Kiln Corrosion, is it normal?
Kiln corrosion refers to the chemical and physical degradation of kiln components — especially metal hardware (hinges, screws, control panels, bands), Kiln elements (in electric kilns), Kiln walls and insulation (over time) — due to prolonged exposure to heat, moisture and off-gassing from clay or glazes
Common Sources of Corrosion
Fumes from Glazes
Certain glazes (especially those with boron, salt, or sodium) give off vapors that are highly corrosive. These fumes can erode metal parts and corrode kiln elements, especially in electric kilns.
Moisture & Humidity
Storing a kiln in a damp garage or outdoor shed can accelerate rusting and corrosion. Moisture in the air + heat cycles = metal fatigue and rust over time.
Poor Cleaning Habits
Glaze drips or spills on shelves and kiln bricks release corrosive fumes during firing. Dust and clay residue can also burn off, contributing to corrosion.
How to Minimize Kiln Corrosion
Vent the kiln Install a downdraft or cross-draft vent to remove corrosive gases.
Use a dry, well-ventilated room Avoid humid environments, firing outside or garages without airflow.
Clean kiln shelves and bricks Remove glaze drips, and use kiln wash to protect surfaces.
Wipe down metal parts Occasionally clean external metal components with a dry cloth.
Avoid corrosive glazes Limit use of soda, salt, or heavy boron glazes if firing frequently.
Inspect elements and metal parts Look for signs of rust, pitting, or brittleness and replace as needed.
Accept the Inevitable and Plan for It
Kilns are wear-and-tear tools, not lifetime appliances. Even well-maintained kilns will:
- Need element replacements
- Show rust or wear on hinges, lids, and frames
- Gradually lose insulation efficiency
With smart maintenance and firing habits, you can extend your kiln’s life by years.
