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Gilhouse Pottery Blog Post


Raku Like a Hurricane

In early November of 2022 I was thrilled to be invited to participate in a raku firing and squealed when I heard I could bring a piece of my own to fire. I've found myself admiring raku pottery and it's been in the back of my mind to someday add this method to my skillset.

Quickly and summarily, Raku is an alternative firing method for pottery where bisqued pottery is quickly brought to 1000°F - 1800°F in an outdoor gas fueled kiln. Once the desired temperature is reached, the piece is removed while it's very hot and then a variety of techniques are used to shock the surface creating finishes that are like no other kind of pottery. It's thrilling, unpredictable and requires the acceptance of loss because often the piece does not survive the process. An experienced raku potter accepts about 25% loss.

I learned when we arrived that we'd be doing two methods: Obvara and Horsehair/feather carbonization with ferric chloride finish.

Obvara Vase
Obvara Vase

Our host, Lee, went over the processes thoroughly and pretty soon it was time for the four of us to jump in. I first took on the fairly simple task of operating the kiln door while a fully protected Lee reached into the 1400°F kiln with tongs to remove a pot. Over to the Obvara bucket the three days fermented solution of water, sugar, flour and yeast was poured over the pot while Lee turned it. Once satisfied, the piece was dunked into a bucket of water and set aside to cool further. When cooled, the pieces were covered in a slimy and burnt film of material. We all touched them to experience the texture. Next, the slime and carbon were scrubbed off with a common kitchen scrubby and that's when we were able to appreciate the true reaction and texture.

The resulting surface showed beautiful shades of light brown to black with varying patterns of blotches, veins and spots. Some areas looked like wings while others looked like worm wood. I quickly appreciated the unpredictable and mostly unplanned effects we were achieving by controlling the pour rate, the different ways the solution reacted if the piece was cooled a bit before pouring, as well as how quickly the dropping temperature affected ability to be finicky. There certainly is a degree of art and experience combined to get a desired effect but it was largely out of our control. Thrilling.

In all we fired about 15 pieces Obvara and lost two which is below the 25% loss rate so basically we killed it.

horsehair feather ferric chloride raku
Michele's Jar

Next was horsehair, feather and ferric chloride. These pieces were only (only!!!) fired to 1000°F and held for a little bit to try to maintain the heat for a little longer after they were removed from the kiln. First a little bit of granulated sugar was sprinkled on which resulted in cool black spots. No time to stand and marvel over that because next horse mane or tail hair was draped onto the piece where it instantly crinkled and burned leaving a permanent carbon impression on the surface. Finally the feathers were placed on the surface where they too burned and left a feather like impression. Newspaper was added inside the piece which ignited and changed the white clay to gray/black. Lee fitted himself with a respirator while the rest of us stood back and upwind as Lee sprayed the ferric chloride. Initially the piece showed a yellow hue which quickly turned amber to red. Color variations were created by more or less solution sprayed. The finish was stunning and it was exciting to watch the transformation occurring. No water dunk for these pieces, we had to wait patiently for them to air cool before they could be moved for the next piece. These too are scrubbed lightly to reveal the design.

The final touch is to seal the work with wax or a clear coat of polycrylic. I've opted for wax. Please don't be misled by my use of the word "seal", for raku pottery is decorative only and is not suitable for functional work that would be used for food or drink. We're simply protecting the finish as well as giving a light sheen and silky surface texture. Ok, so you could use raku for a fruit bowl if you really wanted to.

Between the firing, the potter's socializing, the show and tell, a few hours had passed. Riding away I felt exhilarated and yet emotionally tired. I'd found myself invested in each piece and the drama of the experience was tiring. The excitement, the urgency, the caution and the relief a rollercoaster ride of emotions, over and over. Strangely I was the least concerned about my own work.

Lee generously gifted me one of his Obvara pieces and the piece I brought was done with sugar, horsehair, feathers and ferric chloride and so I now have cherished mementos of my first experience in raku firing. I fear I may never be the same.

I've created a compilation of some of the scenes from that day, but all involved were so focused that recording video was not much of a priority. I hope you enjoy it anyway.

Lee Halweg's beautiful raku work is available for appreciation and purchase at Harbour Honest Goods in Oconomowoc, WI.

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