Monday, September 26, 2011

Recent Firing

Fired goodies in the kiln
My kiln firing one week ago went well and yielded good results. I was pleased overall with the color and the variation in salt patterns and flame-flashing.
Table of ware from the kiln

Medium jar with faceting
There is always that amusement which comes out of the kiln. This time it was the fact that the pieces below one of the ports where I put the salt in were actually kind of dry-feeling. The faceting jar in the photo below was one such piece. Usually the pieces below the ports are coated in salt and rather shiny, this piece and another one were rather matte.
Another medium jar with faceting.

Good salting on the teapot
Overall, the kiln had an excellent salt coating on everything. I think closing the damper when I salt makes a huge difference in the coating on the pieces.
Twist handle pitcher

I love the orange peel which covered some of the pieces!
I am still playing with the blue slips. The ones which got a really good salting turned really vivid blue, which is beautiful! The pieces which were closer to the top and may not have gotten quite as much salt turned rather dark and near-black as the other trials have rendered.
Good blues

Excellent blue!

Somewhat black in color, but still blue!

The brown glaze I use for a liner came out of the kiln with a look I had never seen before! It has an illustrious gold flecking through the bottom, and is really quite spectacular!

If you follow Liberty Stoneware on Facebook, you may have seen my update last week when I said the kiln pack at the top of the kiln blew up. After unloading, I found there were no direct hits from the explosion, and it more or less looks like it just crumbled and fell off of the front of the shelf. I made the next firing's cone packs earlier and let them dry out more, so here's to hoping that it goes well!

The next kiln was loaded up yesterday and I finished firing it today. I should be unloading on Thursday just in time for the Fall Festival this coming weekend!

Saturday, September 24, 2011

Announcement- Event in October

Postcard Front
 I've just ordered postcards for this event, but wanted to share here as well! On October 27th at 7:00 p.m. in the Sara Smith Self Gallery at the Randolph County Arts Guild, I will be presenting on my initial research on historic American salt-glazed and alkaline-glazed kilns. I will share some comparative photographs of the various kiln sites I have seen thus far as well as talking more about my adventure on the site of the kiln excavation in South Carolina. I expect it to be fairly informal, so please come visit and talk about kilns and one of the major components of pottery manufacturing! The event is free and open to the public!
Back of Postcard

Friday, September 23, 2011

New(er) toy

New(er) roulette wheel
I had to add the (er) onto "new" because I actually got this back in June, but am only now getting around to having a chance to play with it! I have obtained a collection of roulette wheels cast from original eighteenth and nineteenth century patterned roulettes. I cannot describe the amount of excitement I have for these! My first one which has been mounted was cast from a Philadelphia, I believe nineteenth-century, tool. It has such an intricate pattern and so many possibilities! Here is a close-up of the roulette:

Close-up of patterned roulette wheel
I tried making small cups to test out this little toy, I dried a few in front of the fan before rolling the roulette, which worked decently well, but still had some tackiness and the wheel took some getting used to.
Two trials
I tried the mug below in making a small bulge in order to press the wheel onto, but that did not go over very well. I should have taken a photo of the rather messy result!
My best result was from ribbing the side of the piece with a metal rib, spraying the roulette with PAM cooking spray and then pressing my finger on the inside as I slowly rolled the wheel as the pottery wheel turned.
Close-up of pattern
I think these new toys may be an impetus for building a pottery lathe in the spring! I think that will make things easier, and much more exciting! I hope to get the other roulettes mounted soon in order to share the other patterns!

Sunday, September 18, 2011

Mad Potter of Liberty

George Ohr, the Mad Potter of Biloxi. Courtesy,
As a nod to the Mad Potter of Biloxi, George Ohr, I have been feeling a little mad myself throwing two or three kilns worth of pots in about two weeks! Medium-sized kiln, mind you, but for someone (me) who does not make pottery full-time, it's been a bear! I am getting ready for the Randolph County Arts Guild's Fall Festival, dropping pottery off to Bramble Ridge Orchard, and pots to sell at Bramble Ridge's Apple Butter Festival on October 8th. This should explain my negligence of this blog, and I apologize.
Here's a sneak peak of what I have been up to.
Here is about one week's worth of throwing all glazed up and ready to go:
Table full 'o' bisque ware!

Bisque ware awaiting transport. Check out the new slip color!
And here are those pots loaded into the kiln just today for firing tomorrow. I got everything on those tables into the kiln except for three of the bigger pieces!
First kiln all loaded up
Here are the newer pieces I have made over the last week which will be put into the bisque kilns this coming week:

Lots of twist-handle pitchers!

I am excited about the lidded pitchers. I think they will be perfect for lemonade or sweet tea!

Decorated mugs

New stemless wine cups

I have been trying to make more compost crocks and have decided to stick with these two designs:

Compost crocks!
I'm testing out a new cobalt slip, so my slip when it is just put on looks purple, and if you noticed in the pieces which have been bisqued, it is REALLY blue! I also have put some red slip onto a piece which will be fired in about a week and a half:

Cobalt slip (purple color) with red slip floral decoration
I should unload the first kiln by Friday, so I will let you know how the results turn out!

Friday, September 9, 2011

Salt Glazing

Top of German kiln during firing. Kannofenbrand Film.
I recently had an e-mail inquiring as to what the process of salt glazing is. This is such an excellent question! So, I thought I would make it into a blog post in order to share some photos and go into a little more detail. I think all too often potters assume that people know the processes they use to make their pottery, and our audiences do not always ask! For me, I love questions, but I will admit that I do not always get the chance, or take the chance, to explain the process. If you know what salt glazing is, then this is an opportunity for you to see some really great images a friend of mine (thanks, Angelika!) captured from a video I have of a kiln firing in Germany. The video is called Kannofenbrand and is one of my favorite nerdy videos. The video shows a kiln firing from 2004 of a restored circa 1840 kiln in Hohr-Grenzhausen, Germany. The kiln is 42 cubic meters in size. Just think about that for a few moments.

I visited this monstrosity in 2007 and when I first saw the building above I said, "where's the kiln" and my host said, "That's it!"

Photograph of the same kiln from around 1950. From Alt-Hohr-Grenzhausen by Heribert Fries
I often start by telling people that I do not generally put any glaze on the exterior of my pieces. "But how are they so shiny?" The glaze is created by the salt. The shiny factor is determined by the amount of silica (component of glass) in the clay as well as the amount of salt put into the kiln. Silica basically attracts more salt. When the kiln is firing potters can tell the temperature of the kiln by using what we call "cones." These cones are made with different kinds of clay which melt at varying temperatures. By setting these cones up in the kiln we watch the temperature rise in the kiln as they fall.

Cones at the beginning of the kiln firing, all standing. Kannofenbrand Film.

Two cones down, one going down, the temperature is rising! Note the glow in the kiln as well, that is the heat building in the kiln interior.  Kannofenbrand Film.
When the kiln reaches roughly 2,200- 2,300 degrees Fahrenheit it is ready for salting. Some potters wait for a higher temperature, some actually salt at a lower temperature (salt will actually flux or break down at earthenware temperatures).  The temperature in the kiln must be hot enough to basically evaporate the salt once it enters the kiln, the clay must be hot enough, and the silica in the clay is fluxed, in order to grab the salt once it enters the kiln. Salting is done in many different ways. With the kiln in Germany, the salt ports are on top of the kiln, meaning that the salt is dropped directly on top of the stack. The salt is loaded into metal cans which are attached at the end of a metal rod.

Loading the salt into the cans. Kannofenbrand Film.
 Then the salt is poured into the ports on top of the kiln.
Salting the kiln. Kannofenbrand Film.
Notice in the two above photographs that the people are wearing cloth to cover their mouths, and look closely at the second photograph with the large plume of gray/white gas coming from the kiln. That is the salt. The salt basically turns into a gas, technically hydrochloric acid, and fumes inside the kiln. When the air pressure and moisture in the air is just right, it can get so foggy-looking around a kiln being salted! Now, you are probably thinking, hydrochloric acid, eh? Yes, it may not be good for you in large doses, and it definitely clears your sinuses.
An American potter who attended the 2004 German kiln firing told me that when the kiln was being salted, people started coming out of their homes and collecting around the kiln. He asked what they were doing and was told that traditionally people came to the salting for health purposes, that they thought the salt was beneficial to their health! In Europe now, most salt kilns are required to have a scrubber on their chimney in order to clear the fumes before entering the atmosphere. Here in the States we do not have regulations on salt kilns as much, and for the comparatively few and small salt kilns that there are, the amount of gases released is minimal. Historically, in parts of Europe there were regulations requiring potters to be moved and kilns to be put in other regions because people complained about the smoke and cloudiness.

This is a photograph of a kiln while salting from the 1920s in Hohr-Grenzhausen. From Alt-Hohr-Grenzhausen by Heribert Fries
Either way, the gas/cloud of salt created adheres to the clay body of the pottery in the kiln, creating a glassy surface. Depending on how much contact with the salt the pottery has, and how much salt is put into the kiln will determine how glassy or dry the pottery feels. When the kiln is done the result of the salting is a texture referred to as "orange peeling." You can make it out pretty well on the rim of the mug below. It basically creates small beads of glass created by the salt and feels like the surface of an orange.

Mug made by Liberty Stoneware. Good orange peeling on rim.
Synopsis of salt glazing:
1. Bring kiln to temperature (2,200-2,300 Fahrenheit)
2. Insert salt into kiln (various methods)
3. Salt turns into gas which adheres to the clay body of the pottery, making a glaze.

The German kiln firing in 2004 turned out pretty well! They had a mishap in the center of the kiln, where the floor collapsed partially, but all in all the results were good.
Results of the kiln firing. Kannofenbrand Film.

Tuesday, September 6, 2011


I had a visitor on a bottle for half of the day
Where have you been, Brenda? Due to my lack of blog posts, I thought I would post some photos and snippets of what I have been up to. We loaded up the last bit of kiln brick.

Kiln brick: some assembly required!
For about the last week or so I have been madly throwing pottery in order to fill a kiln soon.

New crocks and planters


New lidded jars

New compost crocks
This past weekend I demonstrated making pottery at the Old Fashioned Farmer's Day in Silk Hope, North Carolina.

Photograph by Laurie Newlin

I was located at an 1850 cabin and demonstrated along with weavers and a spinner.

Cabin with my booth to the left

Sue Szary demonstrating spinning
I was really excited to see the demonstrations across from me of the rock crusher and thresher.
Rock crusher


Demonstrator in the steam-powered chair factory