Showing posts with label firing process. Show all posts
Showing posts with label firing process. Show all posts

Friday, February 21, 2014

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