What is fused glass anyways?
Customers are frequently drawn into my booth at craft shows like moths to flame—flaming color that is! Glass is stunning in the array of hues, textures, and patterns it offers the creative vision. “What kind of stone is this?” they’ll ask…. It’s no stone at all; in fact…it’s really glass.
In the technical sense, glass is an inorganic product of fusion which has been cooled through the glass transition to a rigid condition without crystallizing (see Wikipedia). So, in fact, fused glass re-fuses the glass to make the molecules bind in a new and different way.
Fused glass requires fusible glass…that is, glass that can be heated to extreme temperatures (up to 1500 degrees) and can bond successfully to other layers of glass. I buy sheets of fusible glass based on whatever colors resonate with my creative vision. I choose to use Bullseye glass because of its high quality.
To design my pieces, I cut the sheet glass using a glass cutter, position the layers of glass as desired, affix the layers with glue to keep them in place, and then set the ensemble on the kiln shelf. Once I’ve filled the kiln, I start the kiln’s timer to fire the load.
As the load fires, the kiln heats up to whatever temperature is desired to change the composition of the glass so that it melts and binds with adjacent layers of glass. Typically, the fusing temperature is somewhere over 1400 degrees. Once the target temperature is reached, the kiln soaks the glass for a few minutes at this temperature. The longer glass soaks, the more it gets a melted look about it…hard edges become smooth, rectangles left too long become circles. After soaking, the temperature is decreased by almost half (around 900 degrees) so the glass can anneal. Annealing simply means that the layers of glass adjust their compositional makeup so they more completely fuse together. I imagine the layers of glass as new neighbors…”hey, I think I like you! come closer! stick with me and I’ll show you the ropes!”
Once the temperature in the kiln has returned to normal, the finished fused glass pieces can be removed from the kiln! Voila!
