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When we originally built our kiln in 2000, we used all recycled brick and built it around the size of shelves we already had. It was a flat top, built mainly of stacked arch brick for the walls and a fiber (ceramic blanket) and heavy sheet metal roof. Not fancy, but we had a kiln and didn’t have to spend much money to put it all together.
It took at least 7 years of painstaking tweaking and firing before I really got to know its ways. About 5 years ago a dog we had knocked over the entire stack of old brick we were using for the kiln door, breaking most of them!! (..sigh) Long story short, it has been a struggle from the get-go to achieve reduction with any reliability, if at all.
As I think I mentioned in my last post, the old kiln as it was is no more. The flat roof – gone. The danger of fiber bits falling down into pots if you accidentally brushed the roof of the kiln with your head when stacking/loading – gone. The flat top was replaced with a retrofitted sprung arch and we finally were able to get new brick for the door. Extra fiber and roofing tin wraps the outer walls now as well.
The other exciting change made was replacing the old severely warped cordite shelves in favor of 6 new nitride bonded silicon carbide shelves. As you can see in the pictures, some of the old shelves were warped an inch and a half to two inches in places (I put one of the new nitride bonded shelves beside the stack of old shelves to show the difference in thickness and flatness). As with a wood or soda fire, loading typically involved painstakingly “wadding” each and every pot for the firing with a mix of 60/40 china clay to alumina hydrate. It was the only solution I could see to prevent warping. I have several potter friends who have those zoomy Advancer shelves that run about $100 a shelf in the size I was looking at. The nitride bonded are a step down from the Advancers, but are a lot less cost prohibitive, costing maybe $20 or so dollars more than a comparably sized cordite shelf.
These new nitride bonded shelves weigh all of 11 pounds (the old cordite shelves in comparison weighed 44 pounds!), so loading the kiln takes a lot less of a physical toll on me and I can load it independently. I still do wad some – little teeny wads – (vs using kiln wash or sprinkling alumina hydrate on the shelves), especially on those clay bodies I might be firing that might be a bit tighter than our native clay to prevent sticking, Loading takes a fraction of the time as does the preparation of the wadding itself. Now that I have flat shelves, the wads can be glued on in advance as well.
The new arch in combination with the new flat shelves gives me at least, I am guessing an extra foot of stacking space. Not only that but the kiln now reduces and fires more efficiently using about a third less propane per firing. With the rising price of propane ($264 for 75 gallons this last delivery), the upgrades to the kiln and shelves couldn’t have come at any better time. (Better for the environment as well.)
As an aside, we got our new shelves and brick from Larkin Refractory Solutions in Atlanta. Wonderful customer service and knowledgeable staff.
Further to my last post, and upon searching upon the newly updated Kiln Walk web site, they have four or five great and informative video clips about their 35 ft long anagama kiln and the firing last year that are bound to get your woodfiring juices flowing – the construction, bricking it up to fire, as well as other tidbits from Brian Harper and Don Reitz.
Brenda and Marty Stokes have worked very, very hard in the last 4 or so years at getting the Kilnwalk Society going (including donating a piece of their land for the project), and I can’t personally think of any better ambassadors for such an endeavour. This is one of the most exciting things that has happened to our part of the Gulf Coast potterywise and its open to everyone, not just academics.
(Remember their second anagama firing is coming up in just 3 weeks.)
The Gulf Coast Kiln Walk Society, out of Navarare, Florida, has some pretty cool and exciting things coming up this fall, including the second firing of their 32 foot anagama kiln which they built and fired for the first time last year.
Mr Masayoshi Shimizu from Iwade City, Japan, will be arriving November 27th to orchestrate the firing which will take place the first week of December.
Events relating to the firing include:
- Dec 2-4 – Glazing and loading of the kiln
- Dec 4 – The Ceremonial Lighting of the Anagama Kiln
- Dec 16 – 9:00 am Kiln opening
- Dec 16 – 9:00 am – 4:00 pm – 1st Annual Woodstoke Pottery Festival
While the deadline for members to submit a piece to the firing has passed, its a great opportunity to and see a master at work and find out what the excitement of an anagama firing is all about.
Mr Shimizu will also be holding a master class and slide presentation at the University of West Florida on Wednesday, Nov 29.
As per the Kilnwalk calendar, please note that all events are free and open to the public. Please click on the links above or call 850-939-2744 for more info.
Hope to see you there!
In the past few months, I’ve posted pictures of some of our pottery here on the blog and on our web site, now here is a little info about it.
All our raku vessels, are individually formed, carved, brush-glazed, and fired, using an American variation of the Japanese firing technique known as raku.
A glazed pot is heated to approximately 1825 degrees Fahrenheit. Its then taken from the kiln while its still red-hot, gently placed in a bed of pine shavings, and then covered (as you can see in this picture, we use a wheelbarrow or on other occasions in a metal wash tub as our pine shavings receptacle). When the oxygen in the air surrounding the pot is depleted by the flame, the flame then looks to the glaze for more oxygen molecules to consume. A chemical reaction may take place in the glaze, causing spontaneous and random flashes of color and metallic lustre. As the pot cools, a random crackling (or crazing) of the glaze occurs as the clay and the glaze expand and contract at different rates. What also happens is the carbon from the burning shavings fuses to all the unglazed surfaces and cracks in the glaze, turning them black. The piece, still hot, is then extracted from its bed of shavings and is quenched (or rapidly cooled) with water. Doing so not only cools the pot to the touch, but sets the colors before theglazes have a chance to reoxidize. Some of the results can be quite spectacular and its easy to understand the allure of pottery fired in this way. No two peices ever turn out completely the same and every one, in its own way, is one-of-a-kind.
The majority of stoneware clay we use for our functional pottery is from abundant native Alabama clay deposits, usually found within just an hour’s drive of the studio right here in Baldwin Country. The deposit Lowell working on here is right along a local roadside. The clay that seems to work best is whitish or, better yet, almost a bubble gum color. It fires the highest and has the least amount of impurities which is perfect for durable functional ware. Our functional pottery is individually formed, most of it on a potter’s wheel, is individually decorated, and then high-fired in a propane fueled gas kiln to approximately 2400 degrees Fahrenheit.
I’ll have to cover in future posts some of the primitive-fired pieces we do as well as the ongoing journey of the building of our small wood kiln using recycled materials…