Fused Mason jar art uses older, colored mason jars for the easy hues they add to the glass art. Glass of any variety, not only in mason jar form, can be melted down at high temperatures and individual broken pieces can fuse together to make necklaces, earrings, piercings, etc. To "full fuse" glass together, a kiln must be able to reach temperatures of 1450 degrees Celsius.
Fusing a Mason Jar
Place the glass you desire to melt in a kiln-safe container or mold.
Heat the kiln slowly, at about 350 degree per hour so that the glass melts and doesn't shatter. The melting point of glass will vary based on the manufacturer.
Heat glass to 900 degrees to create a uniform temperature throughout the glass, where the glass temperature should hold for 15 minutes. Depending on the amount of melt desired, this may be as hot as the user wants the kiln to get. To smooth out sharp edges on a broken mason jar and get the glass to partially fuse, for example.
Heat the kiln to 1250 degrees Celsius at a rate of 700 degrees per hour, after the temperature has reached 900 degrees and no risk of fracturing is likely. At 1250 degrees, the glass will be moldable. Holding the temperature at 1250 degrees for twenty minutes will allow the glass to expel all air bubbles trapped within.
Heat the kiln to 1450 degrees and hold the temperature for roughly 22 minutes, depending on the glass manufacturer.
Cool the glass inside the kiln at a rapid rate to 960 degrees. This temp should hold for 45 minutes. The thicker and bigger the glass, the longer it can take to settle and become uniform.
Cool the glass to 700 degrees.
Turn off the kiln and let it cool overnight.
Many kilns are readily available commercially.
Glass cuts. Hot burns. Wear protective equipment.