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!

Friday, February 25, 2011

Face Jug Play

My engineering side has been dominating of late and I have been throwing on the wheel. So to shake things up a bit. I decided to try my hand at some face jugs. This has been on my to-do list for about the last 5 years (don't want to rush things). The first one is in the kiln undergoing a very long preheat to dry it out.



While that is going on, I finished number two.





And another is under plastic waiting to be smoothed out tomorrow. Got to admit, I have been having fun.

For some pictures of the results of the last firing, you can see them on Facebook

Monday, February 07, 2011

Juiced!



The electric kiln is loaded and waiting on a few bowls to dry enough to fire. The kiln is a Cress E27 which has about 7 cubic feet of space. Therefore, it takes roughly about 3 loads of bisque firings to fill my gas kiln. Plus or minus a bowl or two.

I threw some "juicers" yesterday and they dried enough to trim today. I got the idea for these from Elizabeth Priddy. She is a North Carolina potter who lives and works in Beaufort on the coast. She had a "how to" on her web site a couple of years ago that I adapted. She has put this along with other "how to" projects on a DVD which she sells. She also has one on doing brush painting that looks interesting. Take a look.

The thing she didn't explain was how to trim them once they were thrown. The juicing cone makes working on them difficult. The first ones I did, I just carved off the extra clay with a fettling knife freehand. It worked, but I then thought up this system were I use a tin can, a coil of clay and my griffin grip.


The can is put in the griffin grip and the top edge is softened with the coil of clay.


There is a lot of extra clay around the bottom of the cone that needs to be removed. Below is the before.


And a couple of minutes later, here is the after.


The trim tool is one of Philip Poburka's Tungsten Carbide Cutters. I have had it about 3 years now and I still cut myself on it yesterday. Ouch! But it is a joy to use once you get used to it.

Sunday, February 06, 2011

Trying to listen

I know I am not very punctual about posting, but then again no one is waiting there with bated breath to hear what I have to say. It is my intention to do more... What is that quote about the road to hell?

The pictures of the pots from the last firing have been taken and are converted to "dng" awaiting my processing them. I just upgraded to Adobe CS5 so I am working through it slowly trying to catch up to the new software. Do I spend way too much time playing around with software? Aaah, yeah. Latest round has me lusting for a 64-bit box and operating system and the latest Cintiq tablet. Did I mention a Camcorder? Anyway, I will post some of the refined images soon.

I stumbled onto the following video. It was a couple of clicks away from one a friend pointed me to. That one was good, but this one really struck a note with me. It is by Evelyn Glennie. To quote "In this soaring demonstration, deaf percussionist Evelyn Glennie illustrates how listening to music involves much more than simply letting sound waves hit your eardrums." She talks about music and listening, but it applies so well to art and life. Listen.




And for a little comic relief, my cousin posted this on Facebook. A good chuckle for us who are exploring aging in real time.

Old Rock Star Songs from comedian Tim Hawkins. Classic Rock Songs updated for the singer’s age.

Wednesday, January 19, 2011

Hijacked

The pots that were going to be fired from the last post were hijacked over to Rob's wood kiln and fired there. I got hijacked to do some engineering work so the kiln - and the blog - has sat waiting. Yesterday, I finally fired the kiln.

This was the kiln's first cone 10 firing. I have been thinking about moving to the cone 6 to 7 range (lower temperature) to save fuel and wear and tear on the kiln. It has been a debate going on in my head for quite some time. On the plus side is the savings in time, money and being slightly more "green" (if potters can be considered at all green in their processes). On the minus side is the change in glazes, experimentation required, and adjustments to aesthetics that are needed to shift from what I have been doing at cone 10. I think in the end I will make the shift, but in true Jody fashion, I will ponder it for a while longer.

However, I did want to prove that the kiln could fire to cone 10. That was the design temperature I set. The guy who sold me the burners for the kiln, advised that the kiln might not be able to make it to temperature and suggested bigger burners. I redid my numbers, checked them twice and stuck with the smaller burners (which are pretty damn big to begin with). But... I used to stand on the deck of the launch barge offshore, ready to push the structure off the barge into the water after 9 months of engineering and wonder, will it realy float like I calculated it would? They always did, but until it was out there bobbing in the sea, I kept running through the numbers in my head. So, at least once, I had to go to the design temperature of cone 10.

It made it no problem. In fact, I had to hold the burners back.

Kiln opening will be Friday. My youngest daughter is coming for a visit on her way back to Texas so I will wait until she is here.