Tuesday, May 24, 2011

Wood Fired, Salt Glazed

Here are few pots from the last wood firing.





Blue No Blue

Glaze testing. Recipes for glazes are everywhere. Just goggle. Or buy a great book like John Britt's "The complete guide to High-Fired Glazes" and you find pretty pictures and the listing of materials that if combined and applied will lead to beautiful pots. And they often do. But, somewhere there is fine print which basically says: "Your results may vary..." There are multitudes of reasons for this. The materials differ from mine to mine or even different locations in the same mine. Your application isn't the same. You don't follow the exact same firing schedule. Etc. Etc. So you do tests. As I am in search of my "style" and body of "coherent work", I try to put glaze tests into the kiln when I fire.

Recently I had the opportunity to do back to back firings in my gas fired Soda Kiln and then in my friend, Rob Harvey's, wood fired Salt Kiln. So I made duplicate test tiles for each kiln. The clay used was a stoneware made by Highwater Clay of Ashville, NC called Orangestone. The results were interesting and are shown below.





















Okay, so? Well, they are different from kiln to kiln. Surprise? No. They are different from Soda to Salt glazing. Surprise? No. They are different from gas to wood fired. Surprise? Again, no. The tests also failed to find a nice blue. Lots of green, but blue? No.

So was it worth doing? You bet. I got two glazes that are working in both kilns right out of the box, Emily's Purple and Gold Shino. Plus a couple more that may work with a little more... glaze testing.

Wednesday, May 11, 2011

Results

"Dude, that was an extreme sauna!!!"



Here is how the face jugs turn out.





And a few other occupants of the kiln:









I try to put in glaze tests in each firing. I had 8 in this kiln. Out of those, two are definitely keepers.



Are here is what they look like on some pots.





Sunday, May 08, 2011

Cool Waiting



I was just out peeking in the spy holes. The pyrometer is reading 540 degrees still so it is going to be a while. The rule of thumb I was given was that if you could stick a roll of paper into the spy hole and it didn’t burn or smoke, you could open the kiln. [Fahrenheit 451 for Ray Bradbury fans] I have done this, but found the “Ting Ting Ting” sound of the glazes crazing just too nerve racking. So, I go a little slower…

The process of the firing seemed to go well. I did it a little different this time. I have been starting the pilot burners at 10 or 11:00 pm the night before and letting them burn until I get up the next day and light the main burners. The kiln would reach about 450 degrees. This time I just left it until the morning of the day of the firing. I lit the pilots let them burn an hour and then cracked on the mains and let them burn an hour. From there I boosted the pressure 1 psi and hour until I reached 4 psi. I set then damper at 5 inches open and it is in cruise control. When Cone 010 goes down, I pull the brick out of the passive damper and let the kiln go for an hour in body reduction. Usually Cone 080 goes down during this. Back in cruise control the kiln climbs towards Cone 10 (~2350 degrees). I finished up maybe an hour later and saved a few bucks.

It is then time for the fun. I mix 3 gallons of hot water with 3 lbs. soda ash, 1 lbs. salt and ¼ lb. borax. I put this in a sprayer, open ports in the kiln and spray.









When Cone 10 goes down, I shut the burners off and let the kiln cool until 1900 degrees. At this point, I relight the burners and hold that temperature for an hour to foster crystal growth in the glazes. This adds depth to their color if I can get it to happen. The whole firing process is like that. You try your best to control it, but in the end, the kiln Gods give you what they want.

Friday, May 06, 2011

FiringToday!



I swear as I was bricking the door, I heard this voice: "Help, Help! I am claustrophobic!"

After many delays and lots and lots of rain, Cone 010 is down and the kiln is in body reduction. Yea! And I have stuff in the Rob's Wood kiln ready to fire next week. And I have half a ware cart full ready to glaze.

Biggest news is that I have actually sold some pots. ART a la Carte is showing my work and sold some pieces! Not making a profit as yet, don't get crazy, but I did make enough to pay for firing the kiln!