yesterday I opened the third go at this new world of saggar firing. it had been a slow firing, partly because I was trying to allow the heat to get into the saggar, and overnight I didn’t turn the pressure up as much or as quickly as usual. then it was even more difficult than usual to get a good steady balance of rising temperature combined with visible signs of reduction – sooting up of the cracks in the clay around the bricks at the front, and a flame from the flue exit. I had glazed all the pots in the front part with the same combination – the barium “chalk beach” glaze underneath and a layer of the copper/tin/dolomite glaze on top. I tried this on a couple of pots and called it “saltings” in the first saggar firing. these were fired pretty hot, as they were in the middle of the top shelf, and came out as a pale version of the “saltmarsh” copper/tin/dolomite. no such thing occurred on these six pots placed at the front of the kiln in this firing. I am not sure if it is cooler temperature, thicker coat of the second glaze, or lack of reduction, perhaps a combination of all three, but they were all a soft metallic grey or greenish grey with orange breaking and copper green on the edge of the join with the barium. plus two had crawling and peeling off, which is actually rather pretty but very fragile.

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on this one it is a small area, and we are going to show it like this at the Bircham Gallery in October. on the other it was pretty well all over, so I took it all off, and I still like the result.

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they both have scratched lines and little bumps under the glaze, which are more obvious where the glaze has come off.

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this is the white stoneware, and it is one of the pieces that went up to about three or four hundred C in the first attempt with the cardboard saggars. the orangey blob is where there was a carbon stain on the piece – a very fortuitous stain.

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as for the pieces which were inside the improvised saggar – in which the sawdust had burnt right away again; and this was no doubt due to air getting in low down, as Sebastian Blackie suggested it would be, since I used two big silicon carbide shelves which have slits in them – they were mixed, and there was very little black or grey, but I am still pleased with the result. one thing I hadn’t expected, although I should have, I guess, was that the sheet of cardboard which had been left in had an effect on the firing, and strange brown ashy remnants of it were still there when I opened the saggar up.

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where it landed on pots it left a shiny glazed surface.

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first of all, I couldn’t be more pleased with this piece, the carbon marks and flashing work so well with the porcelain marks on the toasty st thomas clay.

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now I have a group which work well together. (they will be in the Bircham gallery show too)

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this little porcelain incense burner has been fired three times now, in my vain attempt to get it grey and black, but now it is really quite interesting, so I will probably leave it like this. it has a piece of cardboard glaze on its shoulder.

the top temperature of the firing in the saggar was not too different to the firing in the front of the kiln, although a section of the ceramic insulation board I used as a lid bent and collapsed, doing this to the cones

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but as far as I could see they are melted to about the same extent as the ones in the front.

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this has been affected much less by excessive heat than the similar but bigger piece in the previous firing, but the stains and flashes are more overt.

I am giving this a rest for the time being as  the Beaux Arts exhibition in Bath is going to take up most of the coming week, but I shall buy some low firing ball clay to make the right sort of slip and have another crack at cardboard saggars as soon as I get some time, thanks to Sebastian Blackie’s kind advice and encouragement.

the rest of the pictures of this firing are here.