Kiln shelves provide the flat surfaces necessary for supporting kiln ware, and they must remain clean and smooth to avoid glaze adhesion. Shelf wash should be applied regularly as this is the best way to do this.
Shelves may be constructed using cordierite, high alumina or nitride-bonded silicon carbide materials; each type has their own set of advantages and disadvantages.
our thin, light kiln shelves are an excellent choice for electric kilns up to cone 11. Their low thermal mass and reduced potential warpage make stacking much simpler in top loaders; plus their flatness ensures more space is left available for large platters or pottery pieces.
our kiln shelves are designed to be both strong and durable, as well as resistant to oxidation, which allows you to store them for extended periods without worry that they’ll crack under prolonged moisture exposure or break apart entirely. Still, using a moisture reduction program when storing silicon carbide kiln shelves would be wise.
our kiln shelves feature low porosity, making water penetration slow; once it does reach their interior though, it may prove hard to expel from their pores. Therefore, using a temperature-controlled, slow moisture removal schedule can ensure your shelf is dry before firing again.
our kiln shelves feature nitride-bonded materials that make them extremely resistant to corrosion by chemicals typically found in kilns such as acids and alkalis, maintaining stable structures within their firing cycles and remaining corrosion-proof throughout their firing cycles. This also ensures they remain intact throughout firing cycles for greater peace of mind for users.
Nitride-bonded kiln shelves provide another advantage when firing ceramic glazes: no additional kiln wash is necessary since any glaze drippings won’t adhere to their surface like they might on oxide-bonded or high alumina shelves.
Conventional
Conventional ram pressed silicon carbide shelves have long been utilized as workhorses in top loading gas, wood, soda and multi-fuel kilns, providing excellent performance under demanding firing conditions such as cone 9-11 in natural gas kilns as well as wood fire ones with salt or soda firing systems. They are particularly suitable for Raku firing processes due to their resistance against direct flame impingement early in the firing process; additionally they don’t sag and are easy to keep clean with just damp sponge.
These conventional kiln shelves feature low porosity for safe use with all types of glazes and clay bodies, without needing protective coating like cordierite requires. While you aren’t required to protect the surface with kiln wash like cordierite requires, it may still be beneficial in protecting unexpected glaze drips or ash sticking to it as it dries – depending on thickness options (from very fine cream to almost powder), select one that best meets your needs!
Try our lightweight kiln shelves made of an advanced Nitride Bonded Silicon Carbide composition which is thinner, lighter and much stronger than standard cordierite shelves. They measure approximately half as thick as traditional 1″ thick shelves but won’t sag or require rotating for the whole firing period – great for all temperatures or kiln types including glassware or stoneware production! They may cost slightly more than conventional cordierite but far cheaper than high alumina models and last a long time too – great options suitable for firing glassware or stoneware production!
Lo-Mass kiln furniture systems as a cost-cutting measure to lower furniture expenses in your kiln, with fitted outlines designed to minimize refractory-ware contact area and costs, thus cutting expenses for furniture significantly. They’re available in multiple sizes and shapes from light weight half rounds up to super light shelves which fit three shelves in typical top loader electric kilns.
Nitride-Bonded
Nitride Bonded Silicon Carbide (NB SiC) is an innovative ceramic material produced through reacting silicon carbide grains with nitrogen to form bonded nitride phase particles, known as “nitridation”, that are then bound together. This process makes NB SiC highly formable while at the same time offering exceptional wear resistance, thermal shock resistance and chemical stability – characteristics it shares with many metal alloys.
NB SiC comes in many standard and custom sizes, shapes and geometries to meet any application need. Manufactured with tight tolerances for manufacturing purposes and designed to withstand high loads and impacts without stretching or bending of its shelf structure, NB SiC can be found in gas, soda and electric kilns.
Nitride-bonded silicon carbide also stands up well against soil’s abrading action, thereby significantly reducing wear. Furthermore, it prevents brittle cracking – another key consideration in tribological applications – though its resistance decreases with grain size increase.
Nitride-bonded NB SiC shows significantly better abrasion resistance in light and medium soil conditions than steels and padding weld commonly employed for metal-mineral tribology pairs, especially against steels or alumina refractory materials; however, its performance falls short when exposed to heavy soil conditions.
nitride-bonded silicon carbide bricks can be found in numerous process furnaces and kilns, from aluminium melting pot sidewalls and lower stacks of blast furnaces, to furniture for kilns themselves. Their excellent stability, mechanical strength, and temperature strengths rival that of oxide-bonded refractories for use.
Nitride-bonded silicon carbide kiln shelves offers superior abrasion resistance than its oxide-bonded counterpart, as well as greater thermal shock and oxidation resistance. Furthermore, these refractories are an ideal choice for use with nonferrous metals such as aluminium and titanium which may otherwise be difficult to reach with traditional oxide-bonded refractories. Furthermore, it boasts superior hot strength making NB SiC ideal for environments characterized by extreme temperatures or rapid changes.
Other
Others kiln shelf materials may help you achieve the results you seek in your firings, particularly their ability to dissipate heat quickly and efficiently – especially important if your kiln experiences repeated thermal shocks. Your choice will depend on both its maximum operating temperature as well as size and weight capacity considerations.
When searching for new kiln shelves, try selecting those with low porosity levels; this will help prevent glaze run-off and sagging of your shelves. Cordierite shelves are excellent candidates in this regard due to their hollow core similar to cardboard. They can withstand higher temperatures than conventional alumina shelves for even wider firing applications.
Your choice of kiln shelf depends on how often and at what temperatures your kiln is fired; this will have an impact on its lifespan. For frequent high temperature firings, high alumina shelves offer lower porosity than cordierite while having higher heat tolerance than standard alumina shelves.
No matter which shelf material you choose, regular cleaning of kiln shelves and furniture is crucial in order to avoid build-up of kiln wash residue and other residues that could hinder its performance and shorten its life span. When cleaning, use either a silicon carbide scraper (rubbing brick) or angle grinder in an extraction booth equipped with protective PPE such as dust masks or overalls for best results.
engineers can assist in designing a complete kiln furniture system for your specific kiln that provides optimal performance and automation. Engineered components may include shelf setters, support posts & stringer beams and structural tie systems; reach out today and let our team begin your custom furniture project!