|Monthly Tech-Tip |
I always put the emphasis on ash glazes with functional surfaces, well melted, uncrazed and resistant to staining or cutlery marking. This version gets its color only from rutile. The glaze creates a more decorative surface when applied thinner (like the inside of this small vase). When thicker the surface is functional (like the outside surface). Ash glazes can be very stable (resistant to running during firing) if they contain enough Al2O3 (mainly from the kaolin) but also from the feldspar.
Wood Ash Glaze
Common washed wood ash has a chemistry akin to a ceramic glaze, so it can comprise significant percentages in a recipe. Plus it can produce unique visual effects.