Glass articles - Glass Makers and Artists |
Scotland's Glass version 2008 - Shiona Airlie and Frank Andrews |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
AN EXPERIMENTAL GLASS FURNACEDuring the 1969-1970 session at the Edinburgh College of Art it was decided that a small experimental glass tank furnace be built. The design of this furnace was governed by the following considerations; the furnace had to be inexpensive to construct and operate, it had to be quiet and cool to work at and be suitable for a student or artist craftsman, it had to be capable of working without electrical power, it had to be reliable and economical. The concept of a small studio-type furnace was not new, several had been built and are in operation. In 1963-64 the Labino type furnace had been built by Mr. H.K. Littleton at the University of Wisconsin. As can be seen in the illustration and plans of this type of furnace, the basic shape is that of a rectangular tank with an opening at one end and covered with an arched roof or crown. The Labino burner on the 1963 furnace is at the side while on the 1964 furnace it is on the top as shown in the photograph. Both furnaces required forced air and since there was no flue all the exhaust gases and heat were blown out of the front door. This type of furnace was not used for melting batch but was filled with either cullet or glass marbles which allowed for a lower working temperature range but was still rather noisy and hot to work at. The experimental furnace designed and built at the Edinburgh College of Art by Mr. K.G. Wainwright and Mr. J.G. Airlie is a rectangular tank of selimanite brick with an outer covering of refractory insulation bricks. The two venturi burners are introduced through side openings which are angled to the rear diagonal corners of the tank. The crown of the furnace is flat with a flue opening at the front in order to induce a circulatory flame pattern. This flue is lead back across the top of the crown to the stack in order to increase the flame length and increase the tank temperature by radiated heat from the crown. This type of flue ensured the maximum gas combustion within the furnace and reduced the CO2 discharge from the stack to a very low level. The position and size of the flue opening in the crown was discovered to be critical, any alteration in size or positioning of the flue at the lower end distorted the flame pattern and caused a subsequent lowering of temperature in the combustion chamber. The length of the stack at the flue exit also caused a great variation of tank temperature, but as there was a physical limit in the furnace room to the stack height it was not possible to extend or to lead it to the outside of the building; this set a limit to the maximum temperature and efficiency of this particular furnace. By exercising control over the damper at the tap of the stack, the pressure or "draw" on the furnace could be controlled. It was found that the two venturi burners set at ¼ to ½ open were most efficient both in performance and gas consumption, and that both burners fully open did not increase the tank temperature but caused a wastage of fuel due to inefficient combustion. When both burners were being used at normal settings it was found that if one burner was switched off there was a distortion of the flame pattern, that the flue failed to function and that the flame blew back out of the door as in the Labino furnace causing a lowering of temperature and wastage of fuel. A series of tests were run using batch mixes of various types, soda lime, lead flint and soda lime with a low lead content. a suitable batch was found and filled into the furnace and glass of a fairly good quality was made. Several articles were made to test the handling and workability of the metal and it was found to have a viscosity and temperature range suitable to the needs of the student and artist craftsman. The furnace was stripped down and rebuilt in order to check the chemical action of the batch on the bricks. The chemical corrosion on the bricks was found to be of a reasonable level. A thermocouple was fitted in order to check the tank temperature. The rate of temperature rise was recorded from first lighting the furnace to founding and working the metal; gas consumption was also recorded over this period. The test runs on this furnace show that a furnace of this type is a viable proposition for an educational establishment or an artist craftsman to build and operate. It is of a reasonable size, silent in operation with a very high safety factor. It can be switched off for long periods then relighted without harm to the glass or the tank. Gas Board officials who examined the furnace commented on its efficiency and very low CO2 discharge and recommended the installation of a low pressure cut-out switch in the supply line and this was carried out. For the first time a studio type furnace, using venturi burners instead of forced air, has been built which is capable of making glass from the raw materials instead of having to depend on cullet or glass marbles. This innovation in studio glass furnace design could give to the artist in glass the facility and impetus which the electric kiln gave to the studio potter. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Airlie-Wainright Furnace |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Airlie-Wainright Furnace |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ACKNOWLEDGEMENTSI wish to express my thanks to: MR D. COHEN, D.A. (Edin) for information on burners. MR I. NELSON, D.A.(Edin), for information on the Labino and Lyttleton furnaces, and for photographs. MR R. HUGO, D.A.(Edin), for photographs of the Airlie-Wainwright furnace. MRS A. MACDONALD for her help in preparation of this thesis. MR K.G. WAINWRIGHT Master Craftsman, Lecturer in glass making in the Glass Design Department of the Edinburgh College of Art, for his help, encouragement and unfailing enthusiasm in this project. JOHN G. AIRLIE,
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Exhibitions and CommissionsCrystal carvings:Glasgow Museums, Kelvingrove Art Gallery Blown glassSt Mary's Church Dalkeith "Crystal Altar set" Wood Carvings:St Marks Church Portobello "Madonna" |
← John Airlie - Glass Artist and Innovator | Frits Akerboom - Lampwork & Slumped → |
---|
< Previous | Next > |
---|
Joomla template created by Rosswerkz Studios