David Salt and Richard Whiteley

In December 2006 the Glass Workshop in Canberra received from the Australian National University a Major Equipment Grant for almost $130,000AUD to build the next generation of glass facility. The facility, currently under construction, will comprise a sets of large kilns that will be configured for multi point annealing, a new hot glass furnace - designed by renowned furnace specialist Fred Metz, pot furnace and pick up kilns. At the heart of the research the team in Canberra aim to provide practical information on multi point annealing for artists working in glass. The facility also aims to allow students in Canberra to push the limits of the material and develop new creative works in glass.

Background One of the most challenging aspects of creating innovative glass art is dealing with the tension that can build up in the glass as it cools. Not only can this tension warp the shape of the form being created but, because glass is such a brittle material, it can lead to the glass cracking when subjected to a bump or a small temperature change.

To ensure this doesn’t happen all glass products produced from a molten state need to go through an annealing process while cooling back to room temperature. Annealing involves stabilizing the temperature at a specific point so internal stresses can ease. Then the glass must maintain precise cooling rates back to room temperature to produce a work with low internal tension.

Annealing larger and more complicated shapes in glass is a highly technical business in industry and research. Sophisticated industrial annealing approaches use targeted multi-point readings in the kilns to maintain a tight corridor of maximum/minimum thermal parameters for precise annealing for glass of larger size or complexity in shape. For example, the Mirror Lab facility at the University of Arizona, USA produces the world’s largest, lightweight land-based reflecting telescope mirrors. It uses a kiln some 10 meters in diameter to anneal the glass for its large mirror blanks, at close to 20,000 kg they are in themselves the world’s largest objects of cast glass. This kiln has over 200 thermocouples (temperature sensors) to allow the precise control of the annealing process. It was after seeing this facility the head of the Glass Workshop, Richard Whiteley, got the idea to translate this approach for artists.

In stark contrast, the kilns used by glass artists have only a single thermocouple and the annealing profile can often be unstable due to temperature variations in the kiln at any one time, this has been a limiting factor to scale and artistic innovation. The Glass Workshop is embarking on a project to translate the complicated industrial approach so individual studio based artists can improve their efficiency in annealing and their success rate. The aim is to be able to provide artists with the tools to achieve accurate thermal profile information, and importantly, be able to control this without a cost prohibitive infrastructure.

The Project Developing a multi-point annealing facility for artists will take the guesswork out of the annealing process by providing accurate temperature readings of the kiln environment and allow the annealing computer to make necessary adjustments for the cooling profile of the glass.

The advantage is that complex innovative and larger scale creative works can be more easily and reliably produced at a savings of time and money. The Glass Workshop is proposing to build a set of four large scale kilns featuring the facility of multipoint annealing support and zone temperature control so that heat of individual kiln chambers can be controlled separately as required.

A better understanding of thermal dynamics within kilns will give researchers real information as opposed to the blunt instrument of a single point annealing. Through the sensitivity of equipment, these kilns will allow senior students and staff the ability to cross over between forming processes with much more certainty and success.

Additional equipment, such as the new furnace and related equipment will provide a better quality base material allowing more reliability for each researcher. By providing better quality glass from the start the team will overcome many of the problems with cords, stones etc. To assist in the project Dr David Ellis from Earth and Marine Sciences ANU has been offering advice and support with approaches to setting up the technical side of the research. The Glass department at the Monash University in Melbourne will also send staff and students to Canberra to assist explore new works. The head of the Glass workshop at ANU and principal researcher Richard Whiteley says “We have established a excellent reputation for our artistic outcomes. Additionally, many of our senior students have a strong technical research component as part of their practice. We have identified this as an area that needs more collective research to assist the whole sector move forward.”