WHAT IS FUSED GLASS?
Fused glass, also known as warm glass or kiln-formed glass, is made when separate pieces of glass are heated in a kiln until they melt and fuse together into a single piece. Typically, fusing refers to any glass that has been worked in a kiln.
Glass fuses at around 1450 to 1500 degrees Fahrenheit. While there are many techniques to get the glass to react in a way that you want to create a certain effect, there is a large range of temperatures that are used, some up to 1800 degrees and beyond. The behavior of glass when heated is very complex with different things occurring at different temperatures. Working in a kiln requires complex steps to ensure that the outcome is as you desire. It by no means is as simple as turning a kiln on and walking away, projects require a program/schedule to heat and cool at certain rates, as well as holding the glass for extended periods of time at different and precise temperatures.
A very important part of fusing glass is the controlled rate of not only heating, but cooling. The process by which fused glass is cooled at a controlled rate is called annealing. Through the process of annealing, the molecules in the glass are aligned, thereby reducing residual stress and making the fused piece stronger than most drinking glasses.
When fusing two pieces of glass together, it is important that each piece shares the same coefficient of expansion (COE). Glass expands as it is heated, but not all glass expands the same amount. The COE is a measurement of the rate at which a particular piece of glass expands. If two pieces of glass with different COEs are fused, the resulting fused glass piece will crack as it cools. All of my fused glass pieces are made from formulated 96 COE glass.
Slumping or draping are processes used to shape fused glass over or into a mold. Slumping for most pieces on this site is done at around 1200-1240 degrees Fahrenheit.
Standard glass pieces take about 15 to 30 hours in the kiln. Larger/thicker pieces can add days or weeks to complete.
Fused glass, also known as warm glass or kiln-formed glass, is made when separate pieces of glass are heated in a kiln until they melt and fuse together into a single piece. Typically, fusing refers to any glass that has been worked in a kiln.
Glass fuses at around 1450 to 1500 degrees Fahrenheit. While there are many techniques to get the glass to react in a way that you want to create a certain effect, there is a large range of temperatures that are used, some up to 1800 degrees and beyond. The behavior of glass when heated is very complex with different things occurring at different temperatures. Working in a kiln requires complex steps to ensure that the outcome is as you desire. It by no means is as simple as turning a kiln on and walking away, projects require a program/schedule to heat and cool at certain rates, as well as holding the glass for extended periods of time at different and precise temperatures.
A very important part of fusing glass is the controlled rate of not only heating, but cooling. The process by which fused glass is cooled at a controlled rate is called annealing. Through the process of annealing, the molecules in the glass are aligned, thereby reducing residual stress and making the fused piece stronger than most drinking glasses.
When fusing two pieces of glass together, it is important that each piece shares the same coefficient of expansion (COE). Glass expands as it is heated, but not all glass expands the same amount. The COE is a measurement of the rate at which a particular piece of glass expands. If two pieces of glass with different COEs are fused, the resulting fused glass piece will crack as it cools. All of my fused glass pieces are made from formulated 96 COE glass.
Slumping or draping are processes used to shape fused glass over or into a mold. Slumping for most pieces on this site is done at around 1200-1240 degrees Fahrenheit.
Standard glass pieces take about 15 to 30 hours in the kiln. Larger/thicker pieces can add days or weeks to complete.
For more basic information about glass:
https://en.wikipedia.org/wiki/Warm_glass
https://en.wikipedia.org/wiki/Art_glass
https://en.wikipedia.org/wiki/Warm_glass
https://en.wikipedia.org/wiki/Art_glass
While this is not the same glass that is used in art glass, this video is fascinating and shows how "float glass" is made. Float glass is what you see used in windows and other similar applications.
http://www.pilkington.com/en/us/architects/resource-library/float-glass-process-video
http://www.pilkington.com/en/us/architects/resource-library/float-glass-process-video