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Making Walls by Extruding
We had an idea about stacking extruded tubes and glazing them on the inside, so the viewer would have an experience of coloured light coming through the tubes.
We worked on developing the idea further, having ideas about a shape that was interlocking, and could be stacked without mortar. We explored different shapes, and in the end we found that a hexagonal star shape would give us what we wanted. We then started exploring the shape of the hole in the star tubes, and discovered that with an irregular shape we would get a diverse pattern when stacking the tubes, and it would look like the tubes had different types of holes in them, when if fact it would be the same hole, only rotated.
Our idea was to make a wall that would be about two metres tall, so we realised that we needed to produce a lot of tubes. For three days we used the extruder, and managed to produce 617 star tubes. After shrinking in the kiln, this would give us a wall of 3,1 square metres.
To get the bright colour that we wanted we had to firstly dip the clay in angobe, a white substance, to get a white background. By glazing the clay without angobe would mean having the clay’s own colour, dark brown, as background, and the colours wouldn’t be as bright as we wanted. We bisque fired all the elements before we started glazing. The reason for this was to prevent the clay from exploding in the kiln, because when you add moisture, glaze, to the dry clay pieces it can be destroyed.
Then the mixing of glazes started. We chose a blue , high temperature glaze, as our main colour on one side of the wall, and planned to to have the other side of the wall in a grey metallic colour, with some elements of other colours here and there.
The reason for using a high temperature glaze was that the clay we used needed to be fired at 1280°C. When firing clay on high temperature, the pores close, and it is more difficult to apply the glaze. Since our elements were to stand outside, we were recommended to use a high temperature glaze for this project.
The tubes were dipped in glaze from both sides, leaving an area in the middle free of glaze, which was needed for when the tubes was to be fired, the glaze can’t touch the kiln shelves, then they will glue themselves to the shelves, therefore the tubes needed to be balanced on a small piece of kiln friendly material.
The tubes came out of the kiln in all sorts of shades of blues, greens and greys. Depending on the mix of the glaze and the temperature of the kiln. We had planned that the colour would be unanimous, but the result with all the different shades were definitely more exiting.
Problems with glazing
During our work with glazes we encountered many of problems. Every glaze had to be tested on the specific material it is being used on, so we had to fire tests of all the glazes we wanted to use. One of the glazes was wrongly labeled low temperature glaze, and fired at 1280°C it sprayed all over, and ruined several kiln shelves. An other one would not mix, and instead of being similar, all the pieces with this glaze came in different varieties. During the firing in the kiln some of the glazes dripped, came out the wrong colour or had in some places slipped right off the clay.