another firing, a more successful one this time

spring has come on a lot since my last post, we have had a good three weeks of mild weather. along the edge of the wood hazel catkins dangle,  smudged dashes of pale green against the brown-grey winteriness of the trees, one of the first signs of spring.

crocuses and tiny irises are out in the garden, and all the snowdrops that fringe the wild garden are at their best.

mild weather has made working in the pottery, especially glazing, which I do outside, on the verandah, much more pleasant. on Friday I had another glaze firing, after two weeks of making, and a biscuit firing. now I have plenty of pieces to glaze, at least another kiln-full after this one. I made the pack looser, and applied some of the things I had learnt from my last firing – at the moment the kiln arch has some leaks and the gap made by the bricks on the top of the flue needs to be quite a lot smaller to get the right amount of reduction.

I started reduction a little early – at 1009 C, and kept it strong with real back pressure and a lot of soot for the next 100 degrees, then allowed less reduction, keeping the flame that emerges from the flue quite small and clear. it turns out I could really have had even less, and kept the copper glaze a bit clearer.

a lot of the pots are made with an iron bearing stoneware, or even crank, with a layer of a very white smooth stoneware rolled on top as a layer. the white clay gets marked with stains from the iron bearing one, and it results in an interesting mix, with which the dolomite/tin/ copper glaze works very well, producing oranges, rusts and an almost celadon green, although matt.

the blue version of this glaze has turned out to be quite problematic. I have had greys and blacks from it mostly, except when I use it for a second firing over the barium glaze. however this time the blues are quite bright over the porcelain layered pots. this was due to the fact that I put it on much thinner; in order to do that I did not mix up the whole of the bottom of the bin ( this was still in a solid lump after the big freeze) so possibly the composition was different.

the refiring of  the last firing’s disaster was even more of one, the glaze has bubbled so the poor pot has an advanced case of acne. I don’t know why and will have to ask advice on this one.

on the whole a good batch. I am not so happy with 2 more strident blue pots hiding at the back of this group, (one was at the front of the kiln) but the blue is better on this one, as the copper in the glaze has kept a slight greeny tone, instead of the purple of over reduction.

this group of little bottles has turned out nicely, glazes doing different things depending where the pot was on the shelf. centre left is the blue glaze again, but over stoneware clays which tone it down.

the best glaze for my rough white stoneware mixed clay is the crawling shino, and this is probably my favourite pot. its pointy shoulders are working nicely with the double dip down the middle, and the cracked wall echoes the crawling shapes.

I made this pot in the summer; it’s good to have it resolved at last – and the green/orange dolomite glaze is stunning on the iron-bearing stoneware on the inside. I have a web page of photos up here.

a new batch awaits firing in the workshop, mostly only just small enough to fit in the kiln

this is reduction st thomas clay with added grog – there are several made with the rough white mix, and some with black clay, both of which will look good with the crawling shino. probably the st thomas will get the dolomite glaze

and this, which is st thomas with wet porcelain and china clay rolled into it, will be best with the dry matt barium glaze.

after looking again at this firing, I want to have one of these in the stoneware layer, using crank as the base and the fine white stoneware which has molochite grog in it as the top layer. it has been producing some lovely results with the dolomite/tin/copper glazes. so more clay out and some more making this week. at least three more firings to go – much intense forward visualisation at this point.