another firing … and this time I was determined to get the reduction right. for some glazes I really don’t want this excessive reduction, but now I am working with ash and a lot of bare clay it needs to be really toasty – and hot.
I stopped the reduction at top temperature and soaked for half an hour at 1255C – and that sent cone 11 over, so it was a hot firing. I had a huge red flame coming out of the flue all the way up from 1100C.
there was one fatality – the big bottle looks very overcooked, the pizza clay has gone a nasty buff colour and the barium glaze really didn’t work on it.
and a lot of the unwashed ash melted and ran onto the shelves.
but it was worth a bit of chiselling and drexel grinding for these glazes.
the unwashed ash leaves a halo of flux that has soaked into the surrounding clay, and pools of glass where it runs into hollows in the form.
the jar lid stuck very firmly to the shelf, and came away with big chunks of shelf attached. my little drexel drill with its tiny carborundum disc tidied it up enough to fit into the jar.
this is the glaze that Steve Parry, my wood-firing and kiln building potter friend, uses. in his version, the pine ash from his kiln gives him a nuka glaze, thick and creamy, opaque and runny. I have used utile (an african hardwood) ash and it has made a beautiful celadon type of ash glaze. all ashes have different chemical compositions, which change how glazes made with them work.
this bowl has the unwashed ash, and underneath are solidified rivulets of melted ash. the heat of the firing made the bowl sit down onto the shelf slightly, so another tap or two on the chisel was needed to get it off the shelf, and some more work with the drexel.
now the part that was stuck to the shelf is smoother than the rest. a thick layer of batt wash covers the shelves and mostly prevents a permanent weld.
I have used the oxide slip and chun glaze combination on three of these flagons and a bowl, but I have to be careful, at first I put the layers on too thickly and it all started to peel off – so I had to scrape it all off, sponge the oxide layer to a more washed out consistency, and re-slip and glaze the pieces. because of that I was a little conservative about the thickness of the slip and the glaze the second time around, and they have come out with much less crawl than in the last firing.
but the oxide was very thick in certain places and it has bloomed through the slip and glaze.
unfortunately I could not resist the extra bit of thickness in the bowl, and the crawling has turned into raised cracks just where you don’t want it.
however, these bowls are more decorative objects than functional.
but these and the last firing’s flagons represent a huge step forward in the use of slip and oxides and decorative looseness
which together with what’s happening with the ash glazes seems to me to be a quantum leap in my practice. here’s the link for photos of the whole firing https://www.dropbox.com/sh/r1hvqyydjxhuym8/NgmumsxoiS
meanwhile everything is blooming in the garden and the countryside around Bale and deserves a blog post on its own.