19 September 2011

Firing 21

Firing 21
5am first sign of dawn. Cloudy but dry with south westerly breezes. Discovered I am very low on gas for the initial warm up. Stupid oversight, hope the local shop has a bottle in store as I have a lot of raku firing to do too - not today though. (When I started rakuing 15 years ago a 19kg bottle of propane cost £11 today it cost £38). Awake again at 7 and the gas has lasted, kiln at about 100 C. Turn gas up and back in to make tea only to find Non Potting Partner has already made it (all previous complaints withdrawn).
Start to feed wood in around 8 o'clock and continue with both until 9.30. Turn the gas off expecting quiet to descend only to hear the rumble of the forest being felled (mustn't complain it's community owned now and I'm thinking of all that scrap wood to be gleaned) and then NPP starts up the mower to cut the lawn.
A few spots of rain, a crunchy James Grieve apple fresh from the tree and into the rhythm of stoking, concentrating now to avoid losing temperature. The last few firings have followed a very close pattern, apart from the previous one fired in a south westerly gale and an hour faster.

More tests in this kiln. Trying to find a white shino type glaze which gives results with this firing cycle. I have a rather drab white which matures but is dull, and a lovelier snowy white one maturing at cone 10 which I struggle to achieve. There are also tests with the new Scarva black body which has been firing very black but very dry and needs a little sheen or sparkle to liven it up a bit. Plus, of course more pieces for Philadelphia.

1000 C at 12.40
1100 C at  2pm
1200 C at  6.30pm

2 comments:

  1. Hi, I come across your blog by accident, I notice your interest in Czech - Cesky Krumlov -I started reading. I realized you have kind of kiln, which is very common here in Czech - are you Czech? When I read here that you search for white shino I decided to write you – as we also use same type kiln, this recipes could work for you too. White shino: Custer feldspar 55, soda spar 20, kaolin 15 and ball clay 10 – nice white shino, which if apply thicker crawls. Also we very often use glaze: Nepheline syenite 85, kaolin 15 + add bentonite or gum Arabic. Regretably, I do not know what is this kind of glaze going t do with soda – I have never use it in soda firing. My soda kiln is in plan for 2013 or so. Also I did not get couple of things: Why you use gas to preheat and why do you have grate in your firebox? Hope to hear from you and maybe, If you visit Czech Republic, to meet you – fellow potter from Czech – Miroslava Randová - www.kcdoupe.cz or www.artkeramika.cz/keramikstudio

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  2. Apologies for taking so long to reply.
    thanks for the glaze recipes, I will try those.(My drab white shino is potash feldspar 40, nepheline syenite 40, kaolin 20. and it fires beautifully in a longer anagama firing but not good with shorter firing).
    I use the gas pre-fire to dry out the kiln slowly, it's a very wet and humid part of the world and as I fire solo it shortens my day by 2 hours.
    I'm not czech but we visit often and I got this kiln from the czech republic! No surprise that you recognise its type. It came with a shallow grate and 80cm long fire bars running from front to back which broke very easily. I rebuilt it with a deeper grate and bars from side to side and a 'mousehole' to bring air in through the ashes. This means I get less choking of the ash pit and can use a door on the fire mouth.
    I look forward to meeting you in Czech Republic. Your work is very interesting and I would like to see more.

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