Kiln Guide

Twelve glass fusing kilns ranked by chamber size, voltage, controller and price, plus the 120V vs 240V rule, fusing temperatures by technique, and which controller to pick.

Bullseye (COE 90) and System 96 are the two big fusing systems. Both are excellent; the key is committing to one. Here's how they compare and how to choose.

COE 90 and 96 are the two main fusing systems. Never mix them, and know that 96 matures a touch lower. Here's what COE means and how the two fire differently.

Devit is the cloudy haze on fused glass, caused by surface crystals. It's almost fully preventable: clean glass and the right ramp through the danger zone. Here's how.

Fusing schedules look intimidating but they're all built from the same stages. Here's what ramp, process soak, anneal, and cool each do, and how to read or build one.

Glass frit comes in coarse, medium, fine, and powder — each behaving differently in the kiln. Learn how each size melts, how to use frit in molds for pate de verre, and the COE compatibility rules that apply to frit just as much as sheet glass.

Mixing COE 90 and COE 96 glass will eventually crack your work — sometimes days later. Learn what coefficient of thermal expansion means, why compatibility matters in fusing, and how to keep your glass system clean and consistent.

Fire polish smooths surfaces, tack fuse preserves edge definition, full fuse flows everything flat. Learn what each glass fusing temperature range produces, how to control the outcome, and why a well-calibrated kiln is the key variable.

Glass slumping uses gravity and heat to shape flat glass over a mold. Learn the difference between slumping and draping, why even kiln heat matters, how to prepare molds, and a complete firing schedule for consistent bowl results.