Thursday, February 28, 2013

A very nice Raku day !

I finally got my act together and gathered all the pieces I have been hoarding for a raku firing. It was more than I thought, two kiln loads ! It took me a day and half to glaze it all. Revive the glazes, make new batches, apply, carve through, clean...It had to be perfect, of course. Which is rather ironic, since Raku firing is all about accepting imperfections :)

I reserved two pieces for Naked Raku and kept the rest for a traditional firing. I limited my choice of glazes to the (somewhat) usual: white crackle, glassy copper sand, a high titanium copper glaze, Irene Poulton's black, and a silver nitrate glaze.

First firing had the Naked Raku pieces and 3 other pieces. I fired to 1800 F in a little over an hour, taking the Naked Raku pieces out at 1400 F. Results below. Naked Raku turned out really good.

Naked Raku

Bamboos, detail view

Naked Raku

Bolted Vessel
Bolted Vessel, top view

Prosperity Vase
Chinese symbols for good fortune, happiness, longevity, spirit,
love, and endurance grace the vessel to channel positive energies.
Prosperity Vase, detail view

White crackle glaze

Wave, detail view

Second firing contained the three pieces that were treated with the silver nitrate glaze. The glaze has to be mixed in just before the firing to maximize the strength of the silver nitrate. People used to the chemical know what I mean. Exposure to light starts turning it black. Always wear gloves when handling silver nitrate solution. The way I do this, I premix the wet base glaze the day before, then weigh the crystals of silver nitrate, dissolve them in a small amount of water, and add the solution to the base. The solution thickens the glaze considerably, so I had to dilute it more with water. Next, the firing was done in about 1 hour. I had to go up to 1900-1950 F to completely melt the silver glaze, and I completed the firing with a 10 min reduction. Kiln got a bit too hot, glaze started to run off the pot. But, oh boy, beautiful effects ! Enjoy.

Metallic Vessel
Silver Nitrate glaze

Metallic Vessel, detail view

Silver Nitrate glaze

Flowing, detail view