Kiln Opening: The Anagama Woodfired Kiln Gives Birth

Earlier we fired the anagama kiln. Now we open it.

A kiln takes a while to heat up, and even longer to cool down. Waiting, waiting, patience; opening too early can cause thermal shock and break the pots within, opening too late – there’s no too late. There’s just how long you can look at the wrapped presents under the tree without peeking.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

The kiln, the kiln it waited for a week and a half. We waited for a week and a half.

Now we waited no longer.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

The door sealed by bricks, a wall a brick-and-a-half wide, all there is to keep us separated from the heat when the fire was 1350˙C, and from the pots when the inner temperature was air temperature.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

The alarm set for showtime.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

Slowly the wall came down, and the light came on the pots. And we can see: what can we see?

This firing went much better than my previous firing at this kiln, that we knew even during the firing. Sure there were issues: the kiln was packed too tightly. But the kiln shelves held, the fire went on longer and (about) as hot as was planned. But what will be the results?

On opening, on first peek: looks good. Some pots at the bottom of the front stack were broken, likely hit by wood sticks as they were put into the kiln. Nevermind; this is in a way to be expected, an unfortunate byproduct of the kiln’s design. The kiln design is old, millenia old, and it has its pros and cons.

But the cups: the gloss from the glaze, there’s a gloss from the glaze. The natural glaze, that is: the wood melted and in the air and landed on the pots and cooled and solidified on the pots.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

As a fire brigade. One/two people inside the kiln, pulling pots off the shelves and passing them onto the line. Each person in the line: excited about the pots that they hold, excited for the pots to come, passing them all on to the next person in the line: excited about the pots that they hold, excited for the pots to come.

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

And sometimes a surprise. This bug, this bug came out of the kiln. No, not landed on a pot as we were taking it out; landed on a pot as it went into the kiln. And some pots didn’t survive the firing and cooling but this guy did. He came out still as night yet give him a minute we gave him a minute: he flipped himself, he flew off. After wood ash and over 1000˙C for over days.

 

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

Kiln opening of the Janjagama Anagama Woodfired Kiln Erik Haugsby Pottery

The weather as good as the results.

Anagama, Again: Firing the Janjagama Woodfired Pottery Kiln, July, 2017.

I make my pottery in Vienna my home, and others make their pottery in their home, and sometimes our paths cross. This a time, this a crossing: my second firing of the anagama woodfired kiln at Atelje Janja Gora, Croatia. I the American living in Austria, firing with others from Slovenia, Croatia, and Taiwan.

(photos from the previous firing here)

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

We fired for a total of 39 hours, and reached a max of 1293°C. The kiln was packed tightly, very tightly, making it difficult to attain and maintain these highest temperatures. Whereas with other firings it was possible to go from 1200° to 1350°+ without so much as looking at the kiln (perhaps not looking was the trick), with this one we struggled for tens of hours to get just 100 degrees higher. But in a way, better: a longer firing leads to more wood ash building up on the pots, and beautiful wood ash is the hallmark of an anagama kiln.

Not a single piece glazed (I learned from my mistakes last time I fired at this kiln), the clay will develop a color and texture all its own from the path the fire weaves through the kiln. Fire is wood ash, physical objects burning themselves away, and as it lands on pots it sticks to the pots and melts to the pots, yes please.

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Anja Slapnicar, at the left, has fired this kiln some 10 times. Branko Šupica, at right, built the kiln in 2013.

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Liank Wu here, a Taiwanese potter under whom Anja spent some time working. Wu himself works under (for 19 years, he says) the potter Lin Jui-Hwa: the potter who set the Guinness world record for highest temperature in a wood-fired kiln i.e. 1563°C. Sure there are some potters who fire to such temperatures without needing a Guinness team (sometimes without needing a pyrometer), Kumano Kuroemon comes to mind, but still.

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Inside that kiln there is 1200+ degrees C and a meter or two away you’re drinking water trying to stay slightly cooler. The kiln’s walls are thick, thick helps insulate in a way but also maintains temperature. Once it starts getting hot, it starts staying hot. Cooling down takes a good 7 days, from 1200 to 20ish.

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

Black smoke, reduction, when the kiln’s atmosphere is deprived of oxygen. Fire needs oxygen to breath, so given said dearth it starts to suck it from the pots: the oxides in the glaze, and in the body. This causes deliciously irreversible changes in both glaze and body: a glaze what with enough oxygen will look glossy jade green in reduction turns a blood red, for example.

Kilns often move between oxidation, saturated with oxygen, and reduction; a good firer knows 1. which atmosphere is appropriate for the works inside 2. how to get that atmosphere 3. when to get that atmosphere. Some glazes need reduction, some glazes need capital-R Reduction, some clay bodies need reduction, some need capital-R reduction; sometimes, like this time where we used no glazes on the pots, reduction happens but it isn’t a goal.

Erik Haugsby Pottery firing the "Janjagama" Anagama kiln at Atelje Janja Gora

And it’s done. The kiln signed and sealed, the pieces waiting till the opening and the delivery.

Making my own ceramic glazes: glaze workshop with Markus Böhm at the International Ceramics Studio

Glaze, glass, clothes for pots, clothes make the man.

Like clay, glazes are in theory pretty straightforward: a stone that, when heated up high enough, melts into a glass. The simplest would be using 100% silica – sand – but silica melts only at 1400°C, and most pottery is fired between 1000 and 1300°C. So we need to add something to the silica to make it melt earlier.

So oh my how many different ways there are to make (and to fail at making) a glaze. 

You can buy pre-mixed glazes from suppliers, it’ll be pure and predictable but then you’re paying for their work – you don’t know exactly what’s in the glaze – you can’t modify it for your purposes – it’s usually rather boring.

You can mix your own glazes from raw ingredients, it’ll be yours but then all the successes or failures fall on you. Does it stick to the pot, or flake off? Is it completely melted, or still a little rough? Does it have blisters or pinholes, or is it smooth across? Are those cracks supposed to be there? Does it scratch when you’re cutting through that steak? Oh, and: is it the right color?

So I’m trying to get better. So last month I went off to spend a week learning about glazes. The teacher, Markus Böhm, is if anything interested in formulating glazes through empirical methods. Way back when the Japanese apprentices might learn “take one scoop of this, two of that, heat it up until the fire burns this&/that color, and it’ll turn out”. That did work, and still works, but those there potters are building on centuries and generations of experience. Chemical analyses and computer programs can make the learning process a bit faster.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

So we (six of us in total, a mix of hobbyists and career potters, all wanting to make a better glaze needn’t be said) used chemical analyses and computer programs and from about 6 base ingredients made over 1.400 different variations of ceramic glazes. A little bit more of this ingredient, or a little bit more of that, and you’ll get a range of results from the utterly unusable to the cosmic.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

The whole thing happened at the International Ceramics Studio, this delightful former porcelain factory smack dab in the middle of Kecskemét, Hungary that’s been turned into a state-then-city-run base for potters of all walks to come and make and fire their work.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

And so we made and glazed and fired our work. 2 days of theory about glazes, 2 days of practice making the glazes, 2 days to fire and open the kiln.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

And then when we opened the kiln: results. What we learned about glazes, the mixtures we made, the ones we thought would succeed or fail; all laid bare before us.

Glaze Workshop with Markus Böhm at the International Ceramics Studio, Kecskemét, Hungary.

I came away with knowledge, firstly, but also a few cups. Some of them are up for sale at my Etsy.

Erik Haugsby Yunomi Cup Tenmoku Woodfired Handmade Pottery Ceramics

Erik Haugsby Yunomi Cup Wood ash Woodfired Handmade Pottery CeramicsErik Haugsby Tea Cup Celadon Woodfired Handmade Pottery Ceramicssby Tea Cup Celadon Handmade Pottery Ceramics

The Sasukenei Woodfired Kiln at Hendrik Schöne’s Pottery

My third wood firing. Third time, third kiln.

If you ask a question in pottery, invariably the answer is “it depends”. The clay body, the throwing style, the temperature and humidity of the air, how long you’ve waited, the speed and temperature of the first firing, the ingredients in the glaze, the glaze recipe, the glaze thickness, the fuel used for the second firing, the speed and temperature of the second firing, the placement in the kiln, the speed of the cooling of the second firing, and. And. And.

New kilns, new glazes, new unknowns.

Relaxing as the kiln burns. The countrysides ajoining Hendrik Schöne's pottery are a mixture of farmland, wind power, forest, and industry.

Filling the kiln with wood: each few minutes, a few sticks branches entire tree trunks.

This time around I went off to Saxony, Germany, to fire with Hendrik Schöne. He’s been potting for longer than I’ve been alive, has been building kilns for a decade, and lives in a former water mill off in the borderlands of Germany-Poland-Czech where one can stand in one spot and see see solar/wind power-coal power-tourist restaurants atop a hill (respectively).

Firing the Sasukenei kiln at night. At left is the chimney, more than 6 meters tall. The red glow at the top is not fire, but rather a reflection of the fire that flows through the kiln and up out the chimney.

For me, a special treat was the “hikidashi”, a Japanese word which literally means “pulled-out.” In the ceramic sense, it pots which pulled from the kiln when blisteringly hot (1300 degrees Celsius) and cooled in a bucket of water.

This treatment, combined with a glaze that’s 50% iron oxide and 50% wood ash endows them with a luscious matte black surface. When you’re lucky.

In this kiln there are only three spyholes which are the of the right size and position for hikidashi, so when you’re lucky a max of 3-6 hikidashi pieces come from each firing. Lucky me, both of my pieces came out; the other four were less fortunate.

Two cups glazed with a high-iron (50% iron oxide, 50% wood ash) glaze, as viewed through a small spyhole at the rear of the woodfired kiln. These are intended for 'hikidashi', which means that they will be pulled from the kiln when red hot (1300 degrees Celsius) and cooled in a bucket of water. This treatment endows them with a luscious matte black surface.

The hikidashi cup, after being pulled from the kiln whilst red-hot and now ready for use.

One day to chop the wood (12 cubic meters in all).

Two days to fill the kiln.

Three days to fire the kiln.

Four days to cool the kiln.

One day to open the kiln.

There are ways you can control the process. You do have a hand in choosing your materials, and in shaping your materials, and in feeding the fire. Yet, it’s also relaxing and oh so stressful to give yourself to the kiln. To let the kiln give you something. To let pots be born, not be made. At no point in pottery can you change the outcome: you can’t go back, you can’t go sideways, you can only go forward. To accept the failed pots, to celebrate the successes, to make it better next time. To the next time.

Wood-fired pottery in the Janjagama Anagama kiln: October, 2016

Firing pottery is the last step of the making process, where all the gestures and decisions and movements and accidents are solidified. No going back, no going sideways, whatever comes out is. Is, just is.

Firing is effectively just heating the pots up, and letting them cool down. There are a few different ways that you can do this, with today the most popular being using electricity (think: high-powered toaster oven), gas, and wood. I use an electric kiln in my studio. My first experience with wood-fired pottery was in October, 2016, and here are some notes from back then:

Janagama Wood-Fired Kiln Erik Haugsby Pottery

I’ve met a few potters around where I live, and one of them lead me to a kiln at a place called Atelje Janja Gora, a house-cum-pottery in the hill-lands of central Croatia. It’s run by a husband-and-wife of Branko Šupica and Danijela Pešut who hold occasional workshops and firings. 10 of us got together with our pots and plates and cups and bowls and vases and shape and love, hoped for the best and came out with not-the-worst.

This kiln is an “anagama”, an ancient kiln design (first built some 2000, 3000 years ago) that spread across Korea and Japan and which let them fire with higher temperatures and more consistent results than western potters achieved in the 1500s. It’s essentially a tunnel: the wood is put in the front, it burns through the chamber and melted ash lands on the pots, and then the heat exists through the rear chimney.

Janagama Wood-Fired Kiln Erik Haugsby Pottery

This kiln was built in 2013, with help by the Belgian kiln-builder Lou Smedts, and it’s been fired about twice a year since then. The last firing went to a pyrometer reading of 1300c in 12 hours and although cone 11 was down in the front the back barely hit 1100c. Their goal this time was to get up to temperature and hold it till some 50-60 hours elapsed.

My first wood firing ever. My first (since university) cone 10 firing, first (since university) reduction firing.

There were a few surprises along the way, largely due to my misunderstanding. I thought it would be a salt firing, so I read up and glazed up appropriately. Turns out they used 1 kg of salt primarily for sealing up the surfaces, as opposed to inducing effects. And nobody else glazed because they were hoping for major ash accumulation.

Janagama Wood-Fired Kiln Erik Haugsby Pottery

It follows that they planned for a 60-ish hour firing to cone 11+. About 22 hours in, about 4 hours after reaching 1300c and some 8 hours after reaching 1200c, we took a peek inside and saw one of the kiln shelves in the front stack bending badly. We sealed the kiln up right then and there: better to not get so much ash than to risk losing the first if not all 3 stacks.

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery

So, it sat and cooled five days. The pyrometer still read 88c on the morning of the opening day. We opened it.

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery

I had lots of issues with my glazes/glazing. All glazes were mixed from recipes using powders purchased from my local pottery supply. I’d never used any of them before. But some of the stuff worked out. Only one piece actually broke and that’s because during stoking it got pushed up against the wall and melted together.

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery

Janagama Wood-Fired Kiln Erik Haugsby Pottery