At last - some pots!

I unpacked the kiln last week and set all the pots out in my workshop. Many of them are pretty scarred and crusty with wadding and run glazes so there's plenty of grinding to do. But I have been so delighted with the results and so stressed that they might disintegrate that I've been leaving them alone till all the crazing has subsided. A few pieces (from Leicestershire materials) have auto destructed (dunted) but the rest seem fine. So.... a little tentative grinding today.

These two were from the front of the kiln - up by the firebox. The ash deposits have a yellow/gold crystallisation, which could be from the Hornbeam I used along with the Beech. I'll see next time when I'll fire with the rest of the Hornbeam.

Fired and opened!

I started the firing last Thursday at 7am and finished a bit earlier than usual, at around 2.30pm on Friday. Andy came over to help, which was great. I did a slightly looser pack at the front than usual with only one level of shelves. There was also an extra foot on the chimney and I refitted the grate area at the front. The firing itself went very well. Nice and smooth up to around 1100C then still a bit of a nudge to get it up to cone 9 down throughout, which we managed by around 8pm. A night of slow soaking, then gradual temperature rise till cone 12s down. This is usually another nudge but was pleasantly relaxed this time. Less reduction than the usual and then a few days of nail biting.

Today was the big day + with my heart in my mouth I opened it up. The photo is the view from the front, which is usually the best spot. The lesser reduction had made a difference here, which isn'r quite as good BUT the rest of the firing seems (so far) mercifully very good - especially considering it was really a very large test firing!
More images later.....

Many many days later......

Well, it's been a long time since I posted anything. After the last test firing I went on a few trips to collect clay samples and started preparing for a large wood firing. This pile of hornbeam is now nicely cut, split and stacked ready to go.

Then, many many days of preparing raw materials: clays and rocks. It is all just so incredibly time consuming. I've never really previously considered the ease in just opening a bag of commercially prepared clay, but from now on.......well, I'll never look at a bag of clay in the same way!
The firing has been delayed more and more as I grapple with practically every ceramic fault known to man, but at last I am glazing and doing a quick last minute biscuit firing. Packing next week and then firing. Andy has generously agreed to hep me again and I am now hoping for a 2 week continuation of the mild weather.
More posted soon - honest!

Good firing!

Yes yes yes. It was a beautiful sunny day, which bode well for the opening and....
it was good.

The reduction wasn't as heavy as usual, I got some of the dreaded 'melon skin' but temperature was perfect. This is the front of the stack. Left hand side all a bit weird as it seemed to miss out on the path of the flame.

...and here's a little beauty from the middle of the top shelf. Overall it was pretty good with a selection of real stunners. The modified kiln was rather problematic to fire + caused a few cool/weird areas in the chamber, so I won't be doing that again. Full kin next time.

New vid - past firing

http://youtu.be/e5eWb0zDLRE

Here is anew video I've put up, while waiting for this kiln to cool. This was shot in 2010.

FIRED!

The rain held off long enough for me to actually light the fire.....

It was an experimental firing - all the pieces in it were/are tests and, so that I didn't have to fill the entire kiln, I reconstructed the inside to block off the second chamber.

I wanted to see what a shorter firing was like as well, especially considering all the work in there was glazed in some way.
My concern with this modification to the kiln was that it would collapse, or act like another 3 feet of chimney greatly increasing the pull of the chimney. In the event neither concerns were founded - on the contrary, the draw on the firebox was reduced and I had two sticking points where I had to work very hard to get a temperature rise.

I lit the fire at 7.30 am, started reduction at 2.30 pm and continued firing till 3am when cone 10 was down and cone 11 just touched. 19.5 hours of hard stoking on my own and I am now absolutely knackered. But the day itself was fine. By 1am I had my second (or third) wind. Totally wired on adrenaline and fizzy pop. But it was fine - I could have gone on for a few hours more if needed.

Toasted the firing with a pint of Fullers ESB (best beer in the world) and sealed it all up. It's still at 900C at 1pm this afternoon.

Many many hours later......

.....after rock crushing, clay crushing, blunging, stiffening, making and glazing I am finally almost ready for a wood firing!!!!

Very exciting. After many gas test firings it is now time to see how all these materials behave in a wood firing. The kiln is all cleaned out from ash, wadding and red admiral butterflies(!), and I've made the most of this (sadly rare) sunny day to get all the wood ready.

Beech this time - perhaps the last of it (depends how much I use). Next time will be hornbeam, which I haven't fired with before.
The kiln is two chamber but as it is a sort of test firing I am going to brick off a lot of the second chamber so I am only really using the firebox area. Hopefully this will work well - just have to see. I will try and post a video of the firing.....

Ou est ici?

Hmmmm. Je ne suis pas sure que ma Francais est any bon at all.

Peut etre my O'level Franglais has given it away.... White sand, cloudy, geologically intricate igneous coastline? Could well be Cornwall but if I mention that after this walk I washed down a plate of gloriously fresh huitres with un bouteille de delicious Muscadet you will know that it is that geologically linked area in France, North Brittany.

It was a holiday of course, but a man in search of rocks is never really on holiday and when I saw the pink granite that the area is famous for, sculpted into these amazing Henry Moore'ish shapes I couldn't resist.

I must've been the only person on the ferry to Dover who had his car weighed down with rock rather than cases of tasteless beer and Australian wine.
I wasn't intending to collect anything here but the beaches were amazing for the variety of rock pebbles that were piled up. Granite (pink and white), schist, mica schist, slate, dolorite, great beautiful slabs of quartz and loads of others that I can't identify. Certainly the richest variety of materials in one small area that I have found so far. It's the first place that I have managed to find everything I would need to make a series of glazes in one square metre.
Oh yes the holiday was fine....good swimming, great food and wine, Belgian beer, historic towns, BUT WOW...You should see the rocks!!!

On my knees.....

....begging for some kind of flash of inspiration.

....aaaah, but what a beautiful place to do it. Back in Devon this time, scrabbling round in pathways for little pieces of potters gold. Yes, pure feldspar. Lovely stuff.
This time I managed to focus my site collections a bit better and I visited a couple of new places, including a secondary clay pit. Stayed in a pub and the sun shone enough for me to sit in the beer garden in the evenings and I really couldn't have been happier. Wednesday night was the night of the lunar eclipse and I climbed up to Haytor to hang out with the druids for a moon party. Unfortunately when I got there I could see that the big gathering was at Hound Tor, a couple of miles away and at least a mile further than my interest in druids.
I did visit the David Nash exhibition near Exeter, which was fantastic!

It's a small selection of work that he had at the Yorkshire Sculpture Park recently + at a place called Haldon Forest Park. If I knew how to put a link in on the blog I would.....

The real reason for the syringes.....

I haven't posted anything for a couple of weeks and the reason is long long hours of rock crushing, grinding and volumetric blending - none of which are immediate enough to be photogenic or exciting enough to be written about. Still, due to popular demand (one comment) here is one of my Edinburgh biaxials.

Basically it is a way of testing glazes that gives far more insight than just mixing up an individual glaze. The basic glaze has two variables, one along each axiz, so that a sort of map is made up. The first 4 vertical rows on this tile are a 20 glaze biaxial based on a basalt rock. The two variables are calcium, which is increased from left to right, and silica, which is increased from top to bottom.
4 corner glazes are mixed up to a specific volume and the rest of the glazes are made up by volumetrically blending these glazes using syringes.
It's a long process and as you can see from this tile, rarely gives a final glaze - more an insight into how the materials are behaving. Most of these glazes are rather revolting brown sludges but there is a bit of promise around glaze 14, so this will be the starting point of the next.....Onwards and upwards.....

It's over......

......no no, settle back....it really is Over. Near Cambridge. The site of one of the largest open quarries in the UK, and also one of the 2 largest sites of mesolithic, neolithic, bronze age and iron age flint tools. In fact, while I was seiving through a large pile of sand I found a mesolithic flint blade that was napped between 6.5 and 10 thousand years ago.
The image shows students working on the site, excavating fire pits etc. In the morning they napped flints and used them to skin rabbits, then had a go at pit firing pots that they had made. It was carnage! It was reassuring to be an onlooker and realise that I do actually know something after all.
I was there to get my hands on some of the Oxford clay, which sits under the gravels, flints and the sand there. I checked out some of the river clays that had been deposited later but here they were far too high in organic matter to be any use.
Back home the ball mill is running at full pelt. I've broken my steel mortar and pestle(!) so there's welding to be done and then it's out with the syringes for biaxials from Scotland......

I've got a tan.......guess where I am.

It's a beach and this is bank holiday Monday, so definitely not anywhere in East Anglia.
Clue: it was a scene of violent carboniferous upheaval, where the local sedimentary rocks were ripped and split apart by a giant volcano with numerous plugs, dykes, sills and laccoliths.
Clue 2: James Hutton developed his theory of geology here and there is a section of rock named after him.
Yes indeed....it can only be Edinburgh - but look at the sky! What a total pleasure it was fossicking in this area.

This rounded dome is a microgranite batholith. I'm ashamed to say that after 2 days of climbing and walking I only reached halfway up the side of this.
Now home, with another carload of samples and preparing for another day with the Cambridge archeologists......

Lateral thinking

The best thing about the slightly vague open idea of this project is the chance to take an idea in a previously unconsidered direction.

My visit to the quarry in the north of Cambridgeshire with the Archeologists was particularly interesting. I managed to get samples of various clays that are rarely exposed, that have been laid down in quite specific time frames - from the Jurassic until the last ice age that extended across East Anglia. The site also contains samples of pottery from Neolithic, Bronze Age, Iron Age and Roman times, which this image illustrates.
Not only am I investigating these clays for my own use but am helping the Archeologists ascertain which clay deposits were used by potters in these different eras. My next task is to fire samples of these pot shards to different temperatures, along with test bars of the clays to compare colour, texture and porosity as the clays progressively fuse.
It is surprising just how lacking in strength (low-fired) most of these samples are. It is only the Roman that shows signs of maturity and along with the late Iron Age sample, any strength at all.

The Kingdom of Rain

A quick post from the breathtakingly beautiful Lake District. Had a couple of glorious days and now am getting a long demonstration of why there is so much moss around on everything.

Last time I was up here I had a thick mane (?) of dark hair and my rucksack was full of beer and provisions rather than rock samples......

Clays of Cambridgeshire

So.....I've sorted through the various deposits I sampled at the archeological dig site and made shrinkage bars and test rings. All of the deposits were quite fine - very little grit at all, except for the glacial silt layer at the top. The Oxford clay (Jurassic period) was the only sample that needed work (crushing and slaking) before is became usable, but is a nice plastic, though not too sticky, clay. The river deposits were mostly usable as found, though two are very high in organic material and so unusable. These clays have varying amounts of fine silt in them and are generally highly sticky with a very high dry shrinkage.
I dried the samples, treated them with hydrochloric acid, washed them and dried them agian - to ascertain the calcium carbonate content. Oxford clay is high at around 20%. All the river deposits have some calcium content, though that for the 'buttery clay' and the 'rodden silt' seems lowish at 3 - 5%.

This image shows the tests fired to 1000C. As you can see, a few of the samples have developed such bad fire cracks that they have fallen apart - these are not the ones with the high organic content - but a few have held together and will form the basis for my next test mixtures.
I will fire these clays to 800C, 1100C and 1200C to see how they cope, colour and porosity. I will also be using these tests to help the archeologists ascertain which clays were used by the bronze age and iron age settlers here.
All this plus more biaxials and lineblends for a cone 11 glaze firing - I can hardly control my excitement!

New possibilities

Wow! Two posts in three days. Things must be happening (apart from the background hours of calcining, crushing and grinding).

I've been fortunate enough to be invited by the archeologists at Cambridge University to one of their dig sites in North Cambridgeshire, to investigate the various clays on site and (hopefully) give some insight into what was used to produce the various types of pottery found there. A slightly surreal place on the edge of the fens, where layers of deposition are removed one at a time to expose the ground level of a particular point in history. This drainage ditch was dug in the late bronze age.

I was able to see examples of the pots produced there, some of which were quite finely made and rather beautiful.

What was of most interest to me and this project was this section that had been cut through the ground exposing hundreds of years of deposition around the courses of ancient rivers. Many of these deposits are river clays, including the Fenland Buttery Clay, which I have been trying to get a sample of for ages.
The red/brown seam at the bottom is iron oxide, that has been dissociated from the upper layers, bleeding out from a very thin seam at the base. I have read about this occurrence and how it 'lightens' the clay deposits over time, but never seen such a fantastic example.
Back home now with many many clay tests to do. i am also going to fire some old pots shards to different temperatures to try to ascertain which clays they were made from.

A gentleman in Devon

Aah it's lovely to spend time in the South West, especially when the sun is shining and all around are signs of how damp it can be. I did some serious driving in the last few days - all along the caravan route to holidayland and then around the southwest. It's an interesting area geologically as there are the granite intrusions amid various sedimentary rocks, with the associated metamorphosis and mineral intrusions within the sediments.
The granite moorlands are impressive in the way that the fens of East Anglia are, but incredibly barren. The lack of trees depresses me after a while, and I'm always blown away by the stunning woodlands and rivers that run down from the moors.
Geologically there is plenty to collect: igneous rocks, limestones, shales and certain unknown stones. One of which, I have no idea what it is, but it melts to a stunning fluid glaze by itself at cone 10.

There are numerous old quarries, often flooded, that have a wonderfully impressive grandeur.
I also drove down to visit one of the china clay pits. The site manager was extremely helpful and I spent a few hours being shown around + collecting various samples. The most interesting are those that are not commercially viable, such as the mica deposits. There are a few grades of china clay excavated here, each washed down into the valley individually.

The clay filled water runs along the valley floor till it is sucked up into the separating equipment at one end. The sky was pure blue and I was surrounded by acres of white sand. Almost like my dream holiday destination. Give me a kiln, a wheel and a small country pub and I'd be happy!

Busy busy busy

It's been rather a long time between posts but I've been really rather busy.

This board of tests represents a weeks work! There's a couple of biaxials and some simple fusibility tests. The rest are progressive lineblends, building on previous results and generally incorperating more materials ie becoming more complex. I've spent much time massaging my wrists after serious mortar and pestle work. To releive the monotony I've been calcining, hammering and crushing other collected samples and testing various time lengths of ball milling , wet and dry, to get as 120 mesh sample. OK so it's not going to thrill all of you reading this and you'll probably have to imagine my serene faced satisfaction when holding a jar full of 120 mesh Mountsorrel granodiorite, but oh boy! what a feeling!

Ive also spent time at the geology department of Cambridge University running loss on ignition tests on samples of clays I've collected. I've also prepared samples for the more interesting sounding Laser Particle Size Analysis, and been preparing for my next trip. Off to Devon this coming week.

Back in Leicestershire

The best and most unanticipated thing about doing this project is visiting places, that I wouldn't usually see or spend much time in, in quite an intimate way - and meeting some great people, who are a wealth of information and actually interested in this rather weird thing that I am doing.
For the last couple of day's I was back in Leicestershire collecting more samples from previous test sites and from new places. The first image is Groby Quarry, which hasn't been mined for 15 years, just biding its time really until it is worth quarrying again.

Today the weather was far better and my clothes started to dry out from yesterday. I was shown around Beacon Hill by one of the rangers, who was extremely generous with his time and knowledge. It's the second highest point in the area and represents an exposure of the oldest rocks in England. It is a volcanic tuff, which was deposited in the pre-cambrian era.

Then it was a short drive to Mountsorrel, where there is a huge quarry, mining the slightly younger granodiorite. The woods around the quarry are full of these spectacular boulders.
It was also a chance to stay with Ben Brierley and hit the dazzling streets of Loughborough for a fantastic curry. Check out his blog http://ben-brierley.blogspot.com/

First results

So, this is what happens when you heat up parts of Leicestershire! Various igneous rocks here next to preliminary melt and glaze tests. Yes there's a lot of brown, but I think it's going to be a dark area. High in iron. But there is significant variation in the samples that I've collected.
The next image shows a biaxial from one of the darker rocks, varying quartz and dolomitic limestone.

The following images are lineblends from two of the areas I've collected from. Darker results from Leicestershire of course, but starting to get some subtler results including, would you beleive it, a blue(ish) celadon and a lovely deep green.
The clay tests didn't fare quite so well - I might photograph them once I've scraped/ground them off my poor kiln shelves!

Too much beer and then Ebay

Well at midnight after a few too many Fullers ESB's anything looks like a bargain! This little beauty caught my fancy. A cast iron corn mill. If only I had a tractor to run it from.....but I've cleaned it up and it is all set to become a fantastically useful tool in my future career as a rock crusher. I've tried it out manually(!) with some calcined granite and it's pretty good.
I haven't blogged for a while and it's because I've been busy creating a map of the Alps on my hands entirely out of blisters with a mortar and pestle making up series of lineblends and biaxials from the samples I got in Leicestershire.

Who would've thought that so much work could be reduced to such a small photo? Everything is loaded up into the test kiln and tommorow I'm doing a couple of consecutive firings - test reduction to cone 9 and a biscuit in the big kiln. I hope I don't get confused between the two!

Government plans to sell off our forests

Please go to
http://www.38degrees.org.uk/page/s/save-our-forests#petition
and protest about the government's plans to sell off our own country, the few woodlands we have left in England.

You know what we should do?

Get out of it for a while. Get into the countryside. Rejuvenate.

Rejuvenate! I'm in a park and I'm practically dead. What good's the
countryside?

.........it WAS cold, but once I'd got up against a radiator and covered myself in deep heat I started to recover.
It was a great weekend and I've come home with a car full of samples to test. The first photo is Grimley Andesite - well a stream full of it - and the second is a disused diorite quarry. Every view I look at now is stripped to the bare bones of its bedrock geology. When I close my eyes the stars I see are quartz phenocrysts. Maybe I've been out in the field too long........

Where did staggering around in fields get me?

.......apart from muddy knees and frostbite? It got me the unexpected! A seam of gravelly sandy clay deposited by a glacier thousands of years ago. And what's better, the icing on the potters cake, si that unlike the gault and everything else I've found it ISN'T full of calcium carbonate and therefore useable. Time to get off my knees and start seiving.......

Staggering around in fields

It's been a misty drizzly day today so I decided to spend it outside shuffling along the edges of fields on my hands an knees looking for half buried treasure. Potters treasure! As I sit here on the computer I'm chilled to the bones but feeling quite content. Very little in the treasure cache in my workshop but I think I've got access to a clay source that isn't contaminated with chalk (as the gault and other clays are).
My firing was a mixed bag but the positives are very strong. A couple of the materials I have found are stunning! What I'm actually going to do with them is another matter.........

Tests for the maiden test kiln firing

The kiln is finally ready for its first firing. Three days sorting samples, crushing and grinding and weighing and I've a kiln load of tests. The first is a selection of various collected samples from near my home - just plain fuseability tests - and then a few quick simple line blends to try and see what these samples contain. It's all a long way from a pot but hopefully it's a first step up.

More tests tomorrow then firing on Tuesday. The kiln's only small (40 x 40 inside) so it'll probably go up like a rocket.

Nearly ready to go.

The test kiln is lined and nearly ready to go. Just the door to bolt on, pyro to insert and the burner to fix on. Oh yeah - plus find somewhere to put it. Now to start preparing my tests. for the first firing. I've been collecting rocks form various locations, so plenty of grinding coming up for fuseability tests and maybe some initial lineblends. It's actually far more exciting than it sounds!

Test kiln

Decided I needed a small gas test kiln to I can fire all my tests frequently and cheaply. This is the frame - I cheated this time and bought Dexion. My welding is pretty dodgy + it kind of freaks me out. Always waiting to be electrocuted or blinded. So this is a breeze. Its going to be lined with fibre - I made the cups in November out of crank, alumina and molochite. I'll put up more info as I go.

New Year

Starting as I mean to go on............

Immersing myself in beauty and soaking it up.