Fusing Glass

Introduction

Let's face it, I'm obsessed with glass. I've made stained glass for years, and I built miniature studio in my garage so I can make torch-worked sculptors.

Fusing, and slumping is one of the few glass art forms I haven't yet tried.

Having no previous experience in fusing, I decided to take a class at the Bay Area Glass Institute (BAGI):

What is Glass Fusing?

Fusing is the process of heating multiple pieces of glass in a kiln to form one unified piece. Heating the glass just enough to join, but while still retaining the original shape of the individual pieces is called a tack fuse. Heating the glass enough to form one seamless piece is called a full fuse

What is Glass Slumping?

Slumping describes the processing of reshaping a piece of glass by heating it, and allowing it to fall into a mold (form).

Instructor

My instructor, Janett, has an amazing knowledge of not only glass fusing, but also torch working, glass blowing, and stained glass:

Tools

Here's the tools of the trade:

Bullseye glass

Kiln

Glass cutter

Fusing glue

Not all glass is appropriate for fusing. Glasses which expand, and contract at different rates will indeed fuse, but then crack as they cool. Bulseye glass is the most popular as it comes in a wide variety of colors, and styles.

Kilns are basically big ovens which can reach about 1600^o

Glass cutters are used to create scores, and direct glass to crack along certain lines.

Fusing glue hold the glass in place before it is fired.

Kiln shelf

Kiln wash

Applying kiln wash

Fusing is typically done on a large flat unfinished ceramic kiln shelf.

Kiln wash is basically glass Teflon. It keeps the glass from sticking to the shelf.

First Project

Glass fusing is deceptively simple: Cut out pieces of glass, arrange them, and pop them into the kiln. Here's my first project:

Red circle of glass	Cut-up circle of glass	Into the kiln
Fused circle

But there are any number of things that can go wrong. Molten glass flows -- sometimes in unpredictable ways. Fire too long, and the glass will spread out, and then contracts back leaving uneven borders. Fire too short, and you'll get lumpy glass. Some glasses melt faster, and spread out when fired; others tend to stay put. And many types of glass don't fire true -- i.e. change color when fired. To help out us neophytes, Janett created this pallet of pre- and post-fired glass:

Second Project

Here's my second project. On the bottom is a layer of clear glass. The second layer has red on the edges, stripes of black, and more clear in the center. On top of that is amber squares, and sparkling green stringers (thin rods of glass).

Before fusing

Fused, and slumped

Julie's Projects

Here's a few projects made by my classmate Julie. The piece below is made of three layers of glass, giving it great depth. Some of the squares almost appear to float.



Here's very simple, but elegant design:

Big Tools

One of the cool things about BAGI is their equipment. I grew up with a garage full of lathes, acetylene welder, and drill presses, so I found BAGI's collection of over-sized glass grinders fascinating:

Belt grinder

Bench grinder

Disk grinder

Holiday Sale Items

BAGI is a nonprofit organization, and every year they have a Holiday Sale. Artists donate pieces, and the proceeds go to BAGI. These are amazing. I guess it's always good to have something to work up to ...

Holiday Sale

Holiday Sale

Holiday Sale

Holiday Sale

Conclusion

I've seen a lot of fused glass at art shows -- much of it monumentally bad. From this I assumed any yo-yo could fuse. But it's more complex than I expected. There's a lot of technical gobbly guck: coefficient of expansion, annealing/fusing/tacking temperatures, devitrification. There are four types of clear glaze that melts at different temperatures. There's dozens of types of glass: transparent, opaque, streaky, iridecent, textured, dichroic, two types of black, and 19 types of clear!

But it's not that hard either, and it is great fun.