A Good Firing of the Wood Fired Kiln!

We fired the wood fired kiln on Tuesday of last week and it was a great relief on Friday to remove the door bricks and discover that it had been a good firing. We have had days of hot weather here, and the 10 and a quarter hours of getting to temperature had been rather arduous. I drank about 2 litres of water through the day whilst stoking, and also had several cups of tea!

People sometimes ask me "if it feels like Christmas" when I open the kiln. I was thinking about that when I opened it this time and I realised that the process of wood firing is much more like Easter. There is a real ordeal involved in the firing of a wood fired kiln. A week or so of glazing pots, packing the kiln, and chopping wood, and then the intensity of the hours of the firing itself, followed by a nearly three day wait for the kiln to cool after temperature has been reached. Removing the first bricks from the kiln door is usually done in the stillness of early morning.

My thoughts, as I removed the door bricks, were of the women arrived at the tomb early on the first Easter morning who found the stone rolled away!

Jugs
I was greatly anticipating seeing how these jugs turned out. They were made with a clay that I am testing at the moment that had showed great promise in the tiny samples that I had put in the previous firing of the wood fired kiln and in the electric kiln. The jugs were the first "real" objects that I had made with the clay, and I was anxious to see how it would cope with the realities of fire and flame and very high temperatures. Happily it performed beautifully, and the clay has a lovely warm colour where ever the fire hits it directly.

The jugs are between 6 and 7 inches high (152 - 178mm) and have a shino glaze inside.

Porcelain Bowl
I tested a rutile glaze in this porcelain bowl. The bowl had an iron bearing under glaze on the inside only. The glaze gave pretty pinks, blues, and violet shades on the outside, and an exciting waterfall of blue flecked with cream, pink and brown on the inside! The bowl measures 4 inches high by 7 1/2 inches wide (102 x 190mm)

Pouring Bowls
I made some pouring bowls, and enjoyed the playful form, with the pouring lip and eye embellishments. I tried various glaze combinations.

The pouring bowls are approximately 4 inches high by 6 in diameter (102 x 152mm).

Runny Ash Glaze
I like glazes that don't just sit still when they are fired, but sag, pool or flow. Wood ash contains silica and useful fluxes that include potash and calcium and traces of other minerals too. Ash will make a glaze all by itself if applied to a pot, but improves if other things are added to it, such as clay and feldspar. Containing just 15 percent of unwashed wood ash, this ash glaze has so many "other things" in it, that it is called a "fake ash" glaze. It is Van Guilder's "fake ash" glaze from John Britt's Cone 10 High-Fire Glazes book. Flowing over a white matt glaze as it does here, it has the look of a spreading wash of very wet watercolour.


The bowl measures 7 1/2 inches high by 9 inches wide (190 x 228mm). The ash glaze was applied to the top quarter of the bowl after the white matt glaze had been put on. I was interested to see how the ash glaze ran further where it got the most heat.

Strontium 
Strontium gets its name from Strontian, which is a town in Scotland where this alkaline earth metal was first discovered. Strontium carbonate behaves very like calcium in a glaze, and can replace it in glaze recipes and is superior to it in some ways, however it costs a lot more, so it is not commonly used. One property that it does have that makes it useful on "special occasions" is that it does assist in producing some lovely alkaline blues from glazes that have copper in them. It is almost as effective as barium carbonate in this regard. Strontium carbonate sounds like a deadly chemical from the nuclear industry, but Strontium carbonate is non-toxic, it is the isotope Strontium-90 that is dangerous, and this is not what we are dealing with here!

This 7 inch high (178mm) jug has a glaze on the outside that contains 4 percent copper carbonate and nearly 32 percent Strontium carbonate. I love the scatter of dark crystals where the glaze is thick. The glaze recipe comes from an article in Ceramic Arts Network Daily, leaving bariumville replacing barium carbonate in cone 10 glazes. The inside glaze is a reliable tenmoko type glaze.


Toasted!

 

I sieved wood ash and feldspar directly onto this stoneware pot, and left it to the flames to make a glaze of it. I like the texture where the feldspar has melted with the wood ash. The pot is approximately 10 inches High by 10 inches in diameter (253 x 253mm).

Angelic Musicians!
Christmas is almost here, so I made a merry group of Angelic Musicians who play together on a variety of heavenly instruments that bear some similarity to earthly saxophones, trumpets, and medieval instruments. The musicians range from 4 to 5 inches in height (102 - 127mm).