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.

Comments

Rhonda said…
Peter, the latest work is extraordinary, the depth of the glaze colours, such a diverse range of pots etc. You really must be feeling much pleasure from incredibly stunning results. I do believe this work will give you that excitement , to go further. Art is life, Wow!!! Have you nailed it!!!
Peter said…
Thanks so much Rhonda for all your encouragement and practical help! It is a joy to have had some beautiful results from the kiln!
Sue Lloyd said…
Wow Peter. Wow. It was great to read your description of the process. What a time of waiting and wondering.
I love the copper reds and also the more earthy chino glazes. Well done.
Sue
gz said…
lovely bowl...like a pool
Peter said…
Good morning Sue, how lovely to hear from you!
Zero degrees down here this morning, and I guess you will have much the same where you are. Thank you for your support and encouragement!

Hello Gwynneth,
Good to hear from you. I'm looking forward to making more "pools", it is wonderful having a shallow bowl form that will hold a little lake of thick glaze without fear of it running off somewhere unintended!
Linda Starr said…
super firing, great reds, and I absolutely love that bowl
Melissa Rohrer said…
Wonderful- I cannot pick a favorite!
Congratulations on a great firing. Those reds are awesome!
Anonymous said…
Fabulous reduction! Gorgeous glazes! You are in the groove!
Peter said…
Hi Linda, Melissa, Michèle, and Anonymous,
Lovely to hear from you all, thank you for cheering me on! I hope to get to the wheel again tomorrow and make some more pots and bowls for the next kiln load.
Anonymous said…
Just WOW! I've been catching up with your recent blogs, and I thought well, it will take him several goes to get anything worth looking at from a wood kiln. But just look at those copper reds. Delicious, sumptuous, I'm spitting with envy. Well done doesn't quite say it - but well done anyway.
Peter said…
Good to hear from you Mike,
"Well done" much appreciated! I feel very fortunate that things worked out as well as they did and I learnt a lot from the firing. The challenge will be... repeating it!
Anna said…
Wow, Wow and double wow! fantastic results... congratulations and fingers crossed for the next one.
Anonymous said…
Absolutely superb pots, Peter! Well done! Firings such as yours are what keep us going when we've had a firing disaster or two over the years. I guess when we've made enough mistakes and learned from them, the kiln gods shower us with treasures from time to time! Very happy for your success, do keep us posted on subsequent firings! Cheers, Owen in Oregon
Peter said…
Thank you so much Owen for your kind words, it is nice to hear from you all the way from Oregon! I am looking forward to getting my hands in clay again and making new work for the wood fired kiln. I've been a bit diverted from it all for the last few weeks, but... at least I now have business accounts done and some of the more mundane parts of life sorted! Now the studio awaits!
gz said…
Stay safe in this weather xx
Peter said…
Hi Gwynneth,
Nice of you to get in touch. We have escaped flooding, but the main road about 200 metres North of us was flooded last night, and some of the houses near there had water all around. Still raining, but the water has receded somewhat. It is supposed to be fine tomorrow, but another front comes through Monday with more rain! Pxx
Yvalanna said…
Great to see these on this site, Coz Peter! Really like the intense colours and shine you have achieved. That red is a dream colour and the blues are great. Made me wish I was back in my old job but the pottery is more or less disused now. Keep on potting....and HAPPY BIRTHDAY!






Yvonne
Peter said…
How lovely to hear from you Yvonne, thank you so much for getting in touch and for the birthday greetings! I've decided that I'm 95 this birthday... which I am in a sort of back to front way! Pxx
lein ng said…
dear peter,can you share copper red glaze recipe to me ?really crazy with your works!
Peter said…
Hi Lein,

Good to hear from you. The copper red glaze recipe is as follows

Soda Feldspar 45
Silica (quartz) 20
Calcium Borate Frit 15
Whiting 15
China Clay 5
Bentonite 2
Tin Oxide 1.5
Copper Carbonate 0.4

This must be fired in reduction. The glaze seems happiest from Cone 7 to Cone 9, but Cone 10 is definitely too high for it.

The recipe came from a glaze book by Thames and Hudson, but I made some changes to it.

Hope it works well for you.

Best Wishes,

Peter
lein ng said…
thank you for sharing:)
Peter said…
:-) my pleasure. Do let me know if you try the glaze and how it turns out.
Peter

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