Saturday 28 April 2012

A test firing to cone 7

Here are a few results from yesterday's test firing. I say "test firing", because some of the glaze and slip combinations were experimental. The first photo is of the cappucino cup I showed unglazed in a previous post..it had the white slip applied after bisquing the black slip. 5% ferro frit was added to the transparent ash glaze as a flux, and on this piece it's cured the bubbling and pinholing problems..but i'm wondering if this is because I brushed it on very thinly. I also want test this glaze at cone 9/10, but I rather like the buttery, matt surface achieved at this lower temperature.


( It wasn't easy to photograph these slipped pieces, so the colours probably aren't 100% accurate. )

The next three pieces were combinations of black and white slips with the Leach 4321 glaze, plus about 3.5% tin. I was expecting that the glaze would come out semi-opaque at this temperature, as there's quite alot of tin oxide in there, but apart from some micro-bubbles, it's still pretty much transparent.





Where the black slip is partly covered over, it has a slight magenta tinge to it. Quite a pleasing effect, but I would like it to come through stronger and darker.

Thursday 26 April 2012

A mystery stone

It was raining alot today, and as I walked through the garden, a wet, shiny stone caught my eye. It looked very unusual to me, because I've never seen a stone before which looks as if it's been cut perfectly in half. The cut side is absolutely flat and smooth, like ground glass..there are no markings from sawing or sanding. There are a few tiny chips around the edge but no damage at all on the surface, not even a scratch. That in itself seems a bit weird, when it must have been knocking around the garden for years.




The outside has an organic, wrinkled texture, almost like a seed, whilst the inside is like a translucent marble, or flint. The muted colours remind me a little of an anagama-fired pot. It's too cloudy to see inside it, but there are vague crystalline structures going on in there.

I'm sure geologists would provide a perfectly rational explanation (perhaps it was a geologist who discarded it), but I prefer to think that aliens cut it in half with a laser, and took the other half home as a sample. ;)

Update: someone on facebook has told me it's probably flint..is this how flint stones break then, with these perfectly flat, clean surfaces? Maybe it's not so mysterious after all..

Another day, another clay

This is my last post about mixing clay for a while, I promise! This morning I've been wedging up the new clay with around 60% Earthstone Original and 40% Original Raku. The photo shows how much more plastic it is:


The clay on the right has more iron oxide as I tried adding some red stoneware clay to it to make it more plastic, but to no avail. I'm not sure how I can improve this body without adding more and more smooth clay. I can throw with it okay, but it's easy to trap air bubbles when kneading.



I made a couple of bottle vases with it yesterday, but I am more pleased with the shape of the one at the front, which was thrown a few days ago.

Tuesday 24 April 2012

At last, a little sunshine!

Finally, a beautiful day today..a few clouds here and there, but lots of gorgeous spring sunshine. I wish I had some pictures of new work to show here, but the clay situation is still distracting me and preventing me getting on with glaze firing. I really thought I'd solved the recent problems by mixing smooth stoneware clay in with my coarser, groggy stuff. Well, it's perfectly fine when wet and soft, but as soon as it starts to firm up it becomes unworkable again, even with a large proportion of smooth vs. rough clay. It quickly becomes completely non-plastic and just falls apart when wedging. Frustrating to say the least, and I've never had such difficulties with clay before (except after it's been frozen).. I think maybe I'm paying the price for buying a slightly cheaper clay, which has too much sand in it, and not enough plastic ball clay etc. Anyone else out there had similar problems I wonder?

So today I fetched some more expensive clay, Earthstone Original (ES5), which I know is a reliable body as I've mixed it before with the Potclays original raku very successfully. It makes a lovely, groggy mix, very easy to throw with..I have Yo Thom to thank for this recipe, found in the book "Techniques Using Slips" by John Mathieson.

I'm also happy to have found a possible source for the French stoneware clay which I've really enjoyed throwing with in the past. It comes from St Amand en Puisaye and is a very dark, grey colour when wet. When bisque fired, the organic impurities burn out and it turns a very nice pinky buff colour. It has some iron in it, but not too much, and takes salt very well..also gives nice orange and red colours with shino glazes.

Just to add a little colour :)





Wednesday 18 April 2012

A few softer forms

The clay is much easier to throw with now, so I've been playing around a bit the last couple of days, throwing some new, softer forms. It usually takes me a while to decide whether I like the pieces I've made.

the bottom of this one will need trimming a little

it wasn't meant to be tear-drop shaped, but I quite like it for now


The piece in the last photo took me longer than usual to finish..I had great trouble getting the top section into the right shape, and deciding whether it should have a neck or not. I'm still not sure if I like it, but I was fiddling around with it for several minutes, which is usually not a good sign.

Longing for some sunny days here..the weather has been really awful for the last week and a half.

Monday 16 April 2012

Throwing larger pieces

I've been struggling with my clay the last few days, trying to develop a decent body for throwing larger pieces. I really don't like throwing (or should I say "really can't throw") with very smooth clay, so I'd bought a hundred kilos each of lightly grogged stoneware clay and raku clay (very groggy), and tried mixing them together in various proportions. It's not a bad combination but lacking much plasticity, and as soon as it dries out a little the clay begins splitting and falling apart when wedging. Soooo, I had to go back down to Valentine's today and buy a load of smooth stoneware clay to counteract the over-grogginess. The traffic in Hanley on Monday afternoon is something to behold, especially with the added joy of roadworks in the centre..I was pretty glad to escape the snarl up and head home.

The price of clay seems to have shot up over the last few years, along with everything else. I considered trying some White St Thomas clay, but they are now asking a hefty £16.45 for a 12.5kg bag! It's alot cheaper if you buy 100kgs, but it still works out at around £10.00 a bag.

Anyway, I wedged up a new batch as soon as I got back and tried throwing a jar with a rolled rim. Only my second attempt at this form, so I was fairly pleased with the result. Ideally, with some more practise, I'd like to throw them a little taller, with a thicker, more "wabi-sabi" rim.




The Japanese are masters at making vases of this shape, and I am in awe of the work of potters such as Otani Shiro , who works in the Shigaraki tradition.

Wednesday 11 April 2012

A test form

I've been playing around with new shapes on the wheel, and tried to throw a sort of pine-cone form off the hump.


I guess one might call it "egg-shaped " too, but then that word "egg" covers multitude of possible forms. Originally, this was going to be a little mustard pot, but then I cut out the lid wonkily so I stuck it back together. I'm just keeping it as a reminder of the form, and since then I've made a few lidded pieces like this, one of which I smashed yesterday.

This morning I turned it upside down, and was struck by how much it looked like a human head.



Not an earth-shattering discovery, but maybe I could make a similar one as a sculpture. Just need to figure out a way to make it stand upright on the pointy end..maybe a plinth with a hollow in the middle could work..or a steel support with a ring for it to sit in..

Tuesday 10 April 2012

April showers and a small revelation

The weather is matching my mood today..sunny then cloudy, then sunny again in quick succession. The bisque firing I did yesterday was very successful with no cracks or explosions. But then, as I was putting the fired pieces on the shelf, I pulled my hand back, and the back of my glove (pots were still very hot) caught the knob on top of a  lidded jar and off it went, falling to it's death on the concrete floor below. *Sad face*.

Next, I pulled out this little coffee cup, and was amazed to find that the white slip had stayed completely intact. I'd already fired this once before with a layer of black slip applied at leatherhard, and I thought I'd try doing some hakeme brushwork over the top. The slip was applied fairly thickly onto the bisqued clay, and normally I'd expect at least some of it to peel off. There is a bit of cracking in the crevices of the handle, but that will actually look great under a clear glaze. Not sure if I could then apply glaze over the top of the slip without re-bisquing, that will need another experiment. It would be useful if I could, as one of the problems with hakeme at the leatherhard stage is contamination of the white slip with iron oxide etc. from the dark layer below. Ofcourse, the mingling of the slip layers may also add something to the decorative effect, so it will be interesting to see what the differences are after glaze firing.



The white slip is 50/50 hvar ball clay and china clay. It might work really well..if the glaze is applied over the still-damp slip layer, it may result in a thinner application of clear glaze, which is something I want to achieve. We shall see!

Apart from stabbing myself in the finger with a needle tool, the day is now back on track. Time for some throwing followed by lots of decorating and glazing.

Friday 6 April 2012

More work in progress

Brrrr, it's gone chilly again here, the clay was so cold on my hands this morning when rolling out coils. I've just finished the piece below on the right and I'm quite pleased with the way it's turned out, partly because it's the biggest thing I've made for a while.


Tallest one is about 12 inches

I've decided to keep these as closed forms, it will certainly make them alot easier to decorate with slip. Difficult to see on this photo, but they are roughly triangular in cross-section. I also decorated the lidded jar below with black and white slips..ideally, I could do with a larger hakeme brush which will create longer, more sweeping strokes.



Hakeme is certainly an art form, which like everything else in ceramics, requires dedicated practice. The slip needs to be at the perfect consistency, so you can lay down the top coat in as few strokes as possible..it also takes experience to be able to guess how the surface is going to look after glaze firing, once the dark iron slip burns through. I painted on the slip with the lid in place, so it will be interesting to see how easily it comes off again without ruining the decoration.

Tuesday 3 April 2012

More experimentation with closed forms

Five lidded vessels and two carved sake cups

Recently, I've started making a series of these lidded jars, and I must say, I'm really enjoying the experience. I'm finding that this kind of closed form allows alot of scope for experimentation with shape and building techniques. Some are thrown whole and others are thrown and coiled. Adding a coiled component to the form gives them a slight asymmetry and perhaps more character and individuality. It also allows me to slow things down and think carefully about the outline as it develops, although there is always an element of uncertainty which I like too.

I'm not sure yet how I'll try to finish these pieces. I'd like to do some finger-wiping through slip, but the timing of that is tricky since the lid has to be cut through by hand. Adding lots of slip will soften the piece again and it will be difficult to cut the lid out without disturbing the slip layer..so I may have to add the slip after making the lid, which then creates other issues. I might also do a combination of underglaze decoration with poured ash glaze..I've been inspired recently by the freedom of expression in Toshiko Takaezu's work. I'd also like to leave a few plain, or perhaps just give them a layer of terra sigillata, then fire them in a wood kiln. Some gentle flashing on the surface of these  pots would probably work well.

I also enjoyed reading Ron Philbeck's blog today..in his last post he says how furiously hard he worked yesterday and yet only managed to partially complete five pots. I must say, I laughed when I read it, because I have so many days like that myself, when I'm left asking myself where all the time went and what the hell have I actually achieved in 24 hours. For me, the truth is that I spend more time than I should, thinking about and evaluating what I've done, what I'm going to do, the processes involved and where my work is heading etc., and maybe not enough time grafting at the wheel head. Work involving hand-building really slows you down too, and it's difficult to get a production flow going when pieces are at different stages of dryness. And ofcourse the weather affects how long the clay can be left before it requires attention again. The other problem for potters (like most artists!) is that, ideally, demand needs to match production... I remember reading about Suzuki Goro, who, after years of practice, was able to throw about 1250 yunomi in ten hours! These days in the UK, there just isn't the demand for hand-made, functional pottery to allow you to market pots on that scale. Having said that, maybe the secret is to make 1200 and only keep the best ten..but then I wouldn't fancy recycling all that clay by hand..

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A small selection of my work is available on Folksy

Monday 2 April 2012

The Perillos Stone


An ancient stone menhir with what appears to be a human face, naturally etched into the rock.

More information here: http://www.perillos.com/cromlech.html

From the page:

What we do find, in the valley below Perillos, is an enigmatic stone, which opens up new lines of research and leaves us with some questions. This stone is limestone, and thus local to Perillos. It appears to have nothing out of the ordinary, nothing to distinguish it from the so many other scattered stones that are everywhere. But a closer inspection will show that this rock is different from the rest, as it seems that the outline of the stone is that of a human face, with an open mouth. It is clear that the stone is not sculpted, but the face is remarkably there, sculpted by nature itself… In pagan days, these stones were often set aside as sacred, as they were deemed to have been sculpted by the gods themselves. Such artwork is now described as “subliminal”, though often, such as in certain Palaeolithic caves, the design was stressed e.g. by the addition of a telling line. Mankind thus “accentuated” God’s handiwork.

Sunday 1 April 2012

Sunny days are here again

Well, we've had a beautiful week of weather here, and it's been lovely working in the studio with the sun streaming in through the doors and windows. Clay work which was taking three or four days to become leatherhard is now drying too quickly. Late last night I made a handle for a mug (we're not talking mass production here) and left it on the bench overnight to firm up a little..by the time I got to it in the morning it was rock hard and dry as a bone, so I had to chuck it away and start again. Usually that kind of thing only happens at the height of summer.

The only slight downer is that I've been feeling rather ill this week with some kind of weird bug..it's been like having a bad cold coming on but it never quite arrives or goes away. I'm grateful not to be laid out with the flu, but I've been pretty sluggish and lacking in energy. Hopefully it will be gone next week as my plan is to spend some time designing and building an experimental, mini wood-fired kiln. It's going to be a proper Heath Robinson concoction, mainly using kiln fibre and fencing mesh to make the kiln chamber, and Durox blocks for the platform. I've no idea what kind of temperatures I'll be able to reach with it..I'm guessing high earthenware (1150 degrees C) and I'll be delighted if I can get it up to cone 4 or 5.