Here is an example from the sixth firing, one of the most beautiful firings and the most disastrous due to multi-level shelf collapsing.

  Full size image.

This piece was just back of the firebox — a band of black koge can be seen in the front of the image.  The rest of the images from the sixth firing are posted on this site, but the location is pretty buried — I should add them to the photogallery.

Anyway, Furutani’s kiln design has no trouble melting sand.  In fact, it is beginning to dawn on me that I will have to work harder to keep firing temperatures down a bit, as I believe I’ve been overfiring to some degree.

You’ll see the anagama being fed, make a tiny steam tornado, and breathe fire. When the fire is pouring out the chimney, it’s like a river of bright water rushing over rapids. I could watch that almost endlessly.

One part may need a little explaining: about midway through the video, and at about the hottest temperature during the firing, I take out a “pull”. A “pull” is a piece specifically made to be pulled from the kiln so that the amount of glaze build-up can be evaluated. Pulls are crucial because the end of the anagama firing is determined by how well the pieces have developed ash glaze. Temperature is obviously a factor, but cones typically flatten out by the end of the first day of the three to four day wood firing period — where cones really fall down, is that they say nothing about the level of glaze build-up. By loading a few pulls, the glaze level can be checked quite thoroughly.

Without further ado, here are links to the video. Note: quicktime format; both are the same content but the 20mb clip is better quality, though a somewhat hefty download. I’d suggest doing a “save as” on the link as it might take five minutes or so even with a broadband connection.

~6mb video clip, really low quality

~20mb video clip, acceptable quality

Frank is a character. He is an attorney from British Columbia, Canada, and a very good potter to boot. The piece Frank gave me from the last firing is a lovely thrown and altered porcelain bowl, light and balanced without feeling like it would break if hit by sunlight.

Here are some pictures of the bowl I’m speaking about (clicking any picture opens a medium sized copy (1024×768) in a separate window):

I believe the brown stripes are due to glaze dripping off the ceiling. Oddly though, there is one inside the bowl and outside under the rim. I know Frank glazed some of pieces with a shino, but I’m pretty confident the brown stripes are unrelated. It takes no explanation to understand how the drip inside the bowl could have appeared there. The glaze drip under the rim mystified me for a time — glaze drips don’t fall sideways (and if they did, one might wish to consider dampering the draft a bit to prevent inordinate heat loss).

Although this is one of the few pieces that survived the firing, it did not pass through unscathed. There is a contact scar on the rim coupled with a large area on the foot that was bonded to the kiln shelf quite well. The orientation of the rim scar corresponds perfectly with the large foot scar. Plainly, one drip fell into the bowl. Then the shelf failure occured, the bowl tipped onto its side, and a second drip fell on the top side of the pot in its new position.

This bowl, besides being a wonderful piece in its own right, is telling me an important story. It is telling me that the kiln was hot enough and sticky enough to drip glaze over an extended period of time. It’s telling me to shorten the duration I keep the kiln at its peak temperature. This doesn’t necessarily mean I should shorten the firing, it just means I need to hold off on turning the inside of the kiln into a demons’ playground. That should help keep more glaze on the pieces and allow less to drool off onto the shelves.

I’m very happy to have this bowl, not only for what it is, but for the lessons fused with its form.

Enough about that though, this is supposed to be about Frank. First, here is another piece he gave me (click pics for larger view):

This little tea bowl is from a gas kiln Frank built and fires to cone 10 with a weed burner. He says it roars like a jet plane at the peak of firing — having some experience with weed burners, I don’t doubt him at all. I love that he built his own kiln rather than having simply bought one. That kind of self-sufficiency is something I admire. Nor is Frank afraid to get dirty — he’s delving into the geology of pottery, digging up local rocks and clays and compounding his own clays, slips, and glazes. This isn’t to say he doesn’t use commercial mineral products, but having myself spent a fair amount of time digging — I respect the labor involved.

One last little tidbit. Frank has met or is familiar with the work of many many potters. I started to get embarrassed at my lack of knowledge about practically anybody. I tend to be reclusive, but I also realize I need to get out and meet people and see other works — without that exposure, I’m limiting myself.

I hope the last disastrous firing doesn’t keep Frank from stoking again — he’s a welcome addition to the stoking crew.

First however, let me say that for me, a firing is more than the short period of burning wood in the anagama. It spans several segments — making, preparing, burning, waiting, opening, and reorganizing. In my mind, even though I won’t be loading the kiln again until September, the 7th firing begins tomorrow.

Making

I have great hopes during the time of making and much curiosity about clay and the way it responds to touch, or the way it swirls under my fingers on the wheel, or how it cracks when I pinch it hard. Visions of pots precede my sleep and interfere with my waking duties. I have a sense of hope, tempered by a sense of my actual abilities. The period of making is like late summer — an easy time with fruit and berries everywhere for the plucking. Carefree, careless, and fun. A time for dreams, experiments, and playing. Such vacations never last — for me, about four weeks before the pots go in the kiln is about the time I realize how far behind I am in my preparations.

I must plan more adroitly, even when life seems easy and those deadlines so far away.

Preparation

The time of preparation is quite uncomfortable. With a dawning realization that I have much to do and less time to do it in than I need, I become tense and preoccupied. I begin to worry about every little detail — do I have enough wood, do I have good enough wood, is the wood going to make ugly glaze? Do I have enough pottery, is it good enough to even stick in the kiln, will it collect any shizenyu? Do I have the ability to fire at all? Will I be able to sleep? Can I get the time off? I perserverate on many details, arguing with myself, wondering what to do. I feel an overriding sense of ineptitude and insecurity.

The last week before the firing is the worst — it’s a typhoon of small details and errands culminating in the actual loading. Loading the kiln is hard beyond I ever imagined it would be. It’s mentally challenging and physically excruciating. I don’t know how to make these words describe the difficulty. It’s half a day laying on brick corners in scrunched up positions reaching into the most awkward positions — and it’s harder than that even hints at.

Burning

Quiet stillness — a fire is lit and everything slows to a relaxed pace. Burning wood is a sort of silence. If I sleep enough, it’s the easiest part. I’m still working on the self-discipline to leave the kiln’s side and go to bed — aside from that fault of mine, sticking wood in the kiln for several days is like living in a world without time. At night, all alone, listening to the fire, or frogs singing in the field, or rain and wind roaring against the metal roof of the kiln shed, I feel outside of time — outside the world. I feel silent.

Waiting

All too soon, the stoking period ends. It is replaced first by pure exhaustion — when I fell asleep after closing up the kiln this last time — my legs felt like they were laughing — to just stretch out on the floor of my studio lounge was a delightful sensation. Quite literally, I fell asleep giggling as my legs expressed their pleasure in their lightened burden.

Following exhaustion, comes a period of … grogginess? It’s a time where I have to try to fit back into the world and start thinking in that other sense again. It’s a hard adjustment to go from a timeless world punctuated by only a handful of events — stoke, make coffee, eat simple stuff, nap, stoke — to one set rigidly against the clock, where deadlines are arbitrarily decided as opposed to dictated by natural conditions. As added insult, waiting to open the kiln is painful — the test is over, the work is graded, and the prof is torturing me by lecturing the class before handing out the grades. Whether the firing is good or bad is already decided, and I can’t even find out till long after the fact.

Opening

Opening day — I’ve had my most bitter moments on opening day — and some of my sweetest. I’ve stood there smashing piece after piece after piece because of the utter failure of my technique. I’ve stood there admiring glaze that formed as if by some magical underground force — the kiln god’s hand obvious in the mysterious complexity of surface and sight.

Opening day was a week ago (a disaster but a good one nonetheless). I have broken nothing on purpose. The 6th firing is settling about me now — around the kiln, in the yard, all over the shelves and counters of the studio, as well as in my mind. I’m still taking it in … but I’ve also begun my cleanup/reorganization phase. It isn’t clear to me whether cleanup marks the end of the last firing, or the beginning of the next. I suppose it is mostly about transition.

Tomorrow I begin making pieces. Although I don’t know that the 6th firing has fully ended yet, there’s no question in my mind that the 7th firing’s time of making begins tomorrow.

I’ll get a handful of usuable pieces out of this firing — almost everything is a total loss. I’m “so stoked” though — truly, I couldn’t be happier. The glaze is amazing despite being a bit overfired (too much of it drooled off the work), but I finally think I have a handle on the appropriate air/fuel mixture and a reasonable idea of how much empty space the anagama requires. The fire itself needs room to expand or it simply takes all its good stuff out the chimney. Plus, I have a good plan for the next firing for improved effects. It’s taken three years of “doing it wrong” to get here, but I think progress will accelerate from this point on. That’s why I’m so satisified with this disaster.

Without further ado then, check out the pictures! Notes:

• These are fresh out of the kiln — no grinding has been done on them yet.
• There are lots of scars due to the extensive collapsing.
• This page is just a rough draft of what I’ll eventually put in my website.
• Small pics link to medium sized pictures 1024 pixels wide.
• No comments on the pics except that my wadding based clay exceded my expecations — look for the very glassy blue/green piece w/ speckles. The body needs some tweaking, but it’s sweet! Of course, no real fire color on it because of the massive amount of feldspar sand I dumped in it — still, never ignore serendipity.

Starting at the end, here is a sunrise shot of Mt. Baker taken a short time after the firing ended. No firing record would be complete without reference to our local volcano.

And a little north of Mt. Baker some pretty gold:

This is what I look like at 5 or 6 am, 100+ hours from my last shower:

Andrea showed up unexpectedly at about midnight the last night of the firing. She said she wanted to stoke for a little while — I said “sure” (she’s stoked before). At one point she said she really ought to get going, I said “do you mind if just take a 5 minute nap” — sitting on the bench on the left side of the kiln pit, back against a cinder block wall, I then slept like a log till 4 am when I awoke with terrible leg and butt cramps. Andrea Saved the Day — there’s no way I could have stoked all night the last night.

Pull from the first day (18 hours wood):

Pull from the second day (42 hours wood):

Kiln Demons basking in the chimney’s warmth:

An overall view of the pit. Silver supervising:

Preheating with gas. See how wet the kiln is to start? The base bricks didn’t fully dry out till the third day of wood firing:

Anagama chimney shot:

And WOO-HOO! — one more day gone by and no peeking. This note is for Frank. ;-)

I like this picture of the “cat warmer”, AKA: anagama kiln, better than the one I posted earlier. This is from early in the firing. Late in the firing, the cats moved mostly to the chimney area. If crossing the kiln, they did it at a fast trot by the time the kiln was at temperature.

It barely rained during the firing so the cats spent a lot of time sprawled out on the platform behind the chimney. It’s there so I can mess with the chimney during firing or place/remove the cap tile brick. I tried to catch them not looking at the camera to avoid the demon eyes issue … I wonder why I failed to think about turning off the sound in the camera — they always look when the focus chime goes off. Sleepiness impairs brain function!

OK, enough about the cats, that isn’t what people look at anagama sites for. Here’s the pull from about 67 hours into the wood firing portion (note: this time frame includes the day it takes to get to temperature). The firing continued for an additional 30 hours but I had run out of pulls (I broke one accidentally). I should note that these are made of three clays — porcelain and two stonwares. I didn’t slip and score, just pounded them into a loaf and cut slabs — the crack separates along a porcelain/stoneware seam.

And last for now, here is a peek at the damage done:

I also understand the kiln monitor issue. The probes are encapsulated with glass. This either insulated the probes or affected they’re sensitivity in some other way. This is the last time I let a number on the monitor influence my thoughts. I still like to have the monitor, because I can correlate what I see from the chimney and hear from the kiln with whether the temperature is rising or falling, but achieving any particular number is completely irrelevant.

Talk about hot too — the shelves look like lasagna noodles, thin pieces unimaginably warped, as if they melted over their wadding. I suspect a 25% retrieval rate will be generous. Despite the obvious failures in these regards I am ecstatic. I wasn’t positive I could fire this kiln to a glassy result.

Last firing, I made the firebox area a little bigger and results improved from firings 2-4: the 5th firing had decent glaze and a lot less black crud than those intermediate firings. In this firing, I made the firebox bigger still (too big) and it got even better. Obviously, the sweet spot in this kiln is somewhere in the middle and I’ll be able to hit it next time. Now I can focus on other issues.

Stacking shelves is difficult beyond belief in this kiln. The obvious solution is to make stuff that fits the kiln better and doesn’t need shelves. I think in the next firing I’ll make only two rows of shelves — the rest will be pieces made to fit the size and shape of the kiln at the various levels. I already have some ideas for things to go there and I’m very excited. Can I wait till September?

As for a kiln monitor to use till I’ve trained my eyes and ears to be all I need, I think I’ve thought of the perfect solution. I’ll make a thick rectangular slab shaped piece with a built in prop so it can be stood on edge easily. At the top, I’ll put in some gravel size feldspar chunks. When those melt, I’ll have glaze. More pulls too. I suppose I’ll have to have a center shelf right behind the firebox to raise these test pieces above the coal bed — perhaps a pillar of bricks would work best. A 9″ square pillar 18″ high will not fall over.

Anyway, now for the really hard part. Cleaning up the kiln site, and even worse, waiting for the kiln to cool! Maybe I’ll go pitfire something in the hole I dug getting dirt for the ceiling.

I’m hoping if I write a bit, I’ll be able to stay awake till dawn. At this point, it isn’t clear to me that I’ll make it. Exhaustion is catching up with me. OK, take a deep breath. This is fun, an adventure. The sort of thing that makes good stories later. I enjoy this. The longer I stay up, the better bed will feel.

So I need some topic — how about “worrying”. I’m a worry wart (wort?). There isn’t anything I can’t worry about. A glass half empty guy and I’m noticing that the glass is cracked and leaking.

So today I gathered up all the bricks I could find. I don’t have a ton of leftovers. I came up with 24 bricks though, enough for four courses at the top of the chimney. So I raised the chimney 10 inches this afternoon. Here’s what I was thinking — the wind that I’m missing helps increase the draft. If there is no wind, increase the chimney.

So I do that (as if 10″ on 96″ chimney will have a significant impact) and immediately start worrying about black crud on the pottery. Here’s the worry:

I’ve been thinking about building a wood fired bathtub out here. FYI, my last shower was Tuesday, so — yeah, it would be nice to be able to take a bath. I won’t go into the plans but it involves a natural siphon, metal cow trough, old stove, and some piping. Anyway, in my research I ran across some wood stove discussion on the net in which it was mentioned that controling the burn rate of a stove by the air vents instead of a damper causes a sooty chimney. Well — this kiln has no damper, the air vents control the burn. So I was thinking that may be the cause of my black crud. Seems the same principles would apply.

So, to come back from that tangent, I no sooner had 10″ more chimney when it hit me — that effectively makes my air inlet smaller and there might be soot buildup. I’ve been concerned about that for the last few hours. I took off one course a little while ago — I’ll probably take more off later.

All this because the kiln monitor doesn’t want to break 44 mV reliably, and instead hangs out at 42-43 mV and I want to go to 50. Drat! But make that a real swear word.

On the other hand, there are two loose bricks on the bottom side of the upper fire mouth — the stoke hole. They’re constantly being knocked in a little and then I pull them back with the hook on the pole if I remember. The tips of these bricks have become glazed. If I can glaze bricks that have air coming in over them from the edges around the door to the firemouth — things should be OK inside the kiln. Really. I tell myself this but I still worry.

Well, I haven’t checked my email in two days and I’m worried about what disaster will have happened at work, so I better do that now. Besides, I need to go fill the wheelbarrow again. At least I feel “awaker”.

I’m trying to think of ways to stay awake, except I keep daydreaming about sleeping. One way is to get one armload of wood at a time from the shed instead of a wheelbarrow load. It’s much easier to stay awake when standing. I made some tea earlier because I knew the whistle would wake me if I dozed. I didn’t really want the tea.

I’ve been listening to This American Life, the Habeas Schmabeas episode is quite the listen. But now the stories aren’t keeping me awake — they are weaving themselves into dreams I have. So I decided to try to write an entry. It’s working and I feel much more alert.

I pulled the third pull (FN 1) from the kiln last night. Actually, I tried to pull the third but it got stuck and the loop for the pole broke. So I pulled out #4 — the last one I have. The glaze is very good (YEAH — relief arrived, I’ll just write this and go to bed — SO HAPPY). Even on the stoneware the glaze is thick and glassy. Porcelain never has issues w/ glassy glaze but my stonewares haven’t been doing so well.

It’s confusing though because the kiln monitor is showing a lower temperature than in other firings. Raising the temperature has been hard this time. First, there is no wind. I mean none. Fire shoots straight up from the chimney. I noticed the few times a breeze blew through that the temperature rose (gosh — feels like I already wrote about this). It’s usually blowing like the devil whenever I fire.

Secondly, I may have made a stacking error. Thinking back to the first firing, there was a lot of stuff tumble stacked in the kiln (FN 2). All us stokers being inexperienced, we smashed that stuff up pretty quickly. However, for the stuff that survived, the glaze was simply gorgeous. In subsequent firings I stacked closer and closer to the firebox and things got progressively worse and worse. Last firing, I backed off a bit and things got better. This firing I backed off more but maybe too much. Perhaps there isn’t enough mass in the kiln.

And right now, it’s pouring rain. Steam is rising again meaning water is cooling off all that soil I warmed. Did I already mention the curiosity with pyrometer? It 41 mV after about a day, day and half of wood — I can’t recall exactly. Then stuck at about 40. Early on, the fire was easy to look at: orange. After a day, the fire was painfully bright to look at without welding goggles.

A word to the wise — sleepy stokers suck. Tony’s getting the temperature back up, which is quite the relief. Another word, writing is quite a good way to wake up. I finally feel alert and awake — just in time for bed.

Anyway, last comment — the pulls make all the difference. Cones don’t work in this kiln (they melt early on), and type K thermocouples are notoriously inaccurate. But a pull doesn’t lie to you. If it’s glossy and coated with glaze, that’s what is going on. If it is rough and dry, that’s what is going on.

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1. A pull is just a piece pulled from the hot kiln. My pulls for this firing are like small baskets about 1×3 inches with a tall loop in the center. They’re made of the three clays I used most — sort of neopolitan.

2. Tumble stacking is a suggestion people often make to me. But it just doesn’t work in this kiln because the pieces get so heavily coated with glaze — it just results in glued together gobs of pots.