Newsletter

June '01

Matrimandir's glass inner skin

For many months research has been ongoing in Matrimandir's "inner skin workshop" on site, to identify and solve the problems of providing a glass cladding which will line the sphere of the Matrimandir from the inside. The manufacture of the big peach-coloured triangular panels - 800 of them, covering 3,000 square metres in total - will be needed to complete the work.
In order to give our viewers some idea of what is involved, we post here a progress report, even though it is not really a regular 'work update'.

Experimentation in the glass workshop

Large triangular glass panels

A large kiln, whose internal dimensions are 4 x 3 mtr x 2 mtr high, was built in 1999 for the purpose of fusing colour onto the surface of 8 mm thick float-glass panels. After being laminated to a second sheet of clear glass for reasons of safety, these panels will be used for the inner skin of Matrimandir. Some 800 panels are required, each triangular in shape and roughly measuring 3 mtr at the base and 2.4 mtr high. (Even though the height of each triangle is the same, the shapes differ considerably.)

4 x 3.6 mtr silk-screen frame

The 4 x 3.6 mtr silk-screen frame (largest in the world?)

The colour being used is an oil emulsion containing a mixture of orange and yellow cadmium and other oxides. The emulsion is passed through a homogeniser to produce a very fine paste suitable for silk-screen application.
Before the method of using a silk-screen was selected, other methods of applying the colour were tried, such as spraying. This tended, however, to give a spotty surface and excess evaporation, so was discontinued. Once small-scale silk-screen tests proved successful, a full-scale approach was adopted. For this purpose a very large silk-screen frame measuring 4 x 3.6 mtr was imported from Germany, such a large screen being unavailable in India.
This silk-screen frame is mounted horizontally just above the surface of the glass, and a special table with a movable rubber applicator was built to accommodate it.

Work of great precision

Moment of precision: as the upper frame is evenly moved over the glass beneath the silkscreen, the paint is squeezed down through the screen onto the glass.

After the silkscreen procedure

Once the colour has been applied, the glass triangle is placed on a trolley and wheeled into the oven for fusing. It was found that the evenness of the layer of pigment was as important as the firing itself in yielding the precise colour.

The glass panel on the way to the kjiln

Another particular problem has been how to clean the silk-screen after use. Given the size of the frame, the initial cleaning method involved standing in front of the vertically positioned screen and using turpentine or NC thinner to remove the residue of orange paste. Subsequently, we have found a simpler method which allows for the frame to remain in a vertical position while a long-handled brush is used to clean the surface using kerosene. The kerosene can be recycled since it collects in a catchment under the frame; once the residue settles and separates, it can be siphoned off and used again.

Lamination

Before the coloured glass produced in the oven can be used, it has to be laminated with a second sheet of plain glass of the same size and shape in order to produce a safety glass. This is necessary because the spherical shape of Matrimandir's shell means that large sections of the inner glass surface will be suspended above the heads of those moving around in the building's interior. Thus safety glass is absolutely necessary. The two-glass sheets will be laminated using a resin made specially for such purposes.

The mounting of one of the panels on the inner surface of Matrimandir's spaceframe

White glass from Germany

During the first half of this year, several preliminary samples of full-scale panels have been made and mounted inside the Matrimandir. We have been focusing on the thorough testing of the firing sequence, and details of fixation of the panels to the concrete beams which make up the space-frame of the Matrimandir. The panels will be mounted on aluminium profiles imported from Germany.

As for the glass, efforts to identify the best supplier of the white glass needed to achieve the most satisfactory results in terms of the colour have directed us to Germany once again. They may soon be forthcoming.

Next row of discs

To come back to the structure itself: a team is busy finishing the set of stainless steel horizontal catwalks that encircle the Matrimandir at the equator. These ladders will provide for access to the outside of the building for cleaning and maintenance for years to come. The platform on which the team is perched has been in its present position for about six months. Everyone is keen to finish work at this level and move downward: everyone wants to see the rows of discs appear beneath the equator. There is no shortage of discs, 85 % of the discs is ready, and from this, 50 % is already fixed, another 35 % is hanging in the stock. (If we can keep up the present pace of production, all discs may have been produced by November this year.)

June 15, 01