Sunday, 27 February 2011

Smoke firing how-to…



…a little bit boring, don’t you think? I wanted them to be black, at least as black as I could get them using smoke firing.

For those of you who’ve never seen it, smoke firing is basically building a fire around your pots and then putting it out until you have it smouldering to create smoke. Your ceramics need to be low-fired because the clay is still porous. The higher you fire, the more the pores close up so it’s much harder to get the smoke to colour the clay. My pots were only bisq fired to 1000 degrees C.


A good way to get a smouldering fire is to use lots of sawdust. My pots are under the sawdust and there is a layer of newspaper on top to get it going. The slower your fire burns down, the blacker your work will be. Sawdust burns slowly and paper burns quickly so you can easily alter the ratio if you want it lightly smoked.


I set the paper on fire (I’m using our old kitchen bin here with the plastic bits taken off) and then clamped the lid on to put it out and start the smouldering. The bin has holes in it which form a chimney to keep the fire burning. If there aren’t any holes you can leave a gap when you put the lid on.


After the smoking, which took about a couple of hours, most of the sawdust has burnt away and you can just see the smoky patterns on the clay.


After… less boring? The finished smoke-fired pieces have very black areas and white bits where they didn’t get touched by smoke. I could put them back in to get them blacker but I like the variation in colour. After a scrub with a nailbrush the colour stays on and you can leave it matt or use a little wax or clear polish to get a soft sheen.

The great things about smoke firing are that it is really cheap and if you don’t like the result you can burn it off by refiring over 600 degrees C and have another go!


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