Fused tile with devit, re-fired with clear powder

Use Bullseye Clear powder to fix surface flaws
The growth of crystals on glass, aka devitrification, aka devit, is not that common or easy to create. But if devit does appear on your fired glass, there are several ways to remove it. One simple way, for glass that's flat, is to sift a very thin layer of Clear powder (2 grains thick) over the entire piece until the surface appears white. Then re-fire at 1425°-1450°F (774°-788°C) for about ten minutes, depending on the kiln and thickness of the glass. The resulting piece, like our tile on the right, will have a clean appearance. This method is similar to working with overglazes, but Clear powder has advantages: it contains no lead + it fires quickly + a very small amount will get the job done.

View Bullseye Clear Transparent Powder (001101-0008)

To learn about preventing devitrification:
Download TechNotes 4: Heat & Glass
Download Glass Cleaning Basics

Bullseye Glass Co. is a leader in promoting glass art worldwide through quality production of colored glass for art and architecture, research and education, and the presentation of innovative glass art in its Portland gallery.