Raku kiln, version 2.0

New Raku kiln

Bye, bye metal trash can, you've been replaced for a nicer, fancier model. Soft bricks rings to modulate the height according to pieces. Light top out of ceramic fiber for easy lifting, and a big flue to take small pieces through. And a huge space inside ! 23" diameter, great for large platters.

I took it out on a test drive last week. First ride was a saggar firing, baked potato style (see former post). Firing was done in an hour to 1400F, then I shut down the gas, plugged the holes and let it cool down naturally. It took about 4 hours to 250F, I unloaded the next morning. Aluminum foil had disintegrated to leave wonderful orange/red pots.

Square Bottles

Vase with australian fern imprint

Second ride was a regular Raku firing. I placed several pieces with crackle and copper glazes, as well as a Naked Raku piece. Again, the firing went well. I took out the Naked Raku piece at 1350F, after 45 mins, then I proceeded to increase the temperature to close to 1850F in another 20 mins or so. Venturi burner could definitely handle the kiln size, that was the true test. I am very happy with the results. Here are two of my signature Orb series.

Crackled Orb

Shadow Orb with pedestal

Ok, back to the studio ! I need more Raku pieces. I am all fired up ! :)

   

First load in the electric kiln

Very, very pleased with it ! After several rounds of glaze testing, it was time to jump the shark and apply my favorites on real pieces. I have had my electric kiln for a while now, mostly bisquing for Raku projects. Now that I think of it, August is its one year anniversary !
I started out with some old porcelain pieces I had around, made with Hagi porcelain. It's a nice porcelain to handle. The test tiles I did with it all came out better than with the cone 5/6 stoneware, for some reasons.
One of my favorite glazes so far is this red yellow speckle glaze I picked up in Book of Glazes from Emmanuel Cooper. Absolutely stunning, with reddish/brown crystals on a light yellow satin background.
Another glaze I was excited to use was a manganese crystal glaze that I adapted from a cone 10 glaze, using Digitalfire Insight software. I made two variations and they both turned out like the cone 10 glaze we use in reduction gas firing at Clay Associates studio. The tiny crystals create a deep shiny surface with a dark chocolate hue.  Definitely a keeper !
The top and inside of the floral arrangement vase consist of a layer of a clear red/black glaze followed by a layer of a rutile glaze called broken pearl to give an opalescent tint to the piece. You can see that the glaze picked up a bit of iron by the blue breaks on the inside.
The clear red/black glaze is more of a clear honey color, as seen in the bowl set. Very consistent glaze. When thick it becomes a darker brown with light gold specks. Here the bowls were sprayed with a medium application. I added a medium spray of the spearmint glaze from Roy's Mastering Cone 6 Glazes book, mostly concentrated around the rim. The effect is more muted than I envisioned. I can try dipping the rim next time.

7" high porcelain bud vase;
electric, cone 6;
red speckle yellow glaze

6" high porcelain wide rim vase;
electric, cone 6;
red speckle yellow glaze

4.5" high x 7" wide porcelain floral vase;
electric, cone 6;
clear red/black glaze, broken pearl glaze,
 manganese crystal glaze

4.5" high x 7.5" wide porcelain bowl set;
electric, cone 6;
clear red/black glaze, spearmint glaze