Blessings from the Kiln!

Detail of a wood fired copper red bowl from the recent firing of the kiln.

 I am often a little depressed before the opening of a kiln, which may seem odd or be odd... I couldn't possibly say. There are just so many unknowns and variables when glazing and firing pots, especially in a wood fired kiln, that I can only do my best with everything I do, the making, glazing, packing and preparing of the kiln, and the firing, and then wait for 2 or 3 days for the kiln to cool, and the jury to reach its verdict!! The waiting is not an easy time, but it is a time when studio floors can be cleaned, shelves in the store room organised, and some glazing materials put away.

Most of the glazes used in this firing were copper reds, Shinos or celadon. All require an atmosphere in the kiln where oxygen is in limited supply for transforming magic to happen to them, and it is like magic! Green copper carbonate can be transformed to cherry red or pink, a rather nondescript white Shino glaze can become rust coloured or golden, and a honey coloured iron bearing glaze becomes green or grey green, or even blue-green celadon.

Copper red, pink and celadon glazes.

 The firing has been a careful one, abundant oxygen until about 800 Celsius (1472 F) was achieved, and then a deliberate choking and slight over stoking of the kiln until temperatures had climbed to their peak of about 1300 Celsius (2372 F). Firing was about temperature, and time taken to get there, but also about atmosphere, and atmosphere was monitored by eye. Was the chimney smoking, did flames come out of spy holes under pressure, or was air sucked in? Was the flame in the chamber of the kiln hazy, or was visibility in the chamber clear and bright? These are the sort of things that had to be constantly observed and considered throughout the firing.

So there is the firing, and then the waiting for the kiln to cool. Days pass. It is winter and snow falls. There is sleety rain and wind.

Laura having a peep into the kiln.

On the third day after the firing the kiln door is unbricked carefully, one brick at a time. The opening breathes warmth. Hands are put into the darkness of the kiln chamber to check pots for warmth. It is the first contact with the pots. The surface is smooth with a slight dust of wood ash. The pots have a lingering warmth that is almost blood heat. More bricks are removed, and weak sunlight enters the kiln and there is colour and form.

As to the work in the kiln... most things turned out well, or very well, and there was a copper red bowl and a Shino pot that went above and beyond anything I could have anticipated and I will hold onto them for a while and enjoy them!

Bowl approximately 30 cm diameter (12 inches). Copper red and Shino glazes. Stoneware.

The thick copper red glaze was extraordinary.

Stoneware pot with poured Shino glaze. 29 cm high (11.5 inches).

 Those two are keepers. For now!

Shino and celadon platter. 30 cm (12 inches). Stoneware.

Shino platter with sprinkled wood ash decoration. 30 cm (12 inches). Stoneware.

Copper red vase. 26.5 cm (10.5 inches). Porcelain.

Detail of copper red showing pale purple flecks in the glaze.

Copper red and celadon with splash of copper/rutile blue. 18 cm (7 inches). Porcelain.

Carbon trap Shino bowl with copper/rutile blue splash. Dia. 11.5 cm (4.5 inches). Stoneware.

Carbon trap Shino glaze over porcelain, the result is much quieter. 

24 cm (9.5 inches).

Inside the pale Shino vase, the same glaze is much warmer in colour.

Vase with poured black Shino glaze. 22 cm (8.75 inches). Stoneware.

Sculptural vase. Copper red glaze on porcelain. 22.5 cm (9 inches).

I was delighted to be contacted by Jane, a potter living in Vancouver Island B. C. when I was glazing pots for this firing. She asked for some thoughts about a tricky copper/rutile blue glaze that she was using, sometimes with great success, but not all the time! She sent the glaze recipe with the email, so I was able to try it and see if it worked for me.

The results were most interesting and rather beautiful, and I have greatly enjoyed corresponding with her by email about the glaze. From time to time the internet can be a wonderful thing, and it is very nice to feel part of a much wider community of potters and other interested people from around the world. It has been a joy to have met some of the readers of this blog too when they have ventured to the East Coast of the South Island of New Zealand.


I recently watched a documentary about an 83 year old Korean potter and his sons who were making celadon glazed pots. The documentary was made a few decades ago and the colour is somewhat faded, but I found it quite a moving glimpse of the life of potters working in a traditional manner, where making and firing pots was really a form of prayer. The heart and life and work of the potter was conducted in a spiritual manner, in a way that goes far deeper than a particular religion or dogma.

*Technical Notes about the firing (for those who might be interested in such things!!).

All areas of the kiln had good reduction, and the temperature variation from top to bottom of the kiln was about 2 cones, from an estimated cone 11 at the top to cone 9 at the bottom, and most of the kiln being an even cone 10. In every day terms, that is about a 30 degree Celsius (86 F) temperature variation. This was a marked improvement from the firing before that had a 3 cone variation from top to bottom, or something in the order of 45 degrees Celsius (113 F). The improvement had been achieved by spacing the lower shelves wider apart than in the first firing, so as to let a greater flow of flame through the setting there.