March 04, 2006

Firing an old idea anew

It was half past four when I walked into Ajay’s backyard with my father. His house is painted deep red the colour of red oxide not uncommon in Goa. Though there are no yellows along its edges to go with the red, something you’d expect to see in Goan houses, the house spat enough red at the sky to stand out even if much of its bulk hid behind itself on the turn in Bethoda, past Sapna Ceramics, up a narrow road that runs past a series of duplex flats.

There is this patch in his backyard where Ajay has spent a significant part of his adult life since 2003. Few places around have been dug up more than that patch, measuring over 20 sq. ft. or thereabouts. And today as my father and I walked past his porch fronted by flowering trees, turning left to take the narrow path between his house and the garage that is home to a succession of his two-wheelers over the years, dodging a coconut tree and sundry other things that lie scattered all around the place where his father has planted guavas, breadfruit, black pepper, drumstick, and mangos among other varieties, I was taken aback to see Ajay peering out from behind what looked like a brick chimney rising over the curving roof of a rectangular structure in the front, and a largish opening that ran along the length of the structure. Another kiln I thought; the fifth in three years. Looking at the brick structure rising up, I reckoned from the look of it that this one would last longer than its predecessors that Ajay buried in the same pit where he had laid their foundations once. From electronics, rock music, painting, reading, to clay-work, Ajay Dongre, a brahmin originally from Malvan in the Konkan region of Maharashtra to the west of India, had made one long journey in more ways than one from his college days when he went around town on his red Kinetic Honda scooter with a 'Thank God I'm an Atheist' sticker displayed prominently on the front of his scooter. I tease him about the sticker once in a while, not that he has suddenly found common cause with god. He is still an Atheist. In some ways he hasn’t changed much, only in some ways though.

I first met Ajay in the mid-eighties when I was in school. In the early years, soon after his arrival in Goa from Bombay after his father was transferred on his job with the Food Corporation of India, Ajay became a part of our group, playing cricket with us after school hours, and joining us on our cycling trips to the Bondla Wildlife Sanctuary in school vacations. Those trips to Bondla, 24 kilometres each way, left memories that’ve lasted time even as it swept away many others. At other times we shared an interest in electronics, building gadgets and generally having a good time when we were not studying, which was often. Eventually we completed our post graduate degrees; he took Physics while I opted for Computer Science. On completing his degree he took up teaching, and I left for Bombay in search of a job.

Meanwhile we explored Goa together, free-riding and photographing along the way. By then Ajay had taken up a job teaching Physics and Electronics at a local college, a job he still holds except for the year-long break he took to teach at Lisa Chowgule’s school in Vasco last year. After spending several years with what came to be known as the Abhiruchi group, named after the youth who congregated at Hotel Abhiruchi in Ponda, whiling away evenings over endless cups of tea and cigarettes and thinking up things to do but not quite managing to except occasionally getting together to organize a bicycle motor cross, Ajay sensed that his spare time after work was going nowhere over the endless cups of tea and banter. He 'opted' out of the Abhiruchi group to use his after-job hours to pursue painting instead. It was then he drifted toward sculpture after trying his hand at painting, eventually finding company in Raju Gujar and Donald D’Souza. Raju runs a metal fabrication unit in Jaycee nagar and has a yen for sculpture, having fashioned from chalk pieces a series of rivetting figurines that never fail to draw attention whenever exhibited. Ajay’s aptitude for design and Raju’s ability to implement the design at his workshop worked well for them both, resulting in sculptures made from scrap metal. All along Ajay practiced claywork, experimenting with clay, form, and kiln firing though the availability of refractory bricks to construct the kiln was as much a problem as was the Kiln design until he got hold of Frederick Olsen’s The Kiln Book from a fellow potter, Gauri Divan, a studio potter practicing in Goa.

Ajay sourced refractory bricks for his new kiln from a local foundry. "They had large quantities of these reject-bricks they were prepared to spare, rejected on account of fine cracks they developed and which could leak molten iron if used in their foundry. I recycled them for use in building my kiln," he told me. These bricks were originally designed and manufactured for use in making iron ignots. They’re hollow from the inside to allow molten iron to flow in a complex circuit. He picked up two varieties of these bricks. One measured 15 inches in length and 3.5 inches in width and height. The other variety measured 9 inches in length; the width and height were the same as the other.

Since these bricks were not designed for construction purposes they presented quite a few problems to Ajay and Raju in the construction on the kiln. Ajay cut them to required proportion to get them to fit in. The hollow insides presented a different set of problems. He filled mortar (made of chalk powder, sand, clay, and sieved mud) in the hollows that ran the length of the bricks, and placed them at right angles to each other to prevent any heat loss through 'straight lines' along the hollows. "It was quite an experience setting these bricks according to the kiln design," Ajay let on when we sat talking in his first-floor room where he has his studio; the remaining rooms are stacked with his clay work and sculpting-implements. Over 1000 of these refractory bricks went into the making of the new kiln; 600 bricks of the longer variety, and the remaining of the shorter one. "If we had managed to get refractory bricks specially designed for construction purposes, our task would’ve simplified greatly," he said. ”We needn’t have bothered cutting the bricks to desired lengths to get them to fit in then.” However they had to fetch special bricks from Khanapur in Belgaum, a border district in the neighbouring state of Karnataka, for use in constructing the kiln’s chamber floor measuring 40.5 inches x 40.5 inches inclusive of the two openings that let in flames into the chamber from the fireplace underneath. For now he is thinking of using wood to fire the kiln. "Gas-firing is a costly proposition as of now," he said. Both flame inlets, constructed diagonally across from each other, measure 18 inches x 6 inches each. "The kiln at Khanapur is a massive one. So big that trucks can drive in. It’s truly huge," he said of their trip to Khanapur. He’s expecting his new kiln to generate a temperature of 1200 degrees centigrade. "That should be useful," he says, smiling at the thought.

Refractory bricks or firebricks as they’re known are made to withstand higher temperatures. Clay is the common refractory material available in nature. However, clay quality varies from place to place. Ajay sources his clay from Bicholim as do most people who practice clay-work in Goa. Typically clay consists of Al2O3 (Alumina) and SiO2 (Silica). Its Iron Oxide content is a variable. The Alumina content is varied to control the clay’s refractory quality, increasing it enhances its refractory quality.

Ajay shows me Frederick L. Olsen’s The Kiln Book. He used Olsen’s book to design his kiln. It lists several basic principles to follow in constructing a kiln. The principles Ajay followed were specific to the type of kiln he is constructing – Fast-Fire Downdraft kiln. "It was a challenge to conform to Olsen’s guidelines with bricks that were originally meant for use in an Iron Foundry," he said. "However we did try to approximate closely to Olsen’s guidelines." In his The Kiln Book Frederick L. Olsen has crystallised his lifetime work experience and offered tried and tested kiln designs for use by professionals and amateurs alike. For over thirty years, Olsen’s The Kiln Book has explained in clear and detailed instructions and text the process of kiln design, choice of design, method of firing, fuels and combustion techniques, materials and construction. Ajay used the following principles from Olsen’s book in constructing his kiln.

The cube is the best shape for the kiln.
The chamber housing clay-work should allow for a free flow of flame.
The fire-place in wood-fired kilns should be ten times the chimney cross-section, and the inlet for the flame should be the same size as the outlet that opens into the chimney.
The taper of the chimney as it rises up should create a natural draft, and aid in trapping heat.
The chimney height should equal three times the height of the chamber multiplied by one-third the chamber length plus the height of the fireplace.
Critical areas of a kiln should be planned and built to be altered easily.

"Though a height of 18 inches was sufficient, I designed the fire-place to measure 21 inches. I thought it better to allow for tolerance on the higher side than fall short eventually. If the efficiency were to drop, I can always bring down its height by raising the base," Ajay said as Raju, whom Ajay calls 'My Chief Engineer on this project', nodded solemnly. "Even an inch of gap makes a big difference. I’ll know by how much once I start using the kiln." Similarly, he left the top two layers of the chimney loose to allow for any future modifications depending on kiln performance.

In his experience building four kilns of various dispositions before this one, Ajay lists several factors affecting the Firing performance: humidity, wind direction, the type of wood used to fire the kiln, the size and shape of clay sculptures packed into the Firing chamber and the way they’re packed together, and so also their thickness.

He shows me small clay sculptures (usually faces) that he makes from time to time, and which are favoured by some of his more fashionable students for use as key-chains. A few wear them around their neck. "They asked me for more of these," Ajay told me when he first made them over a year ago, surprised at their popularity. "These pieces were fired using sawdust," he tells me. "Sawdust firing is the simplest form of firing clay-work. It is particularly good for simple kind of work. Group the pieces together, pack them in sawdust and light the whole thing." He used the Bottle kiln to good effect when he first started out with clay-firing in 2003, two years after starting out with clay-work. Until then he never clay-fired his creations. Whenever I went over to his place he I would look around his room, stacked with books, cassettes and audio CDs, for new sculptures. "Many pieces I did in those days cracked from not firing them. I did not have my own kiln then," he reflected. Eventually he built his first kiln in 2003 - a Bottle kiln.

The Bottle Kiln gets its name from its shape. It is the oldest and the simplest kiln known to man, and is a modification of Bonfire-firing that people practiced in ancient times where clay-work was stacked together and covered with firewood before lighting it. Though it resulted in loss of clay-work, sometimes in significant quantities due to lack of proper temperature distribution, it was used for a long time for want of a better design. The Bottle Kiln improved upon the Bonfire technique but was not found to be effective for all kinds of clay-work, leading to the invention of better kiln designs.

"I might’ve still been stuck with my previous kiln (a Bottle kiln) if it was not for the over 100 pieces of table-decorators that a friend ordered for that were blackened beyond use when I fired them recently," he said, showing me some of the severely blackened pieces while we (Raju, Donald, Ajay, and I) took a break from digging one feet deep pits around the kiln to put up a scaffolding in place for use in raising the chimney to its slated height of 14 feet the next day. Raju, in purple coloured bermudas, and Donald sat eating mirchi bujjiyas that Ajay had ordered from a Rajasthani outlet in the colony. We took our plates and gathered around the tap in the backyard where the maid washes utensils and sundry birds saunter over for a quick bath or drink from the dripping tap in summers. It was the first time I'd eaten a mirchi bujjiya that had potato-filling in it, the kind you might expect to find in a samosa but not in a mirchi bujjiya. "I had to discard the whole lot," he said turning the blackened clay pieces over in his hand. "Lack of proper oxygen resulted in the reduction of iron content in the clay, turning it black."

I’m not sure how long he can sustain his new kiln with firewood. Not only is it costly and inefficient when compared with a gas-fired kiln, it is quite a hassle to source firewood over a length of time. "The kiln design need not be modified much to accommodate gas-firing," he explains. "If not for the cost involved I would’ve gone for right now. Eventually I will have to use gas-firing."

He derives particular pleasure from the fact that the kiln now nearing completion did not cut deeply into his finances. "I paid 5 rupees each for the refractory bricks, 500 rupees for transporting them from the foundry to my place, 8 rupees for each butti of sand in preparing mortar, 500 rupees for whiting (chalk powder) for use in preparing mortar, 1,400 for 4 cubic meter of raw clay, the contents of a TATA 407 truck we hired for transporting the clay from Bicholim to my place, and 600 rupees labour charge for the three days it took to sieve the raw clay. About 8000 rupees in all."

As I prepare to leave, I congratulate him over his effort. "Wait until I test-fire the kiln," he says, smiling, betraying his concern from his experience with his previous kilns though they were nowhere near the sophistication that went into constructing this one. Outside, the night is still except for an occasional vehicle passing by his house up the incline, noise trailing in its wake. Suddenly it’s like old times even though times have changed and we cannot sit for long periods the way we used to, reviewing and listening to music, discussing dreams and ideas, cribbing about our education system, thinking up mechanical models one could build, going through picture books, and talking books and of even older times. But still . . . .

1 comment:

Sanchez said...

Oh my my !!!! This is so nostalgic. If I was in Goa, I bet I would have been working with Ajay, helping him build his
kiln and eating mirchi bhajji with Don. Say Hi to all of them when you meet them next.