Glass Bog Series: Glass-Making Techniques

Published 30 August 2022 in Media Blogs

Last week, we introduced our Glass Blog series, beginning with reminding you that this year was dubbed the Year of Glass by the UN – so if you’re interested in all of that goodness, check it out here.

Remember the most amazing materials can sometimes be found right under our noses, or rather in this case beneath our feet. The main ingredient in making glass is sand, more specifically silica sand (quartz sand). But this week we’re going to be looking at the various methods used by artists to create incredible artworks from this material.

And the result of some of these techniques can be seen currently at The Viewing Room Art Gallery with works by Lothar Bottcher, Jason Brits, Kgotso Pati and on 10 September the works of the TUT glass students will be on display with their exhibition titled Next Generation, in celebration of 2022 Year of Glass.

When glass art is created there are 3 basic methods: Hot glass, warm glass and cold glass and within these 3 methods lies various techniques.

Hot glass techniques include, glass blowing, sculpting and casting glass into moulds, this requires glass to be heated to approximately 2000°C to a molten state.

Warm glass makes use of a kiln to fuse glass at a temperature of 1400° to 1600° or to slump glass at a temperature of 1250° to 1400°.

Cold glass techniques are any type of technique or application to cold glass, examples of these are grinding, polishing, etching, or engraving.

A recent addition to the category of art is knitted glass!!!

So, for some brief details about the previously-mentioned techniques:

·         Glass-blowing: using molten glass and blowing air into it with a metal pipe to create bubble shapes then manipulated into some truly extraordinary creations.

·         Flame-working: this technique uses a lamp or torch to melt the glass and then shape it continuously throughout the process as the glass is kept at a workable, malleable, and loose consistency.

·         Glass casting: just as “casting” suggests, this method uses pre-designed and formed moulds that molten glass is then channelled into – left to cool and solidify and you have a glass artwork.

·         Fusing and Kiln-casting: fusing is literally fusing pieces of glass together that melt down and mix into each other. Kiln-casting, again, uses a mould, however, instead of using molten glass and leaving it to cool, solid glass and mould are placed into the kiln to allow the pieces of glass to fuse and form within the mould.

·         Engraving, polishing and cutting: change the shape and surface of the glass without using heat; skill and specific tools are necessary to achieve the desired effect.

·         Knitted glass: this is a multiple-step process in melting the glass, using moulds, and then working the glass into desired patterns and knots while it is heated enough to be malleable, but cool enough to hold its shape (as though wool strings).

·         Broken glass: this is a very popular craft method, resulting in mosaics and embellishments for other pieces and works of glass.

These methods are used singularly and with another, with staining to create colour – as seen in most glass objects and works nowadays and the plentiful windows of, especially, the Gothic Art Era (mid-12th century to the 16th century).

And as 2022 is the international Year of Glass, we should probably mention that in Africa we do have connections to glass works. Such as the Ife-Ife glass production, and the various glass beads made throughout the continent.

Glass needs skill and most often a constant and consistent supply of heat (and electricity) for the furnaces. As mentioned in an earlier [blog] Jason Brits creates and masters in glass art, however, with loadshedding (specifically stage 6), he could not create his glass works. As a result, he turned to drawings again and works with his glass when ESKOM permits.

So, there are limits for glass artists as they need the sources of heat, the specific tools, the space to work and let dry, and store. The process to create one work requires multiple steps, therefore needing multiple sections of space in which to practice these steps.

The upcoming exhibition is showcasing the works of the students of TUT, the young adults wanting to practice what some may consider a dying art form – one that has been here for ages – and making it modern.

- Cassandra Comins

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