperature problems can cause problematic chemical reactions inside the crucible and may make the materials weaker. Craft and industrial suppliers provide a range of kilns for different applications, along with crucibles and other necessary supplies.
The crucible kiln has a chamber designed to accommodate one or more crucibles filled with materials for melting. These crucibles can be made from a variety of heat-resistant materials that can endure the very high temperatures inside the kiln while evenly transferring heat to their contents. They may be made from ceramics as well as other materials, depending on how they are to be used.
Operators can add the materials they wish to melt and set a firing cycle on the crucible kiln. It will reduce solids to evenly melted materials that can be worked directly out of the kiln by lifting the lid. This may be necessary for projects where the material needs to stay hot to remain workable. Other crafters may grip the crucible with tongs and pour the contents into molds to create cast products.
Many have options to save firing cycles for specific activities. The operator can use preset programs or design new ones for various projects. The kiln's size and layout determine the size and shape of the crucibles it can accommodate. Most do not come with crucibles, but it may be possible to purchase models specifically designed to work with a particular kiln. Props and blocks to support crucibles and hold them at the right height are also available.
Working around a crucible kiln requires caution, because the kiln and contents can get very hot. It needs to be installed in a heat-safe area with adequate ventilation and clearance to protect people and property. Many have indicator and warning lights while in operation to alert people to the risks of handling or opening the kiln, and warning signs can also be posted around the kiln for extra safety. Protective garments and eye wear should be worn around the crucible kiln at all times in case of heat, splash back, and other issues that may arise while it is in operation.