Our Nitride-Bonded Silicon Carbide Shelves are very thin (as thin as 0.394-inches thick), light-weight, and contain low thermal mass. This means giant savings on your back. That could pay for this investment right away. It also means that your kiln has more room for pottery rather than for the kiln shelves.
Nitride-bonded shelves are much stronger than ordinary silicon carbide shelves and they are much, much stronger than high alumina or other cordierite shelves.
Nitride-bonded shelves are highly resistant to warping. They are rated for temperatures much higher than regular silicon carbide shelves. And their strength lends them to having a much longer working life than other kiln shelves.
The larger shelves have expansion joints, which enhance their long life. The expansion joints relieve stress on the shelf during the expansion and contraction that takes place during firing and helps protect against cracking. Even without the expansion joints, Nitride Bonded Silicon Carbide Shelves outlast most other types of kiln shelves, but this improves them further.
Important Warnings (read before using your new shelves)
WARNING! All silicon carbide shelves conduct electricity. When using these shelves in an electric kiln, avoid a serious electrical shock by following these guidelines:
- WARNING! Never insert or remove the shelves into an electric kiln when the kiln is in the ON position. All it takes is the shelf touching an element to cause an electrical shock.
- WARNING! Never load, unload or put your hands in the kiln when it is in the ON position.
- WARNING! Always repair loose elements so that they don't hang out of their slots allowing them to touch the silicon carbide shelves creating a "shocking environment!"
- WARNING! Although we are not aware of specific deteriorating, fracturing or exploding problems with our nitride bonded shelves, some other types of silicon carbide shelves have been known to explode when fired wet. To avoid such potential problems, don't allow your shelves to get wet!
Important Owner Information (read before using your new shelves)
Clean your new shelves thoroughly upon receiving them. Silicon carbide has a tendency to abrade slightly during shipping causing a fine, silicon carbide grit to form on the surface, edges and in the expansion slits (not present on all shelves). Wipe off the shelves and slide a thin blade though the expansion slits to remove any particles and avoid "grit contamination" during firing.
Some shelf sizes include expansion slits that help reduce breakage from thermal shock.
The film of "white powder" on your shelves emerged from the silicon carbide material during the refractory firing. It will have no negative effect on your use of the shelves.
During your first firing, you may experience a dark blotching or discoloration on both the surface of the shelves and the ware with which they come in contact. This results from a lack of oxygen in the firing environment. Conducting a pre-firing (without ware) in a full oxidation atmosphere can significantly reduce this discoloration.
Just as with other silicon carbide shelves, your new nitride bonded shelves may be somewhat more prone to crack under severe thermal abuse than typical clay shelves. If you are new to silicon carbide shelves, or if your firings include exceptionally rapid cool-down or other harsh treatment, you may want to check with your dealer to determine steps you might take to prevent potential damage.
Posting your shelves: Because of the lightweight, thin design of your nitride-bonded shelves, using three posts is not only the most efficient but also the most effective way to load your kiln. Three posts versus four helps negate any unevenness in the kilns floor and, more likely, in the posts themselves. It doesn't matter how strong the shelf, four uneven posts under one shelf will most surely result in a broken shelf – sooner or later!
Note: It is difficult to make Nitride Bonded Kiln Shelves that are 100% flat. Our Affordable Nitride Bonded Silicon Carbide Kiln Shelves are close and they are extremely resistant to further warping. Our standard is that they not be off by more than one half of one percent from the furthest length of the shelf (diagonal on rectangular shelves).
