Building upper body strength

As the rain seemed to have stopped for a while I made the most of being able to work outside preparing wood (splitting by hand as my wood splitter has frustratingly burnt out its electrics) and rocks for my next batches of glazes.
The kiln was lit for a slow bisque. Muscles tensed, I approached the steel mortar and pestle with buckets of calcined rock.

I break up the rocks into manageable sizes with a hammer before calcining them in my gas test kiln. Then, using this mortar and a 1 1/2 inch diameter steel pestle, I crush them down to 8 mesh (around 2.5mm max diameter).
Calcining works best on igneous rocks with large crystals like Dartmoor granite. Unfortunately for my arms I had fine rocks such as Arthurs Seat basalt from Edinburgh.....

.... a triassic sandstone from Martley in Worcestershire, Pentland felsite and a metamorphosed granite from the Malverns that has separated into  thick swirls of quartz, feldspar and mica.
This  collection of buckets took me 4 hours and is now ready for the ball mill.

3 hours of milling and the grit is reduced to a fine dust that will readily pass through a 60 mesh seive, with about 90% through 100 mesh. I used to mill finer but find that  this slightly coarser grade gives good results.
The red lidded jar is 2/3 full of hard alumina balls, which tumble as they rotate, crushing the rock. I am milling most of the rocks dry....

...though I mill quartz wet for the best results, and to keep the dust down as I need this very fine. Here it is settling out (which takes about 24 hours) before it can be slopped onto a plaster batt to dry.










 For some reason I am unable to reply to comments on my post so......
Hi William. Don't mind at all. You can certainly use it to make a glaze. Try using it to replace the feldpar in one of your usual glazes or do a lineblend adding whiting and some clay. Good luck!

Hope I screwed the corrugated iron down well......

....the kiln is lit for another very slow bisque firing and the shelter I have built around it is rattling in these violent winds. I'm relieved  slightly by my choice in extra long hex head screws when I built it + by the fact that all the burners have flame failure devices on them.                                                                      

The last of the clays that I have made up have been used. This image shows a kaolin and ground quartz body from Dartmoor materials. It is the largest piece I have made from this body, being 38cm tall, but had to be made in 5 sections as the clay is so difficult to use.

Now all that is left is to make the setters and lots of testing.

The first set of tests, pictured here, are more lineblends of Malvern rocks. I'm still trying to get a good glaze out of the Precambrian diorite, which seems to me to be closer to a dolorite in its lack of silica. I'm blending a Triassic sandstone into the glazes to try and get a good melt.
Other tests include lineblends of materials from the Gog Magogs near where I live. The rocks and silts are glacial deposits + I am trying to get a beautiful glaze out of them for a commission. So far it is proving elusive, but if there's one thing a potter needs it's optimism!

Heading to the dark side

Drill out! Whizzing up buckets of slaked crushed secondary kaolin and covering myself with it as well. It turns to slip pretty well after I fish out the larger stones. Then it all goes through at 60 mesh slip to remove the bits of limestone that are unfortunately part of the grit that's in it.
Then plenty of its own grog added, plus grit (mostly quartz with some mica chunks) from degraded granite, stiffened up on plaster batts and, after extensive kneading, it is ready for action.

I've been making a few different forms from it, including some larger composite pieces. It's not that plastic but OK to throw as long as I don't attempt anything over around 30cm.






Most of the pieces that I am making at the moment are starting from fairly simple forms like these.....

....and getting altered and cut once they have stiffened up.

You can see the iron in the body and fired in the wood kiln it tends to come out a dark burnt chocolatey colour with orange flecks where more protected. It is a great contrast to pale glazes as can be seen in this piece. It is also very good with a fluid type of Dartmoor granite glaze, where the iron bleeds out of the body into the glaze with quite spectacular results.

Wet as a...well, a Sunday in England.

This is the view from my windows and it is relentless. the ground is saturated and slippery (full as it is of smectite clay crystals) making the walk to the kilns with a board of pots rather perilous. It's also interfering with the outside work I have to do, such as crushing clays and rocks. Only one more clay body to make up though - a dark firing, highish iron body from the East Dartmoor secondary kaolin. It is quite difficult to throw and extremely prone to firecracking in the bisque, so I have made a good sized bucket of grog to add to it and will take the bisque very slowly, especially around 300 - 700C.
Tomorrow, though, a long drive as I'm off to the Malverns to collect some more mudstone samples and give a short talk to the Teme Valley Geological Society
I 'm taking samples relevant, to the area including this...

Fired up in the front of the kiln - you can see the base was sat in the embers - it is glazed with a relatively refractory metamorphosed, high silica, felsite.
The mudstones I'm collecting are among the oldest clays I have got hold of and I will be using them for a high earthenware firing in my small wood kiln.

Wet, green, moss and ivy covered wood

One good thing to come from the recent high winds, for me at least, is that a few trees have come down and I have had a delivery of logs. This very wet pile is cherry, sycamore and some elm. I've stripped it of most of the ivy and will cover it so that it can season for next year. It seems strange to be thinking of 2015 already, but I have to plan my wood supply well ahead.

After a few weeks of planning, drawing, writing and taking photographs it is a REAL pleasure to get back in the workshop, making for the next firing. After so much time spent in the abstracted world of thought my immersion in the physical world of matter and action is startlingly refreshing. In my workshop with my hands in the clay, music playing, alternating sleeting rain and low slung sun dazzling through the windows, I couldn't be happier. That must be why I love woodfiring. So much in our lives is abstracted away from our direct experience or done by machines that we risk losing touch with our relationship to the Earth. This whole process that I work with, making things from clays and rocks that I have collected and processed myself runs contrary to that, and woodfiring insists on total commitment to the physical here and now.

Winter sun

It's a beautiful winters day - clear blue skies and above freezing - so hopefully the ground and my woodpiles will start drying out so that I can start sawing and splitting wood.
I'm back in the workshop having finished the article I'm writing for Ceramic Review on my firing with Svend Bayer.

 I've also finished grinding all the successful work from the firing and have taken photographs of it , so I thought I'd put some up here.
This large platter is glazed with rocks from Edinburgh, including Arthurs Seat basalt.

This one is glazed using the oldest rocks in England - over 700 milliion years old. They are metamorphosed igneous rocks and Silurian limestone from the Malverns in Worcestershire.
The rocks seem to be quite weathered + so much more refractory than I would have expected. This glaze needs to be placed in  the  hot spots of the kiln.

This piece is glazed with rocks from Cumbria. I'm aprticularly pleased with this as it has captured the somewhat fleeting qualities that can be got from these rocks really well. The glaze is highly varied: aqua, electric blue and purples with white crystallisation.

These last are made from Dartmoor materials with a very dark body made up from an impure secondary kaolin.

Smashing New Year Grog

Ignoring the weather, battening down hatches and sheltering the burner with kiln shelves, I'm hitting the ground running in 2014. I have one of my clay bodies made up ready to use but am still working on some of the others, most of which have to be opened out with grog. This is smashed, crushed and seived from a high alumina refractory clay I have.

I fire this up over 1000C - just enough to bisque it, remove all plasticity and calcine any stray pieces of limestone that are (unfortunately) in it. As long as this happens the pieces teun into calcium oxide and do their expansion and crumbling up when they are added to the wet clay (rather than when glaze fired!)

A lot of the clay I use is highly compacted and very hard. This is one of the few clays I have found that I can use almost as it is, with no additions - though it needs a lot of work with the hammer before adding water to slake it down. I have managed to dry out these clays, which makes them easier to slake - no mean feat in British weather!

The final Clay For Today is this unpromising gravelly looking stuff. It is a crushed and slaked carbonaceous ball clay that actually fires quite white when all the carbon burns out. At the moment it feels completely non-plastic but with a lot of kneading it becomes quite a reasonably useable clay.