First ash glaze test
Yesterday, I tried out some wood ash over a shino glaze and a new ash glaze, which is actually a mixture of a “fake” ash glaze and real wood ash. I was fairly pleased with the results. The teabowl below is glazed with carbon trap shino glaze plus a little mixed wood ash (unwashed) applied to the rim.
I also created a new glaze with the following ingredients:
Nepheline syenite 60g
Whiting 40g
plus one tablespoon of mixed wood ash (raw and unwashed, sieved only).
I only made a small amount for this test firing, next time I’ll measure the ingredients more accurately. This was applied to a biscuit-fired piece of rustic stoneware clay (contains a little iron). This was the result of firing to cone 9-10 in a saggar:
The following pic is a close-up, which shows the tiny crystals which have formed on the surface. I rather like this effect, which happens when the kiln is cooled slowly.
Fake ash glazes are created by adding large amounts of calcium oxide to a recipe. The base glaze I used above is called “Steve’s Fake Ash” glaze, which I found in John Britt’s excellent text, “The Complete Guide to High-Fire Glazes”. In this case, the calcium oxide comes from the whiting (calcium carbonate).
I’m looking forward to trying this glaze out on a couple of pots in my next firing.
