Equipment

Doughmixer
Not many potters are still making their own clay, which is a sad state of affairs partly because it is the only way to ensure absolute consistency and partly because it is so much cheaper - why pay carriage on the water content? However, making your own clay does demand some serious kit - this old baker's doughmixer has a 3hp motor and weighs just over a tonne. It is driven by leather belts and was originally built in the year I was born - 1946.

Pugmill After doing the basic mix of clay in the doughmixer I run it all through a pugmill. This is a 3-inch pug which I have been using since 1970. I have replaced the original plunger with something far more substantial made by a local engineering firm. Although not a de-airing pug it does not seem to introduce air into the wads - its great benefit is that I can simply cut wads up into equal lengths which saves an enormous amount of weighing time.

Electric wheel I have two electric wheels - an early "Alsager" and one built by my father 25 years ago and recently modified by myself. I have nothing but praise for the Alsager and consider it to be the Rolls-Royce of electric wheels. It has made somewhere in the region of half a million pots and continues to be reliable. Years ago I had the original aluminium wheelhead inset with plate steel, which shows minimal wear; I also use a studded wheelhead when I am using batts. I tend to use the Alsager for wet work ie throwing, and my dad's wheel for dry work, ie turning. This simplifies cleaning.

Ballmill I have been using a ballmill for (mainly) glaze mixing for most of my potting life and find it the most efficient way of preparing glazes - pariticularly where glazes contain coarse-seived materials like wood ash or local clay. Although it looks crude it has stood the test of time and, if I was setting out to make one today I would use exactly the same design and materials. I do have a page about making a ball mill for those who may be considering going down this route. If you are a potter obsessed with glaze experimentation as I am, I would suggest some sort of milling device is absolutely essential.

Kiln In the very early days of my potting career I used a rank (3!) of 4.5 cu ft top loading electric kilns which, due to my output in those days wore out in three or four years. I replaced these with front-loading Kilns & Furnaces heavy-duty electric kilns of 10 and 12 cu ft. Since 1984, when I moved from Whitnell Pottery, I have used gas exclusively.

The current kiln is my third gas kiln and the second on its current plinth. The first gas kiln was a top-loader with three Ray Scott pot burners and was nothing more than a fireproof box with a lid. Although it worked fairly well there is, in my opinion, no subsitute for a "proper" downdraught kiln with an arch. The potburners came with flame-failure devices which I found to be the cause of flame failure rather than safety devices. I have abandoned the use of both external pot burners and flame failure devices - I am always with the kiln in it's first couple of hours and after that the inside temperature is such that flame failure is impossible.

Kiln rebuild The original kiln on the current site was built with high temperature lightweight bricks on the inside, Durox blocks on the outside as secondary insulation, and a framework of Dexion. It was OK but crude but, even so, clocked up around 300 firings.

In the summer of 2005 I rebuilt the kiln with the help of Paul Stubbs, on the same foundations, using the old inner-skin bricks as secondary insulation and J P Morgan 23s is the inner skin. These JM23s are nowhere near as good as the original lightweight bricks (K23s I think), in fact I consider them to be so poor for stoneware temperatures I would actively NOT recommend their use. The main problem is hot-face shrinkage; bad in itself as huge gaps open up; worse as there appears to be some sort of internal thermocline which results in the bricks splitting longitudinally. The problem with these bricks is so acute that I shall have consider a further rebuild after about 50 firings.

Burner ports All that to one side; perhaps the most interesting part of the story is the burners. I wanted absolute control of the flames and believe the only way to achieve this is by using internal burners. And this, of necessity, means they must be ceramic. The solution was straightforward and cheap. Nothing more complicated than an 11" kiln prop with a flame spreader drilled out with a fine masonry drill. At the gas end a fitting which is much the same as for pot burners. And internally, under the burner, a secondary air port with slider control.

Burner As can be seen from the picture to the left the burner is, indeed, a drilled-out kiln prop. The picture above shows the burner ports with the primary gas control and, underneath, the secondary air port with a slider to control airflow. Hot gases within the kiln are drawn under the floor and out through two exhaust ports (with sliders made from 1" kiln shelf acting as dampers) by the pull on the chimney, which itself has two air ports with sliders to allow varying amounts of cold air to be introduced into the chimney, partly to control the "pull" on the kiln and partly to prevent overheating.

The kiln shelves are all 13"X13" and I usually pack the kiln as tightly as possible with regard to gas-flows. At top temperture the difference between the base of the kiln and the top of the arch is about half a cone - quite acceptable, and I tend to use the top layer for glazes with very slightly lower maturing temperatures.

Updated 5th February 2009