Advancer 21 inch Half Shelf
A-21H
Fine grained, nitride-bonded silicon carbide. 1400ºC max.
21″ x 10.5″ x 5/16″ Half 10 Sided
53cm Half shelf x 8mm
ADVANCER® kiln shelves are the only silicon carbide shelves tested and recommended for use in resistance coil element kilns. At only 5/16-inch thick, ADVANCER® kiln shelves allow for significantly more stacking space when compared to conventional 5/8” and 1” thick cordierite kiln shelves. Put 6 ADVANCER® shelves in the height required for 5 cordierite shelves giving an additional 20% stacking space! At less than half the weight of conventional shelves, ADVANCER® kiln shelves are far easier to handle and lift in and out of the kiln with less stress to your hands and back.
Lower mass and faster heat transfer (greater thermal conductivity) means shorter firing cycles and reduced energy consumption.
While a 1-in-thick cordierite shelf has been the standard choice for electric kiln firings to cone 6 and above, it also consumes a lot of energy and stacking space. This is especially the case with 7 to 20-cubic-foot top-loading kilns, where space is at a premium.
Not only will an advanced Silicon Carbide shelf stay flat in this application, but its 5⁄16-in. thickness also allows for more stacking space and reduced energy costs. It is also easier to lift in and out of top-loading kilns due to its lighter weight. The initial investment for the shelf is significantly higher than cordierite, however, it is easy to realize a substantial return on investment when energy and productivity savings are considered.
It should be noted that there has been a long-standing belief in the pottery market that silicon carbide shelves cannot be used in electric kilns due to the risk of electrical shock.
Silicon carbide is an electrical conductor; however, the electrical resistance of advanced NSiC shelves depends on several variables, making the likelihood of an electrical shock minimal. As with any type of powered equipment, observing common sense rules, precautions and maintenance recommendations will eliminate potential hazards. For instance, advanced NSiC shelves should not be used in kilns that are in poor repair with unpinned elements protruding out of their grooves, and an operator should never reach into an electric kiln unless the power is turned off.
View ADVANCER® CN-703 Technical Bulletin for complete information.
Storing and Drying Requirements for ADVANCER® Kiln Shelves
ADVANCER® Kiln Shelves (silicon nitride-bonded silicon carbide) are refractory components and should be stored in a dry, enclosed area.
ADVANCER® refractory components exposed to prolonged moisture penetration may result in catastrophic failure (i.e., steam explosion) during any rapid heat-up process of the kiln. Accordingly, DO NOT expose ADVANCER® refractory components to any prolonged moisture source including rain, snow, condensation, etc.
The application of kiln washes and coatings on ADVANCER® refractory components is an acceptable practice and is not considered a source of prolonged moisture.
If any ADVANCER® refractory components are exposed to prolonged moisture, the product must be completely dried before it is used at temperatures exceeding 100ºC. As a general guideline for the drying of ADVANCER® refractory components, the product must be held slightly above the boiling point of water for a sufficient length of time to expel any moisture and as much steam as possible. The following is a recommended drying cycle for ADVANCER® refractory components exposed to prolonged moisture.
Recommended Dry Out Procedure
- Heat from ambient to 99ºC at a rate of 28ºC/hour.
- Slow heating rate to 14ºC/hour to 110ºC.
- Hold at 110ºC for 12 hours ensuring that the entire load has reached the soak temperature before the timing of the soak has begun.
- Raise temperature to 177-260ºC at a rate of 56ºC/hour.
- Hold soak temperature for 16 hours ensuring that the entire load has reached the soak temperature before the timing of the soak has begun.
- Cool naturally/slowly by turning off the heating source.
ADDITIONAL WARNING – To prevent the hazard of electric shock from any source within an electric kiln, ADVANCER® kiln shelves should not come into direct contact with electrical heating elements.
