Bourry box kiln

I spent some time today feeding eucalyptus bark into a wood fired kiln my sister-in-law has made. They started the firing at 5am will probably finish about midnight. I've never seen a wood firing in person and found the process fascinating. Manipulating the amount of air in at various places , the size of the fires and the rates of heat increase was a continuous fine tuning.

Wonderful stuff!!!
Though I've not seen side feeding of bark before and wonder what effect that will have on the pots.

What has happened with that particular bark before is that a charming blue has formed on a particular glaze. This is only the second time this kiln has been fired and the hope is that this blue will appear on more pieces that have been stacked near the port I was feeding. The potter was making detailed notes of the firing process in the hope that in later firings the kiln god could be enticed along certain pathways. I looked through various ports into the belly of the beast and saw swirling spiralling flames racing to leave their mark.

So I picked up my bowl today. It has some nice effects which flash does not do justice to. It's a white stoneware body with a shino glaze inside and down the outside a little too.

Shino goes orange when there is a reduction atmosphere, so perhaps your lovely little bowl missed out. I do like Shino even when it is white and ink it to show off the crackle.
Nice bowl Tony!

From last Sunday's firing - the third for this kiln. Unpacked on Saturday 7.11.2015



The inside of the kiln:



The fire box from inside the firing chamber:



The kiln during the previous firing - one of the side stocking ports has bark sticking out of it and you can see the ends of the rods holding the first layer of bricks that make up the roof:



The roof of the firing chamber stacked ready for the next firing. Rows of bricks with threaded rods holding them together. These are placed on the top of the kiln, another layer of bricks added, and then any gaps filled with mud.

Tony,
Is the "charming blue" from the bark the same chemical that puts the haze on the Blue Mountains?

The haze is eucalyptus in the air but I don't know enough glaze theory to know if the colours produced are species specific. There are over 500 different eucalypts which may give a broad or narrow pallette under oxidation and reduction firings.

My linseed oil and beeswax decorated pot standing out in the packed kiln. The firing has been put off a week to avoid the deluges forecast for this weekend.

My pot is sitting on a bed of rice husks and its more subtle kiln mates have shino glaze, wood ash or are unglazed.

The wood ash glaze Jen Lyall used was made from eucalypt bark reduced to ash and then sieved and made into a thin slurry. Be interesting to see how it turns out.

I helped with the stoking of this modified Bourry Box kiln on Saturday. The fire box was originally right next to the firing chamber but the potter rebuilt it with another firing chamber like a train or coffin kiln one between the two.



The main chamber has a trolley system with a turntable so that it can be run on rails into an adjacent gas kiln.

The end of the trolley becomes a kiln wall pushed into ceramic fibre. There is a turntable under the trolley's bottom shelf/kiln floor. Much of Rosewitha Wulff's workshop was built by a Ceramics Department technician and potter who worked with her when she taught at St George. The fire box lid is raised/lowered on a counterweighted pulley system and the arched roof of the middle firing chamber is also on a pulley system.

Thanks for sharing that Tony.


That looks like a steel frame door for the wicket, integral to the trolley. How sensible for loading.


An earlier Quarry kiln design had the extended throat arch like this. Having had work fired in the throat arch I only now see the advantage of such a system for creating effects just a bit closer to what is achieved in an anagama kiln. I'm still grinding clinker off my mug as our throat arches as built are only two bricks-lengths long and there is some spill from the ash box.


I have been looking at Greg Barron's wood kiln, yet another bourry box, on his facebook page. I remember it being very neat from a visit there but I have learned a bit more from seeing the pics of its construction. His chamber arch is a thing of beauty.

It seems that the throat arch has in some Bourry boxes become the only firing chamber and the main chamber done away with. I think these are known as train kilns or coffin kilns. Greg Crowe prefers firing in this middle chamber as that is where the most dramatic ash build up occurs. Rosewitha builds up a bag wall of narrow tightly packed ware shelves between the throat and the trolley. In theory by the end of the firing flames would have been comin out of the chimney two metres or so above the roof. There is a viewing slot in the chimney inside the workshop with a sliding door possibly made from a kiln shelf on another pullet system so the flame can be seen without having to walk down the driveway.

The group I woodfire with is having an exhibition early December.

An exhibition piece created by movement in the kiln. A shino glazed pinch pot of mine locked in an everlasting smooch with a wood ash glazed test pot by Judy Boydell.