07 October 2009

Ceramics week 4

First the results - someone's glazed fired pot, with steel wool turned into oxide (brown), and the green copper glaze, run together with a tin glaze (white) to produce the pink areas -Someone else had put balls of white and red clay into a mould, and filled it with black slip -
The piece was cut in half horizontally with a wire, but not all the way, then opened up with the "spine" intact - how gorgeous is that!My results - the best bits are the unplanned bits -
The lesson was slip glazing. First, some slabs were cut and one pressed into a mold -
the edges trimmed with a wooden implement (metal might scrape off bits of plaster, which tends to explode in the kiln) - optional edge treatment -
After rather a lot of white slip was poured on and tilted and rotated to cover the bowl and slab, dots and lines of black slip were added with a slip trailer ("they're inclined to spurt") -
then moved about with a needle. Tiny amounts of underglaze colours (powder) can be sprinkled on - and the slip sprayed with water to get a dimpley texture -
In the afternoon, a demonstration of saggar firing, or rather, packing the box. It was at this point my camera battery ran out -
The inside of the box shows the kind of smokey finish that this produces. All sorts of organic things give different flashes of colour. One pot went in wrapped in a banana peel, for instance. A roll of wet clay holds the lid on, so that there's no oxygen for the burning, just charring.

We also learned a bit about the earthenware and stoneware glazes, and how to dip pots into the glaze ("in one smooth movement" - hah, not as easy as it looks!). I glazed a "tideline" onto some of the pinchpot "barnacles" from the first week. Looking forward to seeing how that looks, but apart from that the day found me confused about what to do first and what to try to ignore for now. Too many possibilities (have I said that before?)... And of course what the others are doing can look much more exciting and successful than your own work!

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