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


How do you prevent fused glass from cracking?

Most problems in fusing are caused by rushing the firing. The glass must heat slowly during the critical temperature range of 100 – 500 degrees F.

The second critical temperature range is annealing, which is the cooling range of 950 – 750 degrees F average. Cool the glass slowly in this range so the stress in the glass will have time to dissipate.

If you become impatient after the glass has fused and you crack open the lid of the kiln for a few seconds to peek inside, you may hear a “ping,” which is the sound of glass cracking. Avoid the temptation to open the lid. Wait until the kiln has cooled to room temperature. Some artists schedule their fusing so that it is completed before they go to bed. That way they will be asleep while the glass cools and they won’t be tempted to open the lid.

After each firing, examine the shelf. Recoat if the kiln wash is chipped. When glass sticks to a bare section of the shelf, the glass cracks.

If the cracks appear along the edge lines of glass pieces that are fused together, then the cracking may be due to incompatible glass. This may happen if you fuse different brands of glass.

If the edges of cracks are rounded, then the glass probably cracked as it heated up. If the edges of cracks are sharp, then the glass probably cracked during cooling.

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!"