at last, a firing from which every piece came out well. besides getting the right glaze on the right pot at the right thickness, and placing them in the right position in the kiln, real attention to detail during the firing is needed to achieve a good result.
an amazing green flame through the 1200′s, as I tried to keep the reduction light. between 1030 C and 1100 I had a strong smoky reduction, a little flame peeping out of the spyhole brick, and a very strong sulphur stink.
the last cone which is only a little bent is cone 11, signifying if bent over fully, 1300 C, or the equivalent heat work – I turned off the gas when the pyrometer read 1262; the slowness of my firing and the reduction produce the same effect at the lower temperature. the floor of the kiln at the front is a bit of a dead area, I get a better result by raising the pots up a little, though I did slip a porcelain stem bowl underneath. the southern ice porcelain matures at a lower temp anyway.
at the back the pots on the floor fire well, as long as they are well spaced out. my crazy blue glaze toned itself down a bit this time, probably because there was a little less reduction, so the copper in it stayed green rather than pinky purple.
I had three refires on this top shelf, two were underfired in the cold spot at the front of the kiln in the last firing, the other was just a dull colour with a lot of grey.
this firing has a nice mixture of colours – orange, rust, chocolate with blue bits, a purer, veined blue on the second glazed porcelain piece, and grey green to celadon green.
this bottle was on the top shelf at the front, next to the flue; that’s probably the hottest place. this is the dolomite/tin/copper glaze, fairly thin – a wonderful glowing dapple orange/rust that sometimes happens on the super white stoneware.
the same glaze on porcelain when thinly applied almost disappears, and will turn pink where there’s enough reduction. this has had its second firing; the first left grey patches where the copper was a little thick. more copper burns off this glaze in the second firing and lightens it up.
the new shino I mixed up in January for a liner will come up white when it’s on thick enough, so the indented polka dots catch more glaze and are white. the clay is that “school clay” a buff stoneware, which turns this rich rust under the shino.
this porcelain wash has proved difficult to glaze satisfactorily. it is a cold white, so colour in the glaze tends to be less rich and warm and the surface can be rather uninteresting. it is better when the wash is thin and allows the buff clay underneath to show through. dipping the bottle sideways in the two different dolomite glazes, the green and the blue, gives the shape some help too. I call the vertical overlap a tidepath, referring to the tidemark I make by overlapping horizontally.
the blue dolomite glaze at the right thickness does very good things on the layering of the superwhite stoneware over iron-bearing stoneware. these watering cans came when I was using images of a french collection of old watering cans to make an embroidery for the summer knits. the idea of making spouts with sprinklers was too tempting to resist. I think this is the one with the most presence.
this is the blue glaze behaving itself over porcelain layered with terracotta, and doing what I originally got on my porcelain tile tests; a speckled bird’s egg blue.
working outside, glazing and packing the kiln, has been a pleasure this week; my garden is owned by a thrush, and he has been singing for a week now, starting with a throat clearing, lung stretching series of spluttery croaky noises which developed to full blast jazz song by mid week. sometimes I could hear three, two far off in opposite directions, and “my” thrush low down on the ivy hedge next to the pottery workshop, very loud.
you can see all the pots from the firing here