Tuesday, February 5, 2008

Cone 6 Wood Ash Glaze


This is the AG-19 recipe /AKA/ Mark Issenburg /AKA/ "Ashpot" 50/50 Red Art & Wood Ash with added 5% red iron fired to cone 6 electric and "bumped" in the cooling process; when it cooled to low dull red it was spiked back up to orange heat. I think that I want to substitute Alberta for the Red Art and see if it moves a little more. That and add maybe 1% copper and 1/2% cobalt (?). Originally the AG 19 is a clearish green glaze fired in reduction cone 10, or so I am told. There is a similarity to the recipe of Leach's Tea Dust (from his Potter's book) which is 50 raw ochre (a clay rich in the yellow iron-bearing mineral limonite) and 50 wood ash. I think the basic skeleton of these glazes is 50% ash and 50% fusible (as opposed to vitreous) clay. Naturally squirrely since it has no feldspar to broaden the firing range.

3 comments:

Ad beales said...

I have fired the 50/50 recipe to cone 10 reduction. I used unwashed ash which is much fluxier than washed ash. Also hard wood ash contains more fluxes which will help melt the glaze at lower temperatures.

Ad beales said...

I forgot to mention that the glaze is not a teadust, it is a fairly deep green with stringing, a feature of many ash glazes.

Lee Love said...

Bob Briscoe fires this glaze to cone 10.