Here is a small sampling of work from the last firing. I dont have a good photo set up here yet and am making due in the gallery so there are lots of shadows. Enjoy!

 

I was finally able to get a soda firing in after I got back from Texas from the holidays. I made a few changes to the bag wall before I loaded. In previous firings the heat was not being pulled through the kiln evenly so I loosened up the bag wall to help with this distribution. The previous two firings had been with other people and this was the first time I had the kiln all to myself. On the first firing we had green work in the kiln and fired until 2000° F solely with wood and then hooked up and turned on the burner system. The second firing I shared with Scott Parady who put green work in again so we had to go slow but only used gas. No kiln logs were kept for either of these firings unfortunately. This firing I fired cold with no preheat as I bisque all of my work and wasn’t firing anything of a large scale. I let the kiln warm with one burner on low for the first half hour and then slowly started adding wood. I continued adding wood consistently until around 1500° F and had turned on all three burners within the first hour and a half. Although I continued to add wood sporadically through out the day the wood seemed to be more of a hindrance than a help in gaining temperature. I added a little more soda than I had in the previous firing as well as a small amount of salt. The last firing was overly dry. I had cut the amount of soda from 3 lbs to 2 lbs in firings 1 & 2 but went back to 3 lbs sprayed in near the end of the firing as well as about a cup or so of salt which I spread on a log that I stoked. I am pleased with the amount of surface I got through out the kiln, although it was a little dry near the stoke door where I was spraying.

This firing was 5-6 hours shorter than the previous two firings, had no preheat, and was more even temperature  and atmosphere wise throughout the ware chamber. I would like to have used more wood to get more ash effect but I am happy with the outcome overall.

Here is the kiln log if you want to look at it:

sodafiring11216cobbmountainartecologyproject

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First Firing of the Cobb Mtn Art & Ecology Wood/Gas Soda Kiln Designed by HP Bloomer & Scott Parady

Back in October I designed a soda kiln for Cobb Mtn Art & Ecology Project with Scott Parady. We had a limited amount of space and needed to tie into the stack that already existed for the train kiln, as well as keep the kiln as versatile as possible. Initially Scott wanted to have the kiln exclusively gas fired, but we eventually decided to make it a hybrid that could do both gas and wood but did not need one exclusively over the other.  We have fired the kiln twice so far and are still making adjustments to the bag wall in order to create a more even distribution of heat from top to bottom. The design was initially to be a catenary arch, but as I got into drawing up the plans we realized that the space would be greatly limited by having a completely catenary arch. This is why the flue side of the arch is a barrel arch and the firebox side is a catenary. Choosing to do this was quite an adventure for me, especially since we were building completely with straight bricks and did not have any arch bricks.

I decided on a cross draft and down draft hybrid based on personal experiences I have had with both types of kilns. The cross draft style of kiln gives great directional effects but frequently is inefficient in fuel use and has cold spots. Having cold spots in a kiln means that there are points where the flame is not heating efficiently. To resolve this you either have to over-fire the rest of the work or sustain a peak temperature for longer in order to let the heat “soak” in these areas which can also be equivalent to over-firing the rest of the kiln. By dropping the flue below the ware chamber the flame is drawn down and through the wares, and so the flame heats the ware chamber more efficiently.   Since we have no natural gas lines in this area and have to run off of propane, which is more expensive, it seemed to make sense to have a more efficient type of kiln that gave the option of being woodfired or gas fired.

Overall this is proving to be a great little kiln that can be filled fairly quickly. Firings have also proven to be less expensive than I had initially thought they might be. My previous experiences with propane to cone 10 have cost $180-200 per firing. We started the first firing without the gas and fired up to bisque temperature solely with wood. This didn’t seem to use too much wood and took us about 16 hours to get to ~2075° at the top of the arch. We turned on the gas around midnight and took it up to 2400° in three hours.  The last firing I shared with Scott before our Studio Open House and Sale in November was only propane fueled and used only $148 in propane. I think that we can speed the firing up when firing only bisqued work. I am gradually opening up the bag wall so that the kiln fires more evenly top to bottom, and am waiting for the shelves that this kiln was designed for. It was designed to use the standard 12″ x 24″ silicon carbide shelf instead of the shelves that we are currently using.

Fun things we did with this kiln that were new to me:

  • King brick as grate system. Used 13.5″ King brick as the grate instead of steel bars. We did this because we already had the brick and did not want to have to buy steel bars which would more quickly erode when exposed to the soda in the kiln.
  • Complex arch. This was done to give more usable loading space for work.
  • No arch brick. The arch was also built, as mentioned above, with no arch brick. This means that all bricks are straight and not keyed. All adjustments to the curvature were done with mortar.
  • Doglegged flue. The flue is at a 45 degrees to the kiln and the stack. This was because we needed to move the kiln over so that it would not block a spy on the train kiln and to give us more space in the kiln area.
  • Burner Manifold. We included a manifold between the propane line and the burners. We did this to equalize pressure so all burners received a equal amount of fuel.
  • Excavated firebox. Because we were tying in to a preexisting kiln our flue level was already at a fixed position. This meant that we had to excavate the firebox to have it be at the appropriate height. That is why we have a bricked-in clean-out pit in front of the kiln. Normally potters get around this by having the kiln elevated on cinder blocks and building individual chimneys for each kiln but this requires a great number of bricks and space. Tying two kilns together can limit firings to one at a time but can save a lot of space an bricks.

If I were to build this kiln again:

  • If I were to build this design again with more time and resources I would include more primary airs for the coal bed and firebox.
  • I would take more time to build a more complex floor that further recessed a channel for the flue into the floor.
  • I would like to make the firebox a little wider with a deeper recess for the coal bed.
  • I would give more space for a shelf to slide in behind the kiln and close it off. This is not something I want to allocate a pristine new shelf to, and older shelves have a tendency have a curve or accumulation on them that need to be accommodated with a slightly wider slot.
  • I like catenary arches for larger kilns and even more so when the arch is perpendicular to the stack. If I were to build this kiln again I would go with a sprung arch or a barrel arch to accommodate more room for work, the firebox, and the stoke hole. Building these types of kilns requires more steel for a frame to brace the arch.

I never posted this when I left New Mexico in August and am now in Cobb California, a very small community in Northern California which is home to the Cobb Mountain Art & Ecology Project. I began a residency at the end of August and have been helping around the property and with various other projects. This semester I will begin to teach at Mendocino College in Ukiah as a replacement for Doug Browe while he is on vacation for the semester.

The goals of the Cobb Mountain Art & Ecology Project as set forth by Scott Parady, who owns the property, are to 1) encourage art making and experimentation in ceramic art, 2) teach stewardship of the land, 3) promote sustainable living , and 4) build community. We have had 6 long term resident artist since this summer and just said goodbye to Zach Wollert who has accepted a tech job in Iowa. The overarching structure is to have 3 long term (1 year or more) residents and 2-3 short term residents or guest artists who stay live and work at the 3,000 sq ft studio space. We currently have a woodfired train kiln, a wood/gas soda kiln, two Bailey updraft gas kilns and a electric Cress kiln for bisqueing and midrange firings.

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Prehistoric porridge? First pots for plant cooking found

  • Seeds found during the excavationsImage copyrightSAPIENZA, UNIVERSITY OF ROME
Image captionSeeds found during the excavations

Prehistoric people may have cooked wild grains and plants in pots as early as 10,000 years ago, according to new evidence.

Scientists say the food was “a kind of porridge”, acting as the staple diet when there was no meat from hunting.

The pottery fragments were found at two sites in the Libyan Sahara, which was then green and fertile.

The ability to prepare plants and grains in pots would have been a big advance at the time.

Dr Julie Dunne, of the University of Bristol, said: “This is the first direct evidence of plant processing globally, and, remarkably, shows that these early North African hunter-gatherers consumed many different types of plants, including grains/seeds, leafy plants and aquatic plants.”

Green Sahara

The Sahara was then a green savannah dotted with lakes and rivers.

It was populated by herds of large animals, including hippos and elephants.

The people living there would have gathered wild grains from grasses, leafy plants and aquatic plants.

“The invention of thermally resistant pottery, which allowed plants to be boiled for prolonged periods, considerably broadens the range of plants prehistoric people could eat, including previously unpalatable or even toxic plants,” Dr Dunne added.

The Libyan Sahara looks very different todayImage copyrightTHINKSTOCK
Image captionThe Libyan Sahara looks very different today

Stones used for grinding have also been found near the fragmented pottery, suggesting grains were pounded into flour.

“Or they may have just boiled the grains for prolonged periods and made a kind of porridge,” Dr Dunne said.

“Interestingly enough, that is one of the staples in Africa today – it may be that this has a very long history.”

Pots were invented twice in human history – in East Asia about 16,000 years ago, then in North Africa some 12,000 years ago.

The researchers studied more than 100 broken pieces of ceramic material from archaeological sites at Takarkori and Uan Afuda in the Libyan Sahara.

They found that the pots were used to process a wide variety of vegetation.

The researchers discovered this by analysing the carbon isotope ratios of oily residues preserved in the pottery.

A fragment of potteryImage copyrightSAPIENZA, UNIVERSITY OF ROME
Image captionA fragment of pottery

The pots predate plant domestication and agriculture in the area by at least 4,000 years.

“The finding of extensive plant wax and oil residues in early prehistoric pottery provides us with an entirely different picture of the way early pottery was used in the Sahara compared to other regions in the ancient world,” said co-researcher Prof Richard Evershed, also from the school of chemistry at the University of Bristol.

The pots were later used to process animal products including milk.

Plant diets

Early humans had been eating plants for as long as three million years.

Plants from Takarkori - grass (d), cassia (e), fruit (f), grass (g) and grain (e)Image copyrightARCHAEOLOGICAL MISSION IN THE SAHARA. SAPIENZA UNI
Image captionPlants from one of the sites: grass (d), cassia (e), fruit (f), grass and grain (g and e)

At first, ancient people would have dined on fruits and berries which are soft and easy to digest.

Later, woody parts of plants may have been charred on fires, perhaps in open pits, to make them more edible.

The invention of pottery made it possible to cook plants by boiling, making them much more palatable and less toxic.

This would have been hugely significant in human history.

Starchy foods are a good source of energy and nutrients.

Cooked plants and grains could also have been preserved for future use.

They would also have been soft enough to feed to babies, perhaps leading to earlier weaning of infants thus boosting the fertility of women.

The research is published in the journal, Nature Plants.

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I finally got a few pieces through a few electric firings and will share some images with on but I also wanted to say a little about a group show I just did with Neil Celani, Virgil Ortiz, Adam Field, Forrest Middleton, Ben Carter, Rachel Donner and Justin Crowe. The ClayScope show was organized to explore the physical communities that digital social networks provide. We had a great reception on Friday and will be opening up our online shop this Monday (8.1.16). You should be able to visit the shop through the clayscope website.

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ClayScope Particpants: (L-R) Justin Crowe, Rachel Donner, HP Bloomer, Virgil Ortiz, Neil Celani, Adam Field, Ben Carter, & Joe (Sorry Joe I dont know your last name) from Periscope.

I will be making a few brief Periscope appearances as I am packing up my house over the next two weeks and hitting the road August 12 to move to California. My Periscope handle is hpbloomer so please go download the app and follow me.

Here are some images of new work some of which will be available in the Clayscope store.

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Hi all,

A few of you may have already read on my Instagram or Facebook pages that I am moving to California this August. In order to minimize what I have to move I have listed quite a few new and old pieces on my etsy shop. I will keep my shop open until August 3rd so get what you can now. My shop will reopen once I get making again when I’m set up in my new studio at the Cobb Mountain Arts and Ecology Project

Please go shop my etsy page:

https://www.etsy.com/shop/bloomer4

This really is a very beautiful video. Thought I would share. That is all.

This post is not about pots or clay but I hope it will broaden the way you think about what our subject matter is or can be.

I thought this was a great artist talk by New York artist Rashaad Newsome on his work back in 2013. I find his study and interest in communication and interaction fascinating. There is a nice balance between  sound and movement as social signifies and markers. Hope you enjoy!