Tuesday, July 12, 2011

Natural Ash

Wadding separates two pots

Many of the pots I fire in my Manabigama kiln are glazed naturally by my kiln. The finish on a pot is highly affected by where it's placed in the kiln. Put a pot facing the flame and it's likely to have heavy ash buildup. Place one directly behind a pot and the flame's effect will be much more subtle.

I've fired this kiln 17 times, and the surface of the walls are beginning to flow with natural ash buildup. I imagine what it's like to be a pot inside the kiln during peak temperature when everything is in some state of flux. Everything is glowing, nearly white. We're constantly stoking to keep the temperature up. Everything is engulfed in this mixture of gases, ashes and volatilized minerals.

I don't pretend to know the chemical process of what's going on. Early in the firing process, pots in the kiln are dusted with light wisps of ash. Twenty hours later - stoking every 10 minutes or so with Pakistani hardwood from pallets and slabs of pine from a local sawmill - ash has accumulated and melted, molten minerals have built up.

Depending on the cooling process of the kiln, the heavy ash buildup can be shiny or matte. We cool slowly, so we get matte. The heavy ash deposits thin out and create a speckled surface, finally thinning to an earthy orange and copper.

I can't wait to unload the kiln.

The undulating vase is a collaboration I did
with Phillip Pollet for the gala auction
at this year's Celebration of Seagrove Potters.

Ash buildup on the walls

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