Ceramic Coating for Kilns

Ceramic Coating for Kilns: Protect Your Kiln, Cut Firing Costs, Improve Results

Kiln linings take a beating. Every firing cycle stresses the refractory with thermal expansion and contraction. Glaze drips eat into shelves. Kiln wash flakes off and contaminates work. In industrial kilns, chemical vapors and particulate attack the lining from the inside while heat pushes through the walls.

ITC 100HT is a ceramic coating that addresses all of these problems at once. Rated to 5000°F (2760°C), it bonds permanently to kiln brick, castable, ceramic fiber, and kiln shelves — creating a hard, high-emissivity surface that reflects heat back into the kiln chamber, protects refractory from degradation, and eliminates the need for traditional kiln wash.

What ITC 100HT Does for Your Kiln

Cuts Firing Costs 20–30%

ITC 100HT has an emissivity above 0.95 — one of the highest of any commercially available refractory coating. In practical terms, this means the coated kiln surface radiates heat back into the chamber instead of absorbing it into the refractory wall. Kiln operators consistently report reaching target temperature faster and using 20–30% less fuel or electricity per firing. For studios firing multiple times per week, the coating typically pays for itself within the first month.

Replaces Kiln Wash — Permanently

Traditional kiln wash is a maintenance headache. It flakes, cracks, and needs reapplication before every few firings. Flakes fall onto work and cause defects. ITC 100HT eliminates this cycle entirely. Once applied and fired, it creates a smooth, non-stick surface that glaze drips bead up on and pop off cleanly. No more scraping shelves, no more wash flakes in your glazes, no more reapplication.

Extends Kiln Lining and Shelf Life

The coating seals the refractory surface against chemical vapor attack, glaze contamination, and the micro-cracking that accumulates over hundreds of thermal cycles. Kiln shelves last significantly longer when coated — many users report shelves lasting years instead of months. Kiln walls and arch brick stay structurally sound longer because the coating prevents the surface deterioration that leads to spalling.

More Even Firing, Better Results

The high-emissivity surface distributes radiant heat more uniformly throughout the kiln chamber. Hot spots near elements or burners are reduced. Cold spots in corners and near the door are warmed. The result is more consistent glazes, fewer kiln casualties, and less need to rotate or carefully position work to compensate for uneven heat distribution.

Kiln Types and Applications

Pottery and Ceramic Art Kilns

Electric and gas kilns used for stoneware, porcelain, and earthenware benefit immediately from ITC 100HT. The coating is applied to kiln walls, ceiling, floor, and shelves. Potters report more consistent cone readings across the kiln, shorter firing times, and the elimination of kiln wash maintenance. The coating is safe for all firing atmospheres — oxidation and reduction.

Glass Kilns and Fusing Kilns

Glass fusing, slumping, and casting kilns benefit from the coating's non-stick properties and heat uniformity. The smooth coated surface prevents glass from bonding to kiln furniture, and the improved heat distribution reduces the thermal gradients that cause stress fractures in glass work.

Industrial Tunnel and Shuttle Kilns

High-volume ceramic production kilns — tunnel kilns, shuttle kilns, and roller hearth kilns — see the biggest return on investment from ITC 100HT. The fuel savings at industrial scale are substantial, and the extended refractory life means fewer production-halting relines. The coating is particularly valuable in tunnel kilns where the firing zone refractory sees continuous high-temperature exposure.

Brick and Pipe Kilns

Kilns firing structural clay products, brick, and pipe operate at temperatures and cycle frequencies that wear refractory quickly. ITC 100HT protects the hot face of the lining and improves thermal efficiency in these high-duty-cycle applications.

Raku Kilns

Raku firing is among the most thermally violent processes a kiln can endure — rapid heat-up to cone 06–1 followed by opening the kiln at temperature. This extreme thermal shock destroys unprotected refractory and ceramic fiber quickly. ITC 100HT significantly extends the life of raku kiln linings by hardening the surface of ceramic fiber blanket and sealing it against the thermal shock damage that causes fiber to deteriorate and become airborne.

How to Apply ITC 100HT to a Kiln

Application is simple enough that most kiln owners do it themselves. No special tools or skills required.

What you need: ITC 100HT (one quart covers a small studio kiln; one gallon covers most mid-size kilns), a brush or foam roller, and optionally a spray bottle for thinning. The coating is water-based and cleans up with water.

Surface prep: Clean the kiln interior of loose debris, old kiln wash, and any glaze contamination. A stiff brush or vacuum works well. The surface should be dry.

Application: Stir the ITC 100HT thoroughly. Apply a thin, even first coat with a brush or roller. Allow to dry (usually 2–4 hours at room temperature). Apply a second coat. For kiln shelves, coat both sides and all edges.

First firing: Fire the kiln to its normal operating temperature. The coating will cure completely during this first firing, permanently bonding to the refractory surface. You may notice a slight odor during the initial cure — this is normal and occurs only on the first firing.

Ongoing maintenance: Inspect the coating every few dozen firings. Touch up any areas where mechanical damage (bumped shelves, dropped pots) has chipped the coating. In normal use, the coating lasts hundreds of firings before needing any maintenance.

ITC 100HT vs. Traditional Kiln Wash

Many kiln operators discover ITC 100HT when searching for a better kiln wash. Here's how they compare:

Adhesion: Kiln wash sits loosely on the shelf surface and flakes with thermal cycling. ITC 100HT bonds permanently to the refractory and does not flake.

Maintenance: Kiln wash requires scraping and reapplication every few firings. ITC 100HT lasts hundreds of firings with no maintenance in typical studio use.

Glaze release: Both prevent glaze from bonding to shelves, but ITC 100HT creates a smoother surface that releases glaze drips more cleanly — no more grinding off stuck drips.

Shelf protection: Kiln wash only protects the top surface. ITC 100HT protects the shelf from thermal shock and chemical attack throughout its thickness when coated on all surfaces.

Energy savings: Kiln wash provides no thermal benefit. ITC 100HT reduces firing costs 20–30% through its high-emissivity surface.

Cost: ITC 100HT costs more upfront than a bag of kiln wash. But factor in the labor savings from eliminating wash maintenance, the longer shelf life, and the 20–30% reduction in firing costs, and it's less expensive over the life of the kiln.

ITC 100HT vs. Other High-Temperature Coatings

If you've looked at "high-temperature" coatings marketed for kilns, be aware that most are rated to only 1200°F–2000°F. These are automotive-grade coatings repurposed for kiln marketing. They will burn off, discolor, or fail in any kiln operating above cone 06.

ITC 100HT is rated to 5000°F — well above the operating temperature of any kiln in ceramics, glass, or industrial service. It was formulated for refractory environments, not adapted from automotive applications. For a deeper comparison of temperature ratings and what they mean, see our guide to high-temperature ceramic coatings.

Frequently Asked Questions

Can I use ITC 100HT in an electric kiln?

Yes. ITC 100HT is used in both gas and electric kilns. In electric kilns, apply the coating to the brick walls, floor, ceiling, and shelves — but not directly on the heating elements themselves. The coating improves heat distribution by reflecting radiant energy from the coated surfaces, which benefits electric kilns just as much as gas kilns.

Is ITC 100HT food-safe for pottery?

ITC 100HT is applied to kiln surfaces and shelves, not to the pottery itself. It does not come into contact with food. The coating is an inorganic ceramic material that is fully vitrified after firing and does not off-gas or transfer to ware. Your glazes and clay bodies determine the food safety of your pottery — the kiln coating has no effect on this.

How much ITC 100HT do I need for my kiln?

For a typical studio kiln (7–10 cubic feet), one quart is usually sufficient for two coats on the walls and ceiling. If you're also coating shelves, a half-gallon or gallon is more appropriate. For larger kilns or industrial installations, contact us with your kiln dimensions and we'll calculate the right quantity.

Will ITC 100HT change the color of my kiln atmosphere?

No. ITC 100HT is chemically inert at kiln operating temperatures. It does not affect kiln atmosphere, firing color, or glaze chemistry. You can fire oxidation or reduction as you normally would.

Can I coat kiln posts and stilts too?

Yes. Coating kiln furniture — posts, stilts, and setters — extends their life and makes them easier to clean. Apply two coats to all surfaces.

Get Started

Whether you're a studio potter looking to eliminate kiln wash headaches or an industrial kiln operator looking to cut fuel costs and extend reline intervals, ITC 100HT is the solution. Tell us about your kiln and we'll recommend the right product and quantity.

Call: 325-223-1882
Email: info@itccoatings.com
Online: itccoatings.com