First Peaches of the Season

Janine and I set up the plastic pipe hoops and installed the netting over the peach tress in the stone fruit orchard 3 weeks ago as the fruit started to appear. These early peach trees develop their fruit so quickly. They swell from buds in no time flat.

We knew that it was time to cover them when we saw parrots in the trees starting to eat the tiny young green fruit. It’s been so dry here as the drought drags on. Actually I don’t believe that it is a drought – an unusual event, that is just bad luck, as the politicians would have us believe. No! I believe that this is the new normal for us in this continuously developing global heating crisis. The rain fall pattern has been changing and our share of the rain has been steadily decreasing ever since we settled here 43 years ago.

We used to be able to get by here in this place with the water that we collected in our dams. We used to get terrific, short, intense rain storms, that would drop 20 to 25 mm. of water in an hour or two. This sudden flow of water had no time to soak into the soil and just flooded down the road in the gutters and then down the ditches that we had dug to harvest that flow, and into our dams. A good storm like that gave us sufficient water to get us through the best part of summer. We don’t get those storms any more, not for a decade or more now. In the 70’s we could get two or three of those storms in the summer months. Sadly no longer.

I have been a long-term subscriber to ‘NewScientist’ magazine, published out of the UK, but we now have our own branch here in Australia these days, with an Australian edition, so the Australian content has been increasing steadily. Over the 45 years that I have been a subscriber and reading the research published on our increasing emissions of carbon into the atmosphere. I’ve seen the steady increase in certainty in the science behind our understanding of the evolving crisis. I’ve also seen the strenuous denials from the carbon intensive industries lobby, building from straight out denial that the earth is warming at all, to now admitting that there is warming, but it is nothing to do with carbon in the atmosphere. All the denial and fake news claims, even the spurious pseudo scientific fake ‘research’ sponsored by the carbon lobby, is straight out of the cigarette industry playbook.

We are drying out here, slowly but surely. We have some peaches on the early peach trees, but there are no apples and just a few pears, as there wasn’t enough cold nights over winter to build up sufficient ‘winter chill hours’ that the fruit trees require to be able to ‘set’ fruit. We did get a ‘set’ of cherries on the trees, but with the exceptionally dry conditions, it has driven the kangaroos up out of the dense bush in the gullies up into our back yard and right up to the house in search of food. They have begun eating the cherry trees lower branches and the parrots have taken all the fruit while it was still green and hard. I’ve never seen that before. These wild animals are obviously very hungry.

In some ways it’s OK, as now we don’t have to worry about keeping the water up to the orchard, as we are very low in water storage. All 4 dams are close to empty. I need to get the portable petrol pump out and pump all the 3 other dams dry and locate all the remaining water into just one dam to minimise surface area and evaporation. We may need that water to fight fires over the coming summer.

At the moment we are OK, we are managing to water the vegetables and the few peaches from our rain water storage tanks, but this is a finite resource. We are already half way through our main large water tank, and we are still in spring! We still have one more large water tank full. That is our reserve supply. We’ll just have to wait and see how things pan out.

With almost every roof on our property already fitted up with guttering and a rain water tank, it’s hard to imagine how we can increase our storage in the short term. We can only double up on our storage tanks to catch the overflow from the original tanks, should there be a big storm – which there will be one day, bit that isn’t going to be any help just now.

For the time being, we have some early peaches to console us and reward us for our efforts.

New Sericite Clay Samples

I was recently in China doing some research. I have written a little bit about that, intermittently, in the last month or so. While I was there, I arranged to get my hands on some new and different sericite samples. These have now just arrived here last week and I have done my first tests with them.

I now have 4 different Chinese sericites to compare.

Although it isn’t immediately obvious from the image above. If you look closely, there are 4 different colours of rock samples from top to bottom, white, cream, grey and pale buff. They all look more or less white, but they each have various tints or shades of colour to their whiteness. They all do have one big thing in common. They all throw badly, the palest ones being the least plastic and most difficult. They feel a lot like my local Mittagong porcelain stone, only better behaved.

I felt like I’d gone all the way around the world and come home again when I threw these tests. They felt so familiar.

I’m really looking forward to seeing the results fired. I had a bit of trouble with the usual shrinkage and drying cracking problems, but I did get some of them through successfully. But I lost quite a few. Still, nothing that I’m not used to, and I’m getting good at recycling the turnings and failures.

I almost filled the tray on my old wooden kick wheel with turnings after trimming just 12 small bowls. I must be removing at least half of the weight of the original material to get them thin enough to look and feel like porcelain. I aim for 2mm at the rim and 3 mm lower down, graduating 5mm at the foot. This tapered wall thickness allows the best translucency at the rim and higher up the pot, while retaining sufficient strength to hold the pot up against gravity while it sits at 1300oC in the kin to develop enough glass in the body to be come translucent.

If I’ve done it right, the whole finished, fired, ceramic mass, has the correct quantity of primary and secondary mullite crystals to glue it all together, while becoming glassy enough to allow plenty of light to pass through.

Too glassy and/or too thin and it slumps. Too thick or not fired high enough and it stands up straight, but isn’t very translucent. It’s a bit of a fine line to tread.

not too bad.

As I sit and grind away at this damp, ground-up rock dust with my tungsten carbide tools, I realise that I’m truely happy doing just this. There is a gusty wind outside, but I’m in here sitting in the sun and I don’t want for anything more at this moment. This is fun. I can’t wait to get them into the kiln.

It has all the promise of something special about to happen.

I love that.

High hopes are not enough

After I had such a terrible firing a couple of weeks ago. I got stuck in and remade all the work. I’ve filled the shelves and had 2 solar fired biscuit firings and I am almost ready for the third. Then I can pack the wood fired kiln again. Hopefully this time with more success.

I had slaked down all the turnings from the last work session and made half of this work from the recycled sericite bodies. I have made test batches of 5 different sericite this time round. I have 2 Chinese minerals, 1 Korean, one English and one Australian in this batch. Although strictly speaking, the local one is a complex mixture of Illite, kaolinite, quartz and felspar.

I’m always looking for something that I don’t know, so the search is a bit difficult as I’m working semi-blind. I know more or less what I want and how to achieve it. After all, I have been doing this research for the past 40 years and more. But getting what I consider excellent results is always elusive and difficult. It doesn’t help when the kiln shelves break and collapse… Still, I’m over that and all the new work is made and drying. I’m just turning the last of the throwing today.

Sericite is funny stuff. It isn’t plastic like other clays, it’s quite short in most cases and has to be coaxed along to get any height in the form. I learnt to throw the inside of the form as I want it, leaving a thick wall to retain the form without it squatting. I then have to turn quite a bit of material off the outside to realise the finished form from the thick lump at the base.

Although sericite isn’t plastic, it still shrinks quite a lot and has a terrible tendency to crack in drying where it is thick. I have developed a few techniques to cope with theses peculiarities. I’ve learn’t to throw everything on batts, as lifting the pot with my fingers causes a memory distortion in the body that shows up later in drying. I’ve learn to ‘polish’ the out side of the clay after I have finished throwing, to seal any possible defects or weak spots that might start a crack during the early stages of drying and stiffening. I have also learnt to turn the bases in stages. Thinning out the clay as soon as it is stiff enough. This stuff can’t be turned like ‘normal’ clay based bodies. It has to be very firm, almost dry to get a smooth finish. If turned too early, it chips and tears, making an awful mess of the fine surface. It’s a bit like cutting soft goats cheese, it just tears.

Trimming the base of this pot almost bone dry

I’m getting better success rate these days with each variation and improvement of these techniques. It’s a little frustrating to loose so many pots, but they slake down quickly and can be stiffened in plaster tubs out side, then re-thrown within a week.

It would be better to leave the body to ‘age’ in a cool dark place for a month or two, but with so many variations of sericite porcelain bodies in constant testing and development. I’d loose track. As it is I really have to concentrate and keep very good records, marking every bag with a permanent marker, identifying every bucket of turnings in the same way and carrying this over to the slaked recycled material in the buckets and in the plaster tubs. It’s quite a paper trail of provenance, keeping track of it all. I also keep a daily diary in the workshop of what I’m throwing and what I’m throwing it out of. Every pot gets inscribed with the batch of body and later identified with oxide as to which glaze I used. I also keep log books for the glaze and the body ball mills, so that I know what I made, the date it was done, and what it was made from. I always seem to have a dozen different batches on the go at any one time and they all need their own bucket and bag storage space. It’s organised chaos.

I’m nothing if not thorough. I have to be. With over 3,000 glaze tests and hundreds of clay body tests. I need to keep track. I really want to make simple, elegant, beautiful things. But things with a particular character that I admire. Just a little bit ‘damaged’ or altered by the process of their making. Perhaps I should say ‘enhanced’ by its process and journey, plus the unique quality of its material. I like my pots to have a story embedded in their form and surface. I can pick them up years later and ‘read’ that story. I like that.

I’ve just made a few more white tenmoku bowls. They are slightly bigger, fuller and rounder, more generous in feeling, less austere. I haven’t finished turning them yet. They still need more work over the next few days, but I have high hopes for them.

Unfortunately high hopes are not enough. It’s long term, steady, pains taking, thorough and often boring, consistent research that makes progress for me.

That’s really rewarding!

27 Kilns in 27 Days – vol 5.

The tea plantation potter.

We visit a potter in the Longquan region who specialises in the dark bodied celadon wares of antiquity, but not guan ware. However, he has been and still is a great fossicker and has the most amazing collection of authentic old Chinese shards that I have ever been lucky enough to sit and handle. It’s like being invited into the back room of a museum by the curator and allowed to see all the little gems that never make their way out in the glass cases.

A lot of these shards look to me to have been excavated from out of river beds or streams. Many of them appear to have been water ground on the edges. I see this exact quality on my pots after I have tumbled them in the ball mill to ‘age’ them.

It’s the white impregnated crackle of the crazing lines that give it away, and the soft matted surface, also the rounded edges on some pieces. It all fits. I saw pieces like this in the museum collection in Malaysia. They have a whole section of pots of Chinese origin that were recovered from ship wrecks off their coast, by archaeologists, in recent decades.

Pots that were packed inside other larger pots were left with their glazes largely intact, but pots that were spread out from the cargo hold and scattered around on the sea bed in the sand, were completely relieved of most of their glaze surface except in the crevices around the foot ring. I saw one pot that was only half exposed because it was retained inside something else. The exposed surface was cleared of its glaze, just as if it had been sand blasted.

This private Longquan collection also had a lot of shards that had split, shattered, and for want of a better word ‘delaminated’. That is, the pot had been split down the centre of the clay body, more or less evenly between both layers of glaze, when the thick coating of glaze on each side of the pot exerted massive pressure on the glassy body from each side. The glassy nature of this dense, vitreous, proto-porcelanous clay body was forced to seperate, or shatter, down the centre into two parts. I suffer this exact problem in my work occasionally.

It’s somehow reassuring that the Song Potters of ancient China experienced the same issues that I am grappling with. They managed to solve all these problems in the thousand years that they have been potting. I have just 50 years. I need to work harder.

The problem shows itself, if or when, I apply the rock glaze celadon glaze too thickly over the body. The problem isn’t apparent immediately, but only shows itself after firing, as the difference in the coefficients of expansion and contraction is expressed differently in body and glaze on cooling. At around 230 oC the exotic ‘cristobalite’ form of silica, that is often created in the clay body at high temperatures, undergoes a beta-alpha phase change and shrinks 2 or 3%. This sudden shrinkage at such a low temperature exerts such tremendous pressure on the body-glaze interface, that something has to give and sometimes the pot shatters into pieces. However, in this specific case, the glaze shrinks more than the body and the glaze tears the brittle body asunder.

There is a dramatic variation of this problem that occurs when the glaze is applied to the raw clay pot when it is bone dry. If the pot is glazed on both side simultaneously, the water based glaze entering the pores of the clay is drawn in by capillary attraction. This forces air in towards the centre of the body of the pot. There is such a build up of pressure that the pot can explode with a quite loud ‘POP’! A piece sometimes flies off, or at other times a coin shaped disc flings open, left hanging, with a slight hinge on one side, allowing the air pressure to escape. It really shocked me the first time this happened to me, when I was a student at art school, as I was still holding the pot in my hand, having just lifted it out of the glaze bucket. The solution is to glaze only one side of the pot, let it dry and then glaze the other side. Thus allowing the air to escape harmlessly each time, out from the other side of the surface.

Guan ware on the other hand, has more or less the same glaze, applied even thicker on occasions, but the shattering problem is avoided in this traditional ware because the body is porous and friable. The porosity of the clay allows the cracks that form due to the glaze cooling stresses to dissipate into the porous cavities and terminate quickly without passing straight through the body, as they do in vitrified and glassy porcelaneous clays.

A shard of guan-like crackle glaze.

There is such a lot of chemistry and physics to be learnt in making ceramics! I was at the Royal Society meeting last month and heard the speaker tell the audience that in science, there is only ‘physics’ and everything else is ‘stamp collecting’ or applied physics. A mathematician claimed that there is only ‘Pure’ mathematics and physics and chemistry is just applied maths. It seemed to me that there was some agreement that biology was stamp collecting — except from the biologists. Perhaps psychologists could claim that without ‘mind’, there can be no maths?

Anyway, what would I know, I’m just a stamp collector! A stamp collector who applies chemistry, maths and physics in a creative way to ceramics. I also apply stamps to my pots to identify them as mine.

The potter who had collected all the shards, had a big new concrete double story workshop. He was the leading student of the best student of a very important local potter in this region. Sort of 3rd generation celadon maker. I got the impression that the property that he workshop was built on was his parents land. Whoever’s land it was, it has a beautiful tea plantation covering it. The new workshop has a full wall of glass looking out onto the rows of tea.

A view to die for. So beautiful! I wouldn’t mind a view like that when I’m throwing pots.

27 Kilns in 27 Days – vol 4

We get to spend a day in the Longquan Celadon Museum. I am travelling with my friends Len Smith and Robert Linigan. I am very interested in these old Celadon pots, particularly from my point of view of the inspiration that I can gain from the best pieces and equally importantly from what i can learn from the shards and broken sections. There is so much to glean from being able to see inside the clay body and looking at the interface between the body/glaze layers.

I love these rich and sensuous fatty celadons, guans and ‘ru’-like glazes. These are some of my favourite pots. It’s not too surprising that I like to try my hand a making glazes with this kind of influence. I wish that I could make something as good as this. It’s a quest.

In particular, I am keen to make my clay bodies and glazes as authentically as possible, by digging up all my own minerals, rocks and stones, then mixing them with ashes from my fireplace, where I burn the wood from my own forrest. It’s a complete commitment to my philosophy of self-reliance, not just in ceramics, but in my life. This coupled with a keen interest in the soft delicate beauty of ceramics the way I envision it. Not just the look, but also the feel of the surface. Equally important to me is the tactile impression -‘feel’ and balance of the pot in my hands, as well as how it will function when I eat or drink out of it.

My favourite coffee bowl at the moment, for my morning bowl of coffee, is a small white tenmoku bowl that is very translucent and very white, made from one of the Chinese sericite bodies that I have experimented with. It gives me a lot of pleasure just seeing it and handling it, even before I drink the coffee from it. It is beautifully balanced, only slightly weighted to the lower half for stability. It looks and feels gorgeous. I’m particularly fond of the slightly out-turned rim that is an essential quality of the tenmoku form. I’ve been using it for a year now and I’m still not bored with it.

Some of the unique qualities that I find I really engage with, are all its ‘faults’ – if that is what they are. I prefer to think of them as being part of its unique character. You can’t buy this bowl from Aldi on special for $2. Their white bowls may look superficially similar, but this pot has a story embedded in it that is only very slowly revealed over time as you get to know it.

For instance, because I’m not a very good potter, I don’t go to all the trouble of trying to make things perfect. Simply because I realised long ago that perfection only exists in the mind of the beholder, therefore can never be achieved, so why bother. Better to make things with character. This bowl for instance has a slightly mottled surface to the glaze, it has a very gentle undulation where the very thin clay body saturated during dipping and the glaze didn’t adhere perfectly. I have come to love this slight quirk of its appearance more than the very smooth glazed surfaces that I can sometimes make. This is a special part of this pots own history of its making.

Another point of interest for me is the hint of the remainder of the clay slurry on my hands left embedded in the surface of the clay after I finished throwing the pot on the wheel. I left it there as a reminder of the touch of my fingers. It is almost imperceptible, but it remains. I wasn’t aware of it presence initially, but it slowly became apparent to me as I got to use it, handle it and wash it up often. Not all my pots have this effect left in them, sometimes I wipe the inner surface clean with a fine textured sponge. At other times, I turn the inside of the pot with a trimming tool when I turn the foot. It all depends on how I am feeling about the pot as I make it. I never quite know how I am going to feel about what I make on the day. So its a surprise to me to be reunited with my own pots, post firing, and to re-discover their special qualities.

I can just see this swipe of my fingers in the image above. You won’t find that in a pressure cast or jigger-jollied bowl from IKEA.

This bowl also has a single iron spot in the glaze, just below the rim. It’s a bit like a beauty spot. I didn’t put it there, but I’m OK with it. This is a real object of beauty and interest. It isn’t perfect. It’s just gorgeous. It also shows my two stamp impressions. One is my initials, the other is the workshop stamp.

Finally there is the total lack of an obvious foot ring until you turn the bowl over and look underneath. I hid the foot recess inside the bowl form to minimise the weight, so as to keep this delicate bowl as light as is possible, but still have an elevated form that lifts it up off the table in a continuous elegant curved line. This is not true tenmoku form, but I think the it is better on this pot.

In the Longquan Museum we saw a lot of shards with loads chipped edges, shattered rims and broken bases. I loved this part of the display. It was all real. Many of the perfect examples had long ago been taken away to other larger collections, as this is only a smaller regional Museum. What was left in this Museum were all the other pots. I learnt a lot form looking inside the shards to see the very same qualities, problems and faults that I get in my work, using very similar materials and and almost identical techniques.

What I found particularly reassuring was that I am not alone. Someone else, 800 years ago also went through all these technical trials and difficulties to arrive in a similar place. Ultimately, there is the reward of the occasional lovely piece that survives.

This bowl is lovely, but what others probably don’t see, but I did, was what, at first glance, appears to the an incised line inside the bowl. That is easy to see, but it is in fact not an incised line, but a remnant of its making that appeared in the kiln during firing and wasn’t there when it was packed in the setting. It was formed in the fire. That wavy line is the raw glaze surface drying out and cracking slightly. The crack then doesn’t completely heal over when the glaze surface melts, but remains as a line in the glass. Perfectly fused, but hinting at its life before it became ceramic. I get it often in my glazed surfaces. It used to annoy the hell out of me, as there was no way that I could see to prevent it happening, if you fire long and low to make that particular satiny surface, it’s just what sometimes happens. If you fire hot, it disappears in the fluid melt at top temperature. This ‘scar’ is a relic of its process and making. I now look on these healed over cracks as an authentic product of the unique process that I indulge in.

Nothing is perfect. Nothing lasts. Nothing is ever finished, and that includes learning.

The life of a bearing

I used a wooden framed, foot operated, treadle, potter wheel. It’s a very old ‘Leach style’ potters kick wheel. Designed by Bernard Leach, way back, early in the last century. That’s almost a hundred years ago, coming up sometime soon. This actual wheel was handmade in Australia under licence sometime in the 1970s. That makes it almost 50 years old.

When I started to learn about hand made pottery in 1969 I bought a 2nd hand ‘Leach’ kick wheel to get me started. I loved it so much, that I have used them ever since. I have tried other pottery wheels, but keep on coming back to this energy efficient, human powered potters wheel. Tragically that first wheel was lost in one of the two fires that have devastated our pottery workshops over the 50 years of my career as a potter.

The other day I was throwing a large pot of 3 kgs of clay. Not so big compared to what other younger potters can throw on an electric powered potters wheel. But about as big as I like to go on this old wooden treadle wheel. Well, I was pushing hard to get the mass of clay onto the centre, when ‘CRACK’ ! That was the end of my throwing session. I had busted the leather bearing that connects the foot treadle bar to the steel crank shaft. It was reminiscent of peddling your bike when the chain suddenly comes off the derailleur gears. Everything sins free and there is no response to the effort of peddling.

Now it just so happens that only last weekend I was at a ‘Lost Trades’ weekend market and exhibition and my good friend Warren, the guy who can do anything. Warren decided to buy a hand made leather belt. But his plastic card wouldn’t work on the ancient, lost trade, candle powered, banking machine that was available on the site, so I lent him some money to pay in old fashioned cash. The Lost Trades traders still have the ability to take cash! That is a skill that isn’t lost!

I asked the leather worker if I could have the excess leather from the very long blank belt was was being custom fitted to my friend. I got 300 mm of leather belt material. The leather worker, who I knew, knows that I am a potter, and I have bought my belts from him in the past. He asked me what I wanted the leather for. I told him about my very old potters wheel and its antiquated leather bearing. How amazing that the very same piece of leather bearing would snap just a week later. I am so lucky!

.As good as new – well almost

So I had to stop work and do a running repair. I was prepared. In less than an hour I was up and running again. I bought this potters wheel 2nd hand, after the last fire in 1983. The old leather strap had lasted 36 years! Not too bad for a thin leather strap.

I’m wondering how long this new one will last? I only used half of the piece of leather for the repair, so I still have another piece in reserve for 2055.

I’ll be over a hundred years old by then, so it probably won’t be my problem.

Kiln Disaster

Well, this is a bit of a sad tale. I have unpacked my latest kiln firing, only to find that 2 of my very expensive Japanese Silicon carbide kiln shelves had snapped during the firing and collapsed onto the work below.

Not a pretty sight.

The second and thord kiln shelves from the top have both broken.

Even though we lost 3 shelves worth of pots crushed or stuck together. There were still some very nice pieces to keep our spirits up.

The bottom shelf was OK.

Despite the disaster, there were still a lot of lovely pots that came out.

There is some nice subtle grey carbon inclusion and delicate ash deposit on the unglazed surface of the clay body.

The collapse seems to have diverted the flame path a little, causing some parts of the setting to get hotter than usual. This resulted in some over-firing and running of the glazes.

When the pale celadon glaze runs, it forms a very nice emerald green pool in the bottom of the pots. I really like the whiteness of the sericite body, contrasting with the emerald green pool and the pale hazey grey of the carbon inclusion on the rim.

I get out my quality control hammer and start to process some of the sub-prime pieces. They go into the ball mill, where they are polished for a few hours. When they come out, they are used as hand made celadon porcelain gravel ‘jewels’ for the driveway and paths.

This is one of the over-fired bowls below. The glaze has started to run, but it is still really beautiful. The runs have a build up of fine white ash glaze crystals. The pot has remained startlingly white, even with the wood ash attack. The glaze stopped just short of sticking to to the kiln shelf. What I find amazing, is that the sericite is so translucent at this higher temperature, that I can not only see light through it, but I can see the runs of glaze on the out side of the pot from the inside!

This doesn’t happen very often. It also has a beautiful, intense, emerald-green pool of celadon inside the base.

Its a really unique piece. You can even see the pink colour of my little finger holding the base of the pot on the other side, underneath. That is translucency! I’ll probably show it at Kerrie Lowe Gallery in November/December, in her Xmas exhibition.

I have kept one really translucent, but damaged bowl on the window sill in front of my wheel for inspiration. It’s ruined, the rim was destroyed when the kiln shelf on top fell on it and it is warped out of shape from the pyro-plastic deformation at the high temperature of 1300oC. Luckily, I was able to prize it off the bottom of the kiln shelf in one piece. It is so white and translucent, it’s an inspiration to me to see what is possible with this special ground up rock style of clay body called sericite.

I try not to think of the hours I spent working on it, turning and trimming it over several days, in various sessions, until I got it down to an even 2mm thick to get this result.