Slumped glass, most commonly known as “cast glass” because it shares similarities with glass casting process, is in actuality a thermoformed fused glass. Textures, patterns and custom designs are kiln-formed through heating at 1,099–1,251 °F, and then "slumping" the glass panels onto or over a mold.
Firing at a slightly higher range of temperatures (1,251–1,350 °F) is considered "tack fusing".
Glass that has been fired at a range of high temperatures from 1,350-1,501 °F is called fused glass, also known as a "full fuse".
All of these techniques can be applied to one glass work in separate firings to add depth, relief and shape.
To produce a custom piece of slumped glass, the glass is cut to dimensions that approximate the shape of the mold and then placed on top of it before the kiln is heated.
The kiln temperature typically starts to climb at quite a rapid rate until the glass is in a flexible "orange state", at which point gravity will allow the glass to slump into the mold (hence the name "slumped glass"). The peak temperature is then held constant for what is known as the "soak". The kiln is then allowed to cool slowly so that the finished piece can anneal before it is removed from the kiln.
When more than one color of glass are used in the same piece, they must have the same CoE (Coefficient of Thermal Expansion) to prevent fractures caused by the glass shrinking at differing rates. Use of proper materials and setup allows cooling to remain uniform, and ensures that no tension builds up as the slumped glass cools.
All of our ceramic molds for shaping glass are made in house, and our textures and patterns are Gomolka Design originals. We specialize in custom slumped glass designs, created by us or by others, to fit your needs and specifications. By blending creativity and functionality, we can provide architects, interior designers, homeowners and contractors something truly unique and perfect for their space and vision.
Cast/Slumped glass is suitable for both commercial and residential use, and can be used in both interior and exterior applications. Custom glass panels are often combined with stainless steel for a sleek, modern look.
Popular applications include but are not limited to: doors, skylights, partitions, divider walls, flooring, countertops and bar tops, backsplash, glass tiles, lighting, shower and bath enclosures, signage, cabinet glass inserts, stair treads, railings, table tops and furniture.
Our Permacoat™ can be applied to any cast/slumped glass.
For more information please contact one of our trained specialists.