Wood, Salt, Ash: I dream of future beads.

Hooked on wood fire, enchanted with salt
(Warning: a lot of clay, alchemy and fire. Very few beads...)

I just unloaded my first ever group wood fired/ salt glazed kiln yesterday. Its ALL I have been working towards for three weeks; which is a scant amount of time to prepare enough work. I loved the entire process and am already dreaming up pendant designs that could work best with these two unique kinds of firing. Let me take you back to Saturday last:

Glazed work on palettes as we prepare to load the noborigama

Seven students and one instructor. Unload your already glazed pieces, 20-30 per person. Make a million wadding balls and glue them to your pots feet/base. Load kiln, 2 large chambers.

Wadding. There are a few of my pieces bottom right. 

Wood fire chamber on the left.  Salt glaze chamber on the right. 

Brick up kiln. The kiln was started at 7:30 pm on Saturday. The overnight crew of two students stoked the kiln steadily UNTIL 4 am. We worked in shifts, continually maintaining and increasing the fire over a 22 hour period, reaching ^ 10/11. So tired but so exhilarated...

Why do ALL THIS, you ask?

There are as many variations as the day is long, but there is a sense of mystery. The chemistry is well documented as to HOW this all happens, but I felt a bit like an alchemist preparing to transmute lead to gold. The sense of mystery, the possibilities, the wonder...

Wood firing: "Burning wood not only produces heat of up to 1400°C (2,500 °F), it also produces fly ash and volatile salts. Wood ash settles on the pieces during the firing, and the complex interaction between flame, ash, and the minerals of the clay body forms a natural ash glaze. This glaze may show great variation in color, texture, and thickness, ranging from smooth and glossy to rough and sharp. The placement of pieces within the kiln distinctly affects the pottery's appearance, as pieces closer to the firebox may receive heavy coats of ash, or even be immersed in embers, while others deeper in the kiln may only be softly touched by ash effects. Other factors that depend on the location include temperature and oxidation/reduction. Besides location in the kiln, (as with other fuel-fired updraft kilns) the way pieces are placed near each other affects the flame path, and, thus, the appearance of pieces within localized zones of the kiln can vary as well. It is said that loading an anagama kiln is the most difficult part of the firing. The potter must imagine the flame path as it rushes through the kiln, and use this sense to paint the pieces with fire."

Wood fired pots: 1. Cynthia Bringle 2. Ted Ernst 3. Terry Inokuma 4. Jennifer Harnetty 

Salt glaze: "Salt glaze pottery is stoneware with a glaze of glossy, translucent and slightly orange-peel-like texture which was formed by throwing common salt into the kiln during the higher temperature part of the firing process. Sodium from the salt reacts with silica in the clay body to form a glassy coating of sodium silicate. The glaze may be colourless or may be coloured various shades of brown (from iron oxide), blue (from cobalt oxide), or purple (from manganese oxide).

Salt glazed pots:  1. Robert Compton 2. Phil Rodgers 3. Oak Hill Pottery  4. Mark Bassett

And yesterday - the unloading! 

First thing we saw as we unblocked the door... The torso was bare clay. Thats the magic of wood firing. 

Pieces from a diverse array of students, and instructors work. 

sampling of my smaller work. More details forthcoming at jdaviesreazor.com/blog

Sadly I only slipped one pendant and one cab into the kiln. (Small pieces like that can be annoying to load in a super large communal kiln, and as it was my first time firing with this group I was cautious.) David, our instructor, gave me three palm stones as well. These pieces were unglazed, bare stoneware clay placed in the salt chamber. I love the earthy speckled texture. On the back you can see the bare spot were the pieces was "wadded" (set up on a piece of wet clay to prevent it from fusing to the shelf.) I think the aura of color around the bare spot is beautiful. 

I am on fire, pun intended with ideas! There will most likely be another wood fire workshop in the fall, run by the Perkins Center for the Arts in Moorestown, NJ. I'll be ready. I envision pendants and cabs, some glazed, others glazed in the carved areas only. Some bare clay - "painted with fire" and I see a series with a secret message/word/symbol on the back there the wadding keeps it clear... a secret message worn on your skin. 

Thanks for reading - I know that was a lengthy post with out much correlation to artist made beads and components. But I was excited to share and I DO have dreams of future beads in my head. 

Resources: 
About wood firing ( in depth)
Anagama firing wiki 

Salt glaze wiki

Freeform Friday - ready, glaze, fire!

Ready, glaze, fire! 

A photo essay of sorts this week... regarding my process of glazing pendants for a ^10 reduction* firing. I love ceramic clay, "real" clay as it is so elemental. Made of earth and water, it is tempered air and fire. There are many clays on the market, to be sure... but there is a magic, an alchemy in true ceramic clay and the transformations it goes through during the firing....

I work in two clays - stoneware and earthenware. The earthenware is a lower temperature clay, low fire glazes, brighter colors... another days topic, I promise. But make no mistake - still a fired ceramic clay -  fired to 1850 deg F, mind you!

At the ceramics studio where I work/teach we use stoneware; and we fire  "High fire" to ^10  - a toasty  2381 degrees F (1305 C)! The studio has a palette of glazes that we mix in house. They are made in 5 gallon buckets and are the correct consistency for dipping functional ware. I have the glazes I use most often in containers for brushing; I like them to be a bit thicker.  For my pendants - I glaze the top, and then wipe off the surface, leaving glaze in the designs. I showed the process below on a figurative sculpture:

1. Containers of glaze, and coffee! 2. Glaze brushed into designs. 3. Sponged off, leaving glaze in designs only. 4. Goddess figures ready for stain.

1. Pendants, bisques and ready. 2. Top surface glazed. 3. Edges and backs cleaned with a sponge. 4. Backs stained, holes cleaned of glaze.

 Since this is a communal kiln, loaded by the instructors - it needs to be streamlined, no fiddley stuff. There's no way to hang or stilt my pendants, so they are free of glaze on the back surface. In a group ceramics studio - the kiln is filled and fired as needed - when there is enough work ready to go. During a session in our studio, this is usually once a week. To be clear - firing the kiln TAKES a week! Not the firing itself...
Monday - load the kiln - 3 people, with breaks in the cold - app. 3 hrs. 
Tuesday - Fire the kiln. Varies due to ambient temps - app. 8-9 hours. 
Wednesday - the kiln cools. all day. 
Thursday - unload the kiln.
(Friday - no class) 

Pendants arranged on a piece of shelf for ease of kiln loading. 

Pendants visible midway up stack of shelves, on right side.

Can you still see the pendants? The kiln is almost half loaded here...
I believe the firing chamber is 5' tall at the center.

There is an air of excitement and mystery for every kiln unloading. The reduction process* creates a unique atmosphere in the kiln and results can vary every time.  Glaze application varies - thicker, thinner. So it is always exciting to see this:

After the door is removed, unblock the opening... 

Looks good! 

That carved tree? Its on the side of my shrine... and the pendants are at the bottom right corner of this picture. 

Success! Kiln harvest of the week.

I have probably written on this topic before - but I confess... its very exciting to have things in the kiln! I haven't had anything in the high fire glaze kiln since... November last year? These are new designs for pendants and components, stamps I carved from linoleum during the Polar Vortex days of January. And Berks Bead Bazaar is right around the corner.... So thank you for sharing in this week's journey! 

Jenny

www.jdaviesreazor.com

* Reduction - Reduction (adjective) refers to a kiln atmosphere which does not have enough oxygen in it to completely consume the fuel as it burns. Due to this deficiency, the flame pulls oxygen molecules out of the clay bodies and glazes, changing their character. Reduction can be also be used to describe clay bodies and glazes that are especially developed for reducing atmospheres. Reduction (noun) refers to the state of being oxygen-starved. It can also be used to replace the full term, "reduction atmosphere".

For more information: 

( These are simple overviews, not in depth treatises... ) 

The firing process - bisque and glaze

Oxidation and reduction 

Feel the heat! Ceramic cone 10 reduction firing...

This was on my plate this week - literally. It is a plate full of porcelain charms and pendants stamped with new (to me) designs and textures. Do you recall the post a while back where I made molds from a plethora of organic items? Star Anise, coral, sea urchins... they are finally seeing the inside of the kiln! 

The process can be slow - create, dry, refine, fire, glaze, fire... depending on the creator this can be a week - or a few months! For me I work in 2 very different clay categories. I work in earthenware, a lower temperature clay for my sculptural "Mythic Nature" pendants. I use commercial low fire glazes as they afford me a colorful, reliable palette with which to paint. These pieces fire in my kiln at home, an electric kiln, whenever I feel the need. Easy peasy. ( Temperature range - ballpark 1900F)

I also work at a ceramics studio where we fire to cone 10 reduction. ( More on reduction in a sec, hang on...) There are stoneware clays in a variety of colors and porcelain. The firing is done in a large, hand built gas kiln out in the courtyard. Its a bit rough, but a work horse. But it might get fired once a week, and it is a group firing overseen by my colleague who teaches the adult class. She fits in what she can, theoretically including student work before instructors, and trying to get a few pieces in from each student. So there is the waiting game, and I am an instructor so... Sigh. It can take a while to get small fiddly little charms in the kiln. 

Big Bertha in reduction. Yes - flames are flitting out!

With Beadfest coming in a few months - its a rush to make hi fire things now! I hope to include a few in each firing this summer, but classes are smaller and the kiln fires maybe every other week. 

This week - my colleague was away. So I loaded the kiln, and  it fired  today. And we did make sure to get my half shelf of charms in.... I wanted to show you the process: 

My porcelain

From the last firing... 

The kiln on the far left. Panarama shot. Pots everywhere... we got 95% of this in the firing. 

Building shelf by shelf, the full kiln, bricking up the doorway.

It took the 2 of us two hours. While this style kiln allows great flexibility for placement of shelves, it has to be rebuilt and reconfigured every firing. It fires with propane to app. 2377 degrees, and can take approximately 8-10 hours. It will cool for a full day, and as the weekend is here - we wont unload until Monday. It is nervous anticipation, like taking an exam and awaiting Christmas morning - all in one!

The reduction firing - in layman's terms - means that during the firing cycle one purposefully reduces the oxygen intake via vents on the kiln. This causes a "reduction" atmosphere inside the kiln - oxygen is leached from the clay and the glazes - magic! Or to be technical: "A reducing atmosphere is also used in order to produce specific effects on ceramic wares being fired. A reduction atmosphere is produced in a fuel fired kiln by reducing the draft and depriving the kiln of oxygen. This reduced level of oxygen causes incomplete combustion of the fuel and raises the level of carbon inside the kiln. At high temperatures the carbon will bond with and remove the oxygen in the metal oxides used as colorants in the glazes. This loss of oxygen results in a change in the color of the glazes because it allows the metals in the glaze to be seen in an unoxidized form. A reduction atmosphere can also affect the color of the clay body. If iron is present in the clay body, as it is in most stoneware, then it will be affected by the reduction atmosphere as well."

So there.

Its art and alchemy. 

Its primal. 

Its hot. 

Its chemistry. 

It can be a surprise... 

And I have to wait until Monday... 

Have a good weekend!

Jenny 

www.jdaviesreazor.com

Firing Copper Clay

I pulled an old post from my blog to share with you today. For those of you unfamiliar with Copper Clay I thought you might enjoy seeing the process.

Copper firing, basically from start to finish.

 There can be variations in the firing schedule of pmc, this is the one I've been using on my Copper work and it's worked well for me.

Here are the pieces all molded and shaped and filed and ready for the kiln.

First phase of firing is open shelf, 15 minutes at about 650 degrees.

This is what they look like after open shelf firing. All the black stuff comes off during the second Phase.

Then they get packed in Carbon for the second phase, 1700 degrees for about 3 hours.

Here they are all layered in the carbon and loaded in to the kiln.

3 hours later...

I let the container cool off to under 500 degrees before I attempt to remove it. Then I let it sit until it's much cooler. Below it's still hot enough I need to use my heavy duty welding gloves to handle it.

There they are peeking out of the carbon when I pour it out of the container.

Used my gloves and a metal spoon to start to unearth the pieces. Everything cools off rather quickly from here and by the time I've found the large pieces I can usually start using my bare hand to find the smaller ones. There are usually one or 2 that don't want to be found, so when it's completely cool I sift them through the slotted spoon back in to the container and find the stragglers.

Then...

And then...

Some of them are just about perfect out of the kiln, just a little brushing and they are good to go. Some need to be tumbled for awhile and then I usually take a torch to them to give them lovely variations in color.

So there ya go, approximately 7 hours later I have some pretty Copper goodies, not counting the time it took to get them ready for the kiln. Copper and Bronze are not quick processes.

Then some of them get listed on Etsy!

I actually don't do the open shelf firing these days and go straight in to the carbon.

Seems to work well for me. It's still a very long firing process, from start to finish about 6-7 hours. I usually fire it up before I go to bed and it's cool enough to remove in the morning.

Kristi

KristiBowmanDesign.Etsy