Monday, June 1, 2009

Firing the wood fired kiln.... A Great Result!

Flanked either side by friends Graeme on the left and Peter on the right, I peer delightedly at a little bowl that has just come out of the wood fired kiln. It was a great firing, what more can I say! (Peter was the man responsible for getting me started potting and I like to have him at my kiln openings.)

A first look into the kiln after the firing. After a 13 hour firing the kiln reached almost cone 11 at the coolest place, and over 12 at the hottest.

Quite a lot of the work had developed subtle lusters, and some of the shino glazed ware was particularly good.

I glazed the inside of some of the goblets with a glaze that is shino like in composition, but it contains some petalite and iron oxide. In a previous firing this gave a bronze, but this firing yielded something nearer to gold.

Most of the large bowls worked quite nicely. This is a chun glaze, which is not showing up all that well in the photo under poor lighting, but was spectacular in daylight.

I had some problems with copper reds that I put on some of the smaller pots, this large bowl worked really well. The white clouds were washes of titanium that brushed on the glaze.

The clouds developed a wonderful blue edge.

This large bowl was hard to photograph as the black shino under glaze was very lustrous, but the poured blue chun glaze and copper red glaze made a nice abstract composition.

That shows up in the detail photo.

This is a slightly strange coloured bowl, a purple with red and green tendencies!

I think Laura really likes this little shino glazed milk jug.

This small jug is one of my favorites. I threw it when I was doing a series of mugs and wanted a slight change of form to keep me interested.

This 9 inch high jug was inspired by my visits to Doug Fitch's blog, A Devonshire Pottery. Doug does lovely earthenware pots in the English Slipware tradition. I love his harvest jugs and puzzel jugs.

I tried a combination of glazes that I haven't done before with this small bowl. There is a calcium matte glaze on the outside and a copper red on the inside. I am pleased with the way the calcium matte starts to run into the copper red where they meet.

This chalice has what could have been a copper red on the outside. Fortunately the oxidised version of the glaze looks good, and it didn't matter that it failed to have enough reduction in the firing to turn it red.

This vase has Malcolm shino on the outside, a recipe that I haven't tried before. It is a carbon trap shino that contains sodium silicate. The orange coloured decoration was achieved by painting masking solution onto the pot after glazing it. The sodium silicate crystallizes on the surface of the unmasked areas and fires differently there.

I showed photos of most of these teapots in an earlier post as I was constructing them. So this is how they turned out after glazing.

















Sorry for the vast number of photos on this post, most of you have probably gone to sleep by now (as in the good old days of family slide shows!). This was actually just a sample of the firing as I haven't photographed all of them yet.

To sum up. Most things worked out really well, but not always quite as intended. Copper reds often stayed green, and some Malcolm Shinos were over fired and strangely wrinkled. My usual shino seems to be more tolerant of excess heat. Most of those affected were still quite acceptable though. I had one disaster with a large bowl that was in the hottest part of the kiln, the glaze ran in two places and stuck it to the kiln shelf. Unfortunately a large part of the foot ring parted company with the bowl as it was separated from the shelf. A small jug and a small bowl both suffered from a snowfall of kiln wash. In spite of my attempts at cleaning the loose stuff off the underside of the shelves.

The problem with the copper red staying green in some cases was due to the difficulty I had in getting the kiln to temperature. I had to fire in oxidation at times through the last few hundred degrees to persuade the kiln to keep on climbing. Some of that was caused by rather dubious wood. Never mind! I will have a play with the fire box as I have got a couple of ideas that might make it work more efficiently and cope better with wood that is sub standard.

18 comments:

Linda Starr said...

Wow Peter you got some spectacular results, congratulations. The teapots are beautiful as before I love the coppery/gold colors; I really like the purple bowl but purple is one of my favorite colors; your shinos are beautiful too and the chun as always. The large bowl with the black shino is very nice. I know what you mean about not being able to photograph it well - I had a bowl like that - some of the metallics are hard to capture on film. I see why Laura likes the little shino milk jug - that is a real gem. The bowl with the calcium running down is beautiful as well - are those cooling crystals in the bottom of that one? What is the masking solution you used on the Malcolm shino vase? I love that one too. The gold inside the goblets is beautiful. I think my very favorite is the last teapot you have shown. I love the balanced shape of the pot and the handle and love the dark glaze too. Laura's milk jug is a close second, maybe a first too. I wish I lived near, I would drive over there in a rush to see all your beautiful pots - great work and such spectacular glazes you have achieved through your diligent firing.

Peter said...

Hi Linda,
I am quietly rejoicing at this end of the world! It is such a relief to have a good firing. I think you are right about cooling crystals in the bottom of the little bowl with the copper red and calcium runs. When I think about it, that is quite likely as the bowl was placed close to the arch of the kiln and I have noticed that this holds onto the heat well whilst the kiln is cooling. I had a similar thing happen with a copper red placed there a couple of firings ago.

The masking solution is one of those brushable liquid wax solutions for doing wax resist and waxing bottoms of pots.

I always did like the form of the last teapot too, and I glazed it with that "black" shino that I have been experimenting with. It is just my standard shino recipe plus 8 percent red iron oxide, 4 percent manganese, and 2 percent cobalt carbonate added. I am sure that many other shino types of glaze would give a similar result. I am also going to try to extend the range further.
Wish you and Gary could drive over (just watch out for that stretch of water!!), it would be really fun to talk potting and plants and all sorts of good things!

Arkansas Patti said...

What a wonderful sense of pride you must be feeling. What a transformation. Would be hard to pick a favorite but that chalice is close.
Must be wonderful to create such beautiful things.
Keep the pctures coming. No one here sleepy.

Dad said...

Wow Peter! Lost for words!!!

Becky said...

GORGEOUS results, Peter! While I lpve them all I have to say the purplish bowl caught my eye from the first group shot. It's breathtaking! You have to be so pleased...and also ready for a well-deserved rest. If you ever decide to sell that bowl, please let me know. Oh, in your previous post, those birds? I'd like to know more about them too.

Peter said...

Hi Patti, I think that some sort of primal "whew..., that's a relief!" comes closer to it. There is a glow of satisfaction there too as I am really thrilled with how a lot of the pots have turned out! Sometimes the process of wood firing "blesses" the work and does nice things that are the result of all the complexities of the packing of the kiln, the kiln atmosphere, dryness or dampness of wood, the stoking, and the weather, and there is an element of good luck involved. I'll certainly keep the pictures coming.

Hello Dad, so glad you were able to see the photos and share seeing some of the good things that has come out of it with me (after all, I couldn't have got the kiln done without you!)

Hi Becky, thanks for the nice comments. The birds in the previous post were made by a little group of teenagers that come to me for an hour's lesson on Wednesday evenings. We made the birds as an exercise in working with clay. The birds are about 8 inches long, but will shrink a bit when fired. The clay is heavily grogged earthenware. The bodies were made from two pinch pots joined rim to rim to form a ball that was then pushed around until it was roughly egg shaped. Then a head was made from a tiny pinch pot, and after that was attached, slab tail feathers were added to the appropriate end of the body, and beak and eye added to the head. They are still drying at the moment, but I hope to be able to bisque them and get my little crew to glaze them in the next few days.

Regarding the "purplish bowl in the first group shot", do you mean the one that is in the third photo down that was taken outside with an assortment of other pots around it?

That bowl measures just over 13 inches in diameter and has a copper red glaze inside and a "black shino" glaze outside that is actually nearer to a dark bronze colour and fairly lustrous metallic bronze on the rim. The inside red glaze is quite complex and ranges through to greenish shades where it is thinning up towards the rim, and has deeper red tones lower down.

What I will try and do is photograph all the work tomorrow in better light, and very soon put together a selection of photos of the pots on line with their sizes and glaze particulars. Most of my work from the firing will ultimately be for sale. I have an exhibition in Dunedin that I will need some of it for that is later this month so I need to select work for that, and work out prices.

I am still investigating best ways of selling work on line, and also looking into postal options, but I am sure we can arrange something in the very near future for you.

Jewels said...

Way to go Peter! I am very happy that you had such a successful firing! I love your pots! Gorgeous glazes that complement your forms very nicely! The large bowl with the black shino with the blue chun and copper red glaze on top is spectacular!!

Kudos to Laura for being there by your side, cutting firewood and stoking the kiln. And we should all have such an adorable kiln god to watch over our pots.

You have had so many excellent blog posts that I am just now reading. I have to say you are making me look bad with your multitasking. I was speaking with Patti and making excuses for not blogging (I have been working on my shop), and I got tickled when she said that Peter makes all that pottery, fires his kiln and still blogs (not to mention appeasing the kiln god with affectionate pats). I am very glad you do as I truly enjoy learning your process and seeing all your beautiful work! I wish I could snap my fingers and be there to experience the firing and unloading first hand (of course I would need to be able to snap several of your pieces back home with me too).

Thank you also for all the beautiful pictures of nature in New Zealand! What wonderful scenery you two have to take walks in and rejuvenate. I can imagine being there, soaking up earth’s energy, and being so enraptured by the surrounding beauty that running wildly and screaming with joy (or barking if one were a dog) would seem like a natural thing to do.

BTW – my favorite teapot is the next to the last one. Delicious!

All the best to you and Laura! Jewels

Peter said...

Hi Jewels, It is so nice to hear from you (and good to see another post on your site too!). As to the multitasking, I think I must have reached some sort of new level this afternoon. I was really tired, but took some photos of some of the work from the kiln, and was busy editing it on the computer. I fell asleep whilst working twice before having to admit defeat and go to bed for a while. The funny thing was that one time, when I woke up at the computer, I was still editing the picture that I had fallen asleep with, but, I had selected a completely different tool and was busy skewing the picture into a strange distorted shape. It was quite amusing really. Maybe I can train myself to do useful work on the computer in my sleep!

Glad you have enjoyed the blog posts from this distant part of the world. It is nice to try and share some of the process of making and firing the pots, as well as showing our environment. I wish you could come over and see it all (you would have to bring Patti with you, I would insist on that!). Keep on snapping fingers and wishing, it might just work!

The next to last teapot has a really lovely glaze on it that seems to like being wood fired. The recipe is in an old book by a British potter, Tony Birks. I am probably firing it one or two cones hotter than it was intended to be, but it just keeps getting better. This time it really has a metallic luster to it and is amazing in good light. The simple brushed on decoration is a thin wash of titanium oxide. The teapot would hold about two mugs of tea.

Jewels said...

How funny that you awoke to find yourself ‘working’! That is the ultimate in multitasking! Glad to hear you will be posting more pictures of your pots (though anxious to see them, we can wait until you get some rest). : )

I will be sure to bring Patti with me as soon as I learn to snap my wishes into reality (or win the lottery). I know she would enjoy visiting with you and seeing NZ too, and I would love to have her as a traveling companion. Like you, Peter, Patti has the wonderful ability to bring joy to others. I met her six years ago at a women’s cancer support group. She keeps us all in stitches with her keen sense of humor. On top of being lots of fun, she is all together a loveable human being. I adore her.

Peter said...

Hi Jewels,
Thanks for introducing me to Patti through your blog, it has been wonderful having my life touched by warm rays of goodness from Arkansas.

It sounds like you may have met Patti when things were tough for you (probably the understatement of the year!). It is funny, but I started this as a pottery blog, but I seem to be finding that the real importance of it for me goes way beyond clay and glazes. It is people, ups and downs, kindness, thoughtfulness, and friendship that takes pride of place.
Best to You, P.

Dad said...

Hey Pete... I'm still lost for words.
How come my son not only pots well, computes amazingly, writes beautifully, but also empathises superbly?
The only problem with coming onto your blog (apart from the intrusion) is the time I then spend full of admiration for what you're doing AND for the lovely folk who write to you... AND then get hooked onto one of your ref sites into the bargain.
Never mind, there are worse ways of spending time... like filling out the spread sheet for this year's tax return expecting a credit, only to find that we both owe some!

Peter said...

Thanks for that Dad, lovely to hear from you, you are doing well for someone "lost for words"! Agggggggggggh, the dreaded IRD stuff, yes..., guess what I have still to do this month! Ah well, at least it is cold and gray out there and a good reason for being indoors tucked up in front of the glowing screen and the box full of paperwork!
Glad you are following the links to other blog sites, there are some wonderful ones out there and wonderful people too. Much to learn and rejoice in. P.

Pat - Arkansas said...

Beautiful, beautiful, beautiful!! Oh! how I wish NZ was not so far away! I would love to see and touch your beautiful work! Love the teapots! Love the bowls! Love all of it!

You have every right to be happy about the firing!

Peter said...

Pat,thanks so much for that. I'm wishing NZ was not so far away from Arkansas, as I would dearly love to meet up with you kind and thoughtful people. I'm getting rather fond of you all through your blogs and comments.

Sylwia said...

What more can I say? Bravo. I wish there will be a day when I show something half good as your pottery. If you know what I mean.

Peter said...

Hi Sylwia, I keep thinking of that lovely bowl that you did that is on your blog. I think you already do good things, but thank you for your kind thoughts.

rwhendrix said...

These are some beautiful pots indeed. I actally like the copper glazed pot that stayed green instead of red. Did you ever discover what was holding your kiln temperature down that you fought to get to climb too? was it just damp wood?

Peter said...

Hi Richard,
Probably one of my main problems with getting the kiln to temperature is a rather poor selection of wood. I burn just about anything I can get that is dry. I also may have packed too much work into the kiln. I've been thinking more and more that I should go for a looser pack and less kiln shelves. I think that would also help the kiln fire more evenly. When I first made the kiln, I had a different arrangement of small kiln shelves over two side by side fireboxes. Whilst the stacking was a hassle as there were too many props and the small shelves didn't hold enough work, the circulation of fire through the kiln was better and it got to temperature more easily and the temperature in the chamber was more even. I'll try to arrange things a bit better next time I fire. Always things to improve on and try with this, which makes it more interesting!

Best Wishes,
P.