Happy Faces Last Night

Our second and last firing of our summer independent study class was amazing to say the least. As we unbricked the kiln last evening, we could see the results of the firing -- wonderful!!! This time we got the body reduction we wanted as you can see in the toasty, warm coloring of the pots. Here's a preview. More pictures and video will be coming, as well as, our firing log.

The kiln after unbricking, the top shelf, another shelf, the bag wall refire piece, our faithful kiln gods...and celebrating at the Mecca!

Results of our First Kiln Firing and the Firing Log

We met on Tuesday evening to unload the kiln. Unfortunately, our results were not what we expected from a typical 'good' soda firing. Our pieces looked anemic, lacking color and richness. The glazes did not flux as they should have. Our immediate conclusion is that we didn't really go into Body Reduction like we thought we did. I'll post pictures of pieces later. For now, here is the firing log. I've highlighted some key areas in red. After some discussion about what contributed to our not so great firing with PNW instructor and soda fire expert, Damian Grava, we added notes to our log and instructions on what to do next time...Click on the picture to get a larger view.

First Kiln Firing

The first kiln firing went smoothly and without any troubles. I will post our kiln firing instructions in the next posting. We agreed to meet at the studio at 7AM since we were anticipating a 12-15 hour firing. We lit the kiln at 7:40am and proceeded to fire until 7:55pm. We did a body reduction for about 1/2 hour and spray a soda ash mix for about 1 hr 20 mins. I'll be posting our soda mix recipe tomorrow. Take a look at our soda spraying video, thanks to Hilary Chan for taking this video.

Loading the Little Soda Kiln

We loaded the kiln on one of the hottest days this summer in Seattle. It was much cooler indoors than outside in the kiln yard. It didn't help that the sun at 4pm happened to be blazing on the Little Soda kiln. We perservered and finished the loading by 8pm or so. Stacey and Orla bricked the door this time around. We had more pots than could fit in the kiln. They will get in the next firing.

Bisque Firing Notes

Here are some pics of the bisque kiln. We filled 2 kilns: New Oly (manual) and Mike (programmable automatic).

Here are the steps we followed for New Oly (manual kiln):

1. Insert on 06 cone in the shut off ledge.
2. Load greenware in the kiln.
3. Remove peeps, close the door and prop open with heat proof brick, press the ON button and turn all 3 knobs to LOW for about 2 hours. 4. Remove the door prop and cook for another 1/2 hour or so at LOW. 5. Insert the peeps and turn the knobs to MED for 2 hours. 6. Turn the knobs to HIGH for 2 hours. 7. The kiln will shut off automatically when the temperature reaches cone 06. The cone curling will trip the switch to turn off the kiln. 8. The next day prop open the kiln door with a brick. 9. When cool, unload the bisque ware.
As for Mike, the automatic kiln, it is programmed to heat to cone 06. You merely have to push the start button. There are no peeps to worry about. One additional step that all of the automatic kilns have is to turn on the ventilation. You will see tin ducts behind these kilns and a switch to turn on. Wally, the studio director, assisted in using Mike. We wanted to pre-heat (candle) before we started the full on bisque because we knew we had a few wetter pieces in there. He helped with setting it up to pre-heat for about 4 hours before kicking off the normal bisque process.

First Kiln Firing Schedule

Here's our schedule:

1. July 17, Mon: Stack and stage greenware in bisque room.
2. July 18, Tue: Load and fire bisque kiln (New Oly & Mike). Orla, Virginia
3. July 19, Wed: Unload bisque kiln. Stacey, Leandra
4. July 20-21: Glaze, glaze, glaze.
5. July 22, Sat. 4:00PM: Load little soda, clean shelves, etc. Everyone.
6. July 23, Sun. 9:00AM: Start firing. Everyone.
7. July 25: Unload kiln.

Our Studio Space

Here are some pictures of our studio space, including greenware shelves and storage.

Soda firing

One of the unique features of the Pottery Northwest Studio is that it has 2 operational soda kilns fueled by gas. What is a soda kiln? A soda kiln is a kiln that is very similar to a standard kiln; however, it has several access points where you 'spray' the soda mixture into the kiln. What is a soda firing?

Soda firing is an atmospheric firing that produces flashes of color, maybe a textured orange peel surface, and reacts in a variety of ways with different slips, glazes and clay bodies. The “soda” in soda firing is typically a combination of baking soda and soda ash. The soda mixture is introduced into the kiln near the end of the firing, once the kiln has reached a certain temperature. The soda vaporizes and is carried on the flame throughout the kiln. Wherever the flame travels, the soda travels and reacts with the pieces in the kiln to create a glazed or flashed surface. For this reason, it is common to leave some part of your pottery unglazed.

In our independent study class I would like to explore:

1. the effects of soda firing on different clay bodies, e.g, shop soda clay, autio, etc
2. the effects of location of pieces in the kiln with respect to the spray holes
   
3. the effects of slips, glaze, terra sigilatta in a soda fire, perhaps creating specific slips with a result in mind, e.g., copper slip
4. the affects of atmosphere in clay bodies, e.g. amount of soda and oxygen

We have read Gail Nichols article from Ceramics Monthly wondering if we could apply some of her ideas to our firings this summer. Time will tell.

This is US!

There are 5 of us in the Indy class: Chris, Leandra, Orla, Stacey & Virginia. Here we are celebrating 4th of July at Fionnuala's, near Gas Works Park.