Playing with Raku

I've hardly done anything this last couple of weeks, it's school holidays so my time has been dictated by children. So I was looking around for something to write about and I decided to have a go at a raku technique I read about ages ago.... resist erosion.

Raku Firing

I've tried this idea on porcelain once before using shellac to mask the design, but this technique uses wax. I had a bottle of wax resist and a piece of dry greenware that I made to try out slab building that I didn't know what to do with next so I started of giving it a coat of wax.

Greenware with wax resist coating

You can't see much from the photo, but it's fully covered with a coating of the resist.

After tracing around the edge of the shape, I sketched out a rough design and transferred it to paper which was wrapped around the piece.

Transferring the design

The design was traced over again with a ballpoint pen and a gentle pressure to transfer the pattern on to the clay.

Scratching the design through the wax

Using a sharp pointed tool, the design was scratched through the wax and in to the clay. I freehanded some leaves and grass to fit around the shape.

Sponging away the clay

Using a sponge and gently rubbing in a circular motion, I carefully went over the lines to wash away the clay. The wax starts to erode along the edges where the design has been scratched through to the clay leaving a shallow organic depression in the piece. 

Glazing

Once the piece had dried again, I painted over the lines with a copper glaze. The wax resists the glaze and any pools were removed by gently dabbing with some kitchen roll. Once dried, it was put in to the kiln for a single firing. 

The reduction bin

I couldn't photograph the next bit as I needed both hands for taking the piece out of the hot kiln. It was transferred using tongs to a tray of sand with straw and newspaper on top. Once alight, a metal bucket was placed over the top and pushed in to the sand to create a seal and allow the oxygen inside the bucket to burn out creating a reducing atmosphere. The lack of oxygen affects the glaze and brings the metals in it to the surface.

The big reveal

After a few minutes, comes the exciting part... removing the bucket and seeing what the flames have created. 

The finished piece 

Not so pretty on the back

The muck and carbon were cleaned off and I gave the piece a coat of clear sealant for protection. The front and back look totally different, mostly due to the fact that I messed up the cleaning on the back bit during the glazing part and rubbed it rather than dabbing, so the glaze got stuck in the wax and transferred to the parts that should have stayed black. 

Overall though, I'm pretty happy with how it turned out. It's much better than my first attempt at copper glaze where everything just came out nasty brown, and it's definitely something I will be exploring further. I think this would be a fantastic technique to try out on beads!

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