What is Fused and slumped glass art

Slumped glass art or fusing is the joining together of pieces of glass at high temperature. This process is usually done in a Kiln with temperature ranges between 700°C and 820°C. 

Fusing is the technique of joining two or more pieces of glass by heat in a kiln. 

While slumped (or draped) glass is placed over a mold and heated until it slumps into the designated shape. Frequently, the glass being slumped has design elements already fused to it.

There are many different glass fusing techniques. So, fused / slumped glass art can be any number of things. They vary from slumped bowls and platters, to printed imagery or intrigued forms and shapes on a glass art piece to anything else the mind can conceive and make.

Slumped glass art is a trade learnt over many years. Every glass artist would have a story to tell about how many trials and errors there were along the way. 

What is Glass made of?

Glass is made from liquid sand...

Glass is made from silicon, which is the second most common element in Earth's crust. Actually, silicon is not found in its pure elemental form in nature but rather in various chemical compounds. The most common of which is silicon dioxide, also known as silica. Most people are familiar with silica, because it is one of the primary materials found in sand. You can make glass by heating ordinary sand (as mentioned mostly made of silicon dioxide), until it melts and turns into a liquid. You won't find that happening on your local beach, because sand only melts at the incredibly high temperature of 1700°C.

Fused Glass Art process

Most contemporary fusing and slumping methods involve stacking, or layering thin sheets of glass. Different coloured glass is used to create patterns or simple images. The stack is then placed inside the kiln and then heated through a series of ramps (rapid heating) and soaks (holding the temperature at a specific point), until the separate pieces begin to bond together. The longer the kiln is held at the maximum temperature, the more thoroughly the stack will fuse. 

Once the desired effect has been achieved, the kiln temperature will be brought down quickly through the temperature range of 815°C to 573°C. The glass is then allowed to cool slowly over a specified time, soaking at specified temperature ranges, which are essential to the annealing process. This prevents uneven cooling and breakage and produces a strong finished product.

These temperatures are not hard and fast rules. Depending on the kiln, the size of the project, the number of layers, the desired finished look and even the brand of glass, ramp and soak temperatures times may vary. The cooling takes place normally for a period of 10–12 hours in 3 stages.

With over 25 years of experience and experimenting (which also meant disposing of art pieces that didn’t achieve the expected outcome!), our talented Artist Lisa De Boer has mastered the art of fusing and slumping glass. She has mastered to bring the maximum potential of beauty of glass in every piece to the surface.

Kiln - where the glass fusing happens

A Kiln is a thermally insulated chamber, a type of oven, which produces temperatures sufficient to complete processes such as hardening, drying, or chemical changes.

Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks and also to fuse and slump glass.

Gold coast glass art studio.

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We hope you enjoyed this introduction to the Glass Art World. To learn more about Slumped Glass Art and to gaze at our beautiful handmade artwork, come and visit our online gallery.

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