Kiln Furniture – Kiln Shelves

Kiln Furniture includes the shelves where ceramic ware sits during its firing process in a kiln. Nitrogen-bonded silicon carbide shelves make an excellent choice due to their abrasion-resistance and physical strength, providing optimal conditions for their placement within the kiln.

LO-MASS shelves are 19x stronger and 50% lighter than conventional cordierite shelves while still supporting loads up to Cone 16. With nearly zero porosity, they provide great glaze resistance, lessen kiln wash usage, and reduce thermal mass by having less thermal mass in your kiln.

1. Sturdy

Kiln shelves provide essential support to pottery during firing, sintering and heat treatment processes. Made of cordierite, high alumina or silicon carbide material – in various shapes and sizes – they come in handy during these processes. At IPS we offer both standard silicon carbide shelves as well as those bonded with nitride for increased loading capacities; additionally we can supply props to reduce shelf count needs for specific loads.

One of the key considerations when selecting a kiln shelf material is its ability to accommodate sudden temperature shifts. Silicon carbide’s low thermal expansion coefficient enables it to withstand significant thermal shock without cracking or degrading, making it an excellent material choice in kilns where temperatures frequently vary and requires consistent firing results for energy efficiency.

Silicon carbide’s durability and longevity is another benefit, making it the ideal material for use as a kiln shelf material. Much harder than alumina and capable of withstanding high temperatures without deforming, silicon carbide provides crucial support in terms of stability and warping reduction over time. Furthermore, due to reduced porosity compared to its ceramic counterpart, preventing glaze drips or contaminants from adhering directly onto it and saving valuable time by eliminating regular cleaning tasks using either a diamond rubbing brick or angle grinder.

2. Low Porosity

Silicon carbide makes an excellent material choice for kiln shelves due to its extremely low porosity compared to most other shelf materials, meaning glaze doesn’t seep deeply into its surface and becomes much simpler to remove once your shelf has cooled and been cleaned.

Nitride-bonded silicon carbide ceramics offer outstanding resistance against warping or sagging over time, maintaining a flat surface even under heavy loads in gas and soda firing kilns. Their strength also makes them an economical alternative to cordierite shelves – saving both time and money in hobby, production studio or industrial applications.

Advanced nitride-bonded silicon carbide shelves are 19 times stronger and weigh half or less than conventional 1″ thick cordierite shelves, capable of withstanding temperatures up to 2600degF.

Silicon carbide kiln shelves extend their longevity due to expansion joints built into their design. These joints help relieve strain from expansion and contraction of the kiln as it changes size, as well as protecting against cracking. When used with electric kilns however, power must be disconnected prior to loading or unloading for safety purposes, otherwise there is risk of electrical shocks.

3. Easy to Clean

Long held to be unsafe in electric firing applications is no longer true as the advanced NSiC shelf can be safely utilized in top-loading resistance coil element kilns up to cone 16. NSiC shelves offer far less stacking space and reduced energy costs than their 1-in. cordierite counterparts. Furthermore, 19 times stronger materials offer 19x less weight for more stacking space efficiency.

These kiln shelves are also less susceptible to warpage due to heat differences across their surfaces from stacking and ware placement, especially when fired at higher temperatures such as wood or salt firing. Furthermore, these shelves don’t require shelf wash for glaze drips and ware apart from soda firing where an alumina-based wash may be recommended instead.

As these shelves have lower porosities than traditional cordierite ones, cleaning is much simpler. Glaze runs and kiln wash can be quickly scraped off using steel scrapers or hand rubbing bricks with fluted 20-grit surface (the best hand kiln shelf cleaner available). Heavy grinding should be conducted in an extraction booth with adequate PPE such as overalls and dust mask.

4. Longevity

Silicon carbide shelves are thinner (about 5/16-in) and lighter than their cordierite counterparts, making it easier to stack. This translates to more space within your kiln for stacking purposes as well as decreased handling costs associated with heating. Plus, they remain flat even under heavy loads so no rotation is needed!

Nitride-bonded kiln shelves differ from cordierite by possessing low surface porosity that prevents glaze dripping and makes it easy to scrape away ware from shelves. Furthermore, these shelves resist cracking and warping caused by rapid heating or cooling cycles and can be used up to cone 10 in electric kilns; making them the optimal choice for soda firing due to being less susceptible to cracking from direct soda spray impacts.

As soon as you receive your new nitride-bonded silicon carbide kiln shelves, be sure to thoroughly clean and dry them after receiving them. They may have a thin film of silicon carbide grit from being handled during shipping; this is normal and can be removed by wiping down shelves with damp sponge or wiping blade or by sliding thin blade through expansion slits (not present on all sizes). Thorough drying also helps reduce thermal shock during initial firing cycles for optimum shelf longevity.