Using Wood Ash Spray In Ceramic Firing

Yard garden uses for wood ash.

Using wood ash spray in ceramic firing.

The ash from the wood was coating the bricks adhering and melting as a thin layer of glaze. Shino ash wash from sylvia dales 70 potash feldspar g 200 30 wood ash bentonite 2. The process that i m talking about is wood firing with salt thrown in. Jennifer poellot harnetty editor.

The japanese have always held wood fired ceramics in high esteem wood kilns can not only produce temperatures of 1400 c 2 500 f wood fires also produce fly ash and volatile salts. But not all wood kilns are built. Salt vaporizes at a fairly low temperature and can work its way into all sorts of nooks and crannies. Is it only used on bare bisque fired clay or can it be used over a glaze coat under a glaze coat or over underglazes.

I remember visiting a well known pottery in japan renowned for its wood fired pots and seeing a woman swathed in indigo cloth spraying wood ash in a fairly thick coating onto the pots. It requires a very hot dirty firing to look good but also it holds up well in multi day super hot wood kilns. Wood ash is caustic so work in a well ventilated area with a respirator and wear safety goggles and chemical resistant gloves. After mixing with water run the glaze.

The work in wood kilns reveals the story of the firing with pieces showing ash deposits and the path of the flame through the kiln. Wood ash contains all the trace minerals from inside a trees wood which are the building blocks needed for plant health. So check out nesrin s post today. You can build a simple raku kiln and fire your work with wood to get stunning results.

Lately i have read short descriptions of people using soda ash wash on their bisque fired pieces prior to glaze firing and have several questions. In a salt firing the salt vaporizes and the sodium chloride splits into sodium and chlorine gas. The minerals from the wood are restored to nature where they can be reused again. The next step is to weigh equal amounts of ash and redart clay.

Traditionally ash glazes were fired between cones 9 and 10. Does it have detrimental effects on your elements or bricks in an electric kiln. Now with so many fuel options available to the potter wood fired kilns are more of a choice than a necessity. This complex interaction of ash salts minerals in the clay and the flame itself are what give wood fired pots their unique characteristics.

Used as very thin wash dipped brushed or sprayed over shino this mix promotes carbon trapping and can give the look of wood firing. Putting one and one together the potters discovered that wood ash with very little else added forms a glaze. While wood kiln firing isn t easy the results are incomparable. The salt easily glosses up a piece and helps the wood ash flux out.

At this temperature the ash will easily melt and the result to the non purist is almost indistinguishable from pottery fired in a wood firing kiln.