With Ye Olde Photographer's usual bad timing, he missed the actual firing and the transfer of the hot pieces into containers for reduction. But at least we get to see some results. The work was removed, still smoking and covered with ash from the crumpled newspaper and sawdust used for reduction. At this stage, some work was quenched in water to bring down the temperature, then the smoke and ash deposits were scrubbed off to reveal the magic.

On the following week, better timing and more activity provided a chance to see and photograph most of the various steps over the course of two back-to-back firings; lots of exciting stuff to see.

And on December 8th we got just a few shots of activity on the kiln deck.

The raku process starts with bisque fired pieces similar to other methods; clay bodies more tolerant of thermal shock may be used. Glazes are applied and dried, then the work goes into the raku kiln. The kilns tend to be relatively simple. The work may often be observed through vents in the top, but pyrometric cones may also be used to check firing temperature. The work is raised to a temperature where the glaze has melted and flowed. Unlike other firings, at this point, the kiln is opened and the red hot pieces are removed and placed in containers surrounded by combustible material - sawdust, paper, leaves or pine needles. The material ignites and the carbon content reduces many of the glaze oxides. The containers are immediately closed and allowed to cool while the work is exposed to the resulting reduction atmosphere and is in direct contact with ash from the combustibles.

After the pieces have cooled substantially, they may be removed, after which they may be quenched in water or misted with water. Eventually the pieces are scrubbed with mild abrasive and scouring pads, bringing out the often brilliant irridescent effects of glaze being reduced all the way to pure metallic elements. Copper compounds are particularly useful for these effects.

In the transfer from kiln to reduction, the need to work quickly, combined with the need to handle the work very carefully and the hazardous temperatures involved, requires a good deal of coordination and attention. At its peak, the process is quite exciting to watch, let alone participate in.

Fall 2012: There is a gallery of ConEd raku fire activity in the Dave's ceramics section.