Kiln Support
Paragon HomeKiln ProductsWhere To Buy KilnsKiln SupportAbout ParagonKiln Resellers and Dealers
Search Menu


Why does a gap form on the left and right curved ends of the lid on my oval kiln?

A firebrick lid does not remain flat at high temperatures. The inner lid surface expands more than the outer surface, resulting in what we at the factory call "oil canning." Since the inner lid surface expands more than the outer, the lid bows downward toward the firing chamber. The outer surface becomes very slightly concave, and the inner surface becomes convex. The change in shape is not enough to notice except around the edges of the lid, where you will see a line of light.

The change in shape is more pronounced on the oval kiln than it is on the "round" 10- or 12-sided kilns. The oval lid bows upward about 1/4" from the kiln body on the left and right side. When the lid cools down again, it flattens out. This is nothing to be concerned about.

Paragon Kilns on FacebookParagon Kilns on Twitter Paragon Kilns on YouTube Paragon RSS Feed

Kilns Sold

Get The Adobe Reader


  • Home
  • Privacy Statement
  • Legal Notice
  • Paragon's Green Statement
  • Where To Buy Kilns
  • Resellers
  • About Us
  • Contact Paragon
  • News & Events
  • Support

  • Kiln Technicians
  • Kiln Support
  • Products

  • Bead Kiln
  • Glass Blower's Crucible Furnace
  • Ceramic Kilns
  • China Painting Kilns
  • Enameling Kilns
  • Industrial Furnaces
  • Glass Kilns
  • Lamp Working Kilns
  • Pottery/Ceramic and Glass
  • Pottery Kilns
  • Silver Clay Kilns
  • Wax Burnout Furnaces
  • Heat Treating Furnaces
  • Knife Making Furnaces
  • Custom Furnaces
  • Discontinued Models
  • “Custom and standard Kilns and Industrial Furnaces for ceramics, pottery, heat treating, enameling,
    dentistry, laboratory, and glass fusing.
    Better Designed Kilns from Paragon Industries!"