10: Sustainable Ceramics with Nancy Selvage, David Binns and Guido Strijbos

Introduction to NSEKA 360

0:00Welcome to NSEKA 360, a podcast that provides you the ceramic content you crave during the 360 days that surround our annual conference. We are excited to engage our listeners through social media and encourage you to follow us on Facebook, Twitter, and Instagram. For up-to-date

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Panel Introduction

0:39This is Ben Carter and I'll be your host. For this episode of NSEKA 360, we have a panel on sustainable ceramics with Nancy Selvage, David Benz, and Gerard Blau. The presenters share their experience with evaluating and improving the environmental impact of their ceramic practice. More information about sustainability can be found by searching Green Task Force at blog.nseka.net. To get involved with the task force, look for topical discussions at this

1:09year's conference in Pittsburgh. Previous topics include ceramics and climate change, reducing your carbon footprint, and firing kilns with repurposed vegetable oil. To register for next year's conference, please visit nseka.net.

Nancy Selvage Introduction

1:31My name is Steve Hilton. I'm the program's director for NSEKA, and I'm here today to introduce Nancy Selvage. Nancy earned a BA degree in art history from Wellesley College, an MFA in sculpture from the Museum of Fine Art, Tufts University. And she's been recognized with numerous awards for her artwork, most notably a Massachusetts Art Artist Foundation Fellowship and two Massachusetts Art Council New Works Commissions. Nancy's educational career includes

2:02a long tenure as the director of the ceramics program at Harvard University. And last March, she did a keynote lecture at the conference Ceramics Arts and Design for Sustainable Society in Gothenburg, Sweden. Please welcome Nancy Selvage.

Sustainability in Ceramics

2:17Thank you for joining David Binns, Huito Stribas, and me to consider how we all can contribute to global sustainability through our work in ceramics. We greatly appreciate this opportunity to share ideas with you. The interaction of culture and nature is a critical focus for contemporary artists and designers. Creating work to address this relationship becomes very problematic when the

2:53art-making practice itself contributes to an unsustainable balance between cultural expression and natural resources. Efforts to establish a sustainable balance are generating new technologies, production methods, expressive strategies, and aesthetic values. Knowing how to evaluate, discuss, and improve the environmental impact of one's ceramics practice is a critical art-craft survival skill.

3:26Artists and educators need to address carbon footprint issues with galleries, clients, and students who are concerned with being green. We need to comply with state and federal environmental regulations and contribute to university energy goals. We need to critically evaluate energy-saving claims by equipment suppliers, even those by our fellow panelists. We might need to provide detailed energy

4:03information to juries evaluating our proposal for LEED-certified projects. We might need to justify the sustainability of our work in order to be featured at the Smithsonian Craft Show. And we need to determine the most effective approach to reducing our unique environmental impact within our unique locale. This locale is the USA overheating from overconsumption of fuel obtained through military intervention. What is the definition of

4:42sustainable ceramics of sustainable ceramics practice? Fundamentally, it is one that keeps atmospheric carbon dioxide below dangerous levels, conserves natural resources, and does not pollute the environment. In this panel, I will discuss resource conservation, carbon dioxide emissions, and fuel options. David Binns will address strategies for the

5:15creative use of clay and glaze waste materials. And Harad Blau's colleague, Huito Stribas, will discuss energy-efficient kilns and firings. And at the end, we will focus on your ideas and questions.

Natural Resource Conservation

5:31Let's consider natural resource conservation first. Since clay is continually replenished by the geological weathering of feldspar, which comprises 60% of the Earth's crust, we do not have to worry about depleting this renewable resource. However, mining and processing of all materials used in ceramics can have negative impacts. This is an abundant deposit of clay on Martha's Vineyard in Massachusetts. But it is off limits to all but Gladys Wittes, a Native American whose tribal people own this land.

6:18She preserves the color of this clay by not firing her vessels and canoe forms. The extraction of minerals is responsible for about 7% of total global energy consumption. To reduce the energy impact of securing our minerals, we should pay attention to local geology and make friends with excavators. The webs find their stoneware clay along the side of a road within an hour's drive of their Alabama studio.

6:54In contrast to the abundance of clay, supplies are limited for most of the minerals used for color in glazes, stains, and underglazes. Copper, chrome, cadmium, lead, and tin are essential minerals for creating reds, pinks, yellows, oranges, greens, and blues. The usable global reserve of these minerals will be depleted within 20 to 30 years at current global demand levels and sooner with accelerating increase in demand.

7:31With improved technology or enhanced economic impetus for mining the less usable reserve, these minerals could last for 40 to 60 years, not counting an increase in demand. Iron and cobalt are also essential for colors. Cobalt for blue, iron for black, brown, tan, yellow, and celadon green. Their usable reserves will only last for a few generations. These minerals are unsustainable resources and the mining and irresponsible disposal of them pollute land, air, and water resources.

8:08A sustainable ceramics practice would eliminate the use of these minerals or purchase them from recycling or environmental cleanup operations. If they are used, 100% recovery and reuse from glazing operations is essential. This company sells reclaimed iron oxide and manganese dioxide from an environmental cleanup process that uses no energy input, just gravity, oxygen, and time. In my own studio, I rinse brushes and other glazing tools in sets of containers designated for different colors of underglazes, stains, and oxide washes.

8:47Depending on your own palettes or recipes and materials, you can design a similar system to save and reuse these valuable ceramic materials. Know what you are using. Know what you are using. Get recipes or MSDS sheets of all of your glazes, clays, stains, and underglazes. If you do not use barium carbonate as a sulfur binder in an earthenware clay body, or barium carbonate, sodium borates, or lead compounds as fluxes and glazes,

9:17or any colorants, except perhaps for small amounts of iron, you do not have to worry about contaminating the environment. If, however, you use any of the other colorants or fluxes on this list, you do have to be responsible to make sure that they are used, reused, and disposed of in a responsible way. At the ceramics program, I was responsible to work with representatives of the university and from the Massachusetts Water Resources Authority to ensure our studio operations were not contaminating the wastewater.

9:58After passing many MWRA test samples with our double rinse system, one wastewater sample indicated a borderline level of copper. In consultation with the university administrators in health and environmental safety, we initiated a system of triple rinses and a settling tank that prevented any of our waste from glazing from going down the sink.

10:28On a weekly waste basis, the rinse containers were rotated out of use so that the glazed residue had time to settle undisturbed. The clear water was siphoned off, the top, and the sludge was collected in a barrel for pickup by an environmental waste management company that disposed of it in a manner that prevented leaking into the environment. Ideally, this sludge would have been used as an ingredient in scrap glazes or in some new product that was worthy of firing such as the exciting work by David Binns that you will see very soon.

11:01Or the sludge would have been saved, since it will gain value as the global demand increases for the limited supply of its ingredients. In the future, potters could be paid for their glazed sludge.

Carbon Footprint

11:14Now to the most difficult sustainable challenge. Propelled by research on accelerating environmental impacts, leading atmospheric scientists consider 350 parts per million to be the highest safe level of atmospheric carbon dioxide for preserving the environment to which life on Earth has adapted. We are currently rapidly warming at 392 parts per million.

11:46Some scientists hope that reducing to 350 parts per million by mid-century is possible. Others are more pessimistic. Saul Griffith has calculated the magnitude of this challenge for the world and for his personal lifestyle. Currently, 90% of the world's energy is generated from burning fossil fuel. To reach the goal of 350 parts per million, fossil fuel burning would have to be cut to zero within 25 years.

12:19To level off at the dangerous amount of 450 parts per million of carbon dioxide, fossil fuel would have to be cut from 90% to 20% within 25 years or it's too late to avoid catastrophic change. Since there is an extremely limited global infrastructure for replacing fossil fuels with renewable energy. An aggressive mix of conservation, carbon offsets and renewable energy development is critical immediately.

12:52If our studio practices are not on track to be powered by 100% renewable energy within 25 years, we cannot claim them to be sustainable. Before I began to research data on the energy impact of ceramics production, I assumed that the energy investment of ceramics would be comparable to the energy required to process other materials. And I assumed that the durability and longevity of fired clay would easily compensate for its energy investment.

13:27I firmly believe that using a ceramic mug was much more environmentally friendly than using a disposable paper, plastic or foam cup. However, this belief has been shaken by reading two shocking studies from the early 90's. As you can see from this chart, paper, foam and plastic are more energy intensive per unit of weight to produce than ceramics. However, since ceramic cups weigh more than plastic, paper or foam, the ceramics cup has more embodied energy.

14:01This is an indication of the wide range of energy values for producing ceramics used in the two studies. The good news is that some factories were able to be much more energy efficient than the average. The bad news is how much more energy was required by the studio potter's smaller operation, even though he had a soft brick kiln large enough to fire 400 cups at a time. Given the average energy used to produce an industrial mug and wash it in an efficient Canadian dishwasher,

14:32the mug breaks even with a paper cup after 39 uses and washes, but doesn't break even with a styrofoam cup until after 1,000 uses and washes. And because the United States has less hydroelectric power than Canada, the styrofoam cup never breaks even in an American dishwasher. The Dutch study compared porcelain to paper and hard plastic cups and calculated the environmental and energy impact of mining, fabrication, and use

15:02on water quality, air quality, and landfill volume. The bad news is that reusing an industrial ceramic mug may never break even with using and throwing out a paper or hard plastic cup if water impact is considered. The good news is that improving the environmental impacts are possible and have been in process since this 1992 study. Even though this study focused on industrial products,

15:32it was very useful for showing the different things that we have to take into consideration when we evaluate our practice. And these studies indicate how critical it is to process ceramics with sustainable energy sources. More energy consumption than styrofoam does not mean less green if that energy comes from sustainable power sources. Since firing uses 60 to 80% of ceramics production energy,

Sustainable Energy Options

16:04let us consider sustainable energy fuel options for powering our kilns. A solar kiln built more than 200 years ago enabled Europe to discover the material science of Chinese porcelain. However, using solar energy directly without converting it to electricity is not currently a viable option for firing more than a small pot at a time. If you cannot afford to generate your own green power,

16:36the easiest and perhaps cheapest way to decrease the environmental impact of your ceramics practice is to purchase electricity from a company that provides and or invests in electricity generated by wind, solar, or water. My husband and I pay NSTAR in Massachusetts a green surcharge so that all the electricity in our home and home studio is wind generated. We pay an annual green surcharge of $230 for the 3600 kilowatt hours used by 24 electric kiln firings to cone 04.

17:14This sustainable option is much cheaper than installing our own green power system, but is only an option until the limited supply of green power is sold. To put these 24 low-fire kiln firings in perspective, they consume 10% of the total energy used by our New England home and home studio, which is heated by a combination of wood, natural gas, sun, and green electricity. Natural gas is a relatively clean fuel, but an unsustainable option.

17:49Natural gas produces more concentrated energy and less greenhouse gas emissions than any other fossil fuel and most biofuels. Burning natural gas produces 29% less carbon dioxide emissions than fuel oil, 43% less than coal, and 45% less than burning wood. And it produces dramatically less emissions of particulates, nitrogen, and sulfur oxides.

18:19In the last 10 years, natural gas extracted from shale by hydraulic fracturing has increased from 2 to 30% of the U.S. supply. This technology has been responsible for the contamination of aquifers and the uncontrolled release of natural gas, a highly potent greenhouse gas. Understanding that natural gas is a necessary interim option during the transition from fossil to renewable fuels, the Environmental Defense Fund is working with the Energy Department

18:49and state governments and gas companies to reduce these adverse effects. Firing captured natural gas, otherwise known as methane, from the decay of organic matter in shallow settlements and landfill is the firing option with the most beneficial environmental impact, since allowing methane to escape into the atmosphere is worse than burning it. Methane is 20 times more effective than carbon dioxide at trapping atmospheric heat.

19:21Unfortunately, capturing methane from a landfill is challenging and expensive. But Huido has a great solution, so stay tuned. In the energy exchange, methane gas from decomposing landfill powers a hot glass shop, a pottery kiln, and supplies heat for studios, greenhouse gases, an education center, and an art studio. Installing this system costs over a million dollars,

19:51and is projected to save a million dollars in energy costs over its 20-year life cycle. The most commonly used biofuel for ceramics is wood.

Biofuels for Ceramics

20:02This chart shows the design of a smokeless wood firing kiln that I commissioned for the Harvard Ceramics Program. It was designed and built by Kusakabe Masakazu, whose pioneering kiln and firing research has developed a kiln that has a larger firebox and a taller chimney than usual. This type of design induces a stronger draft, which allows for more efficient combustion with no smoke. However, even the most efficient smokeless wood kiln firing

20:33produces more carbon dioxide and greenhouse gases per unit of energy than natural gas, oil, or coal. Most potters consider firing with wood to be a sustainable carbon neutral practice because trees absorb carbon dioxide as they grow wood, and because dead wood will gradually decay and release almost as much carbon dioxide as a firing wood. The carbon dioxide emissions can be offset, but not until and only if replacement wood is grown.

21:07Chris Gustin uses an average of nine cords of wood for each of his six- to seven-day firings in this large onagama kiln that has 425 feet of cubic stacking space. One cord of wood is scrap from a furniture supply person, and the rest he purchases. So in one year, he uses 27 cords of wood for three firings.

21:40And in one year, one acre of New England forest can grow three-quarters of a cord of the 50-50 oak pine mix that he uses. Therefore, Chris's kiln needs 36 acres of forest solely devoted to supplying its fuel or solely devoted to sequestering its carbon emissions in order to have a sustainable carbon neutral firing.

22:07Unfortunately, our planet needs to be carbon negative instead of carbon neutral at the moment in order to get our atmospheric carbon load below dangerous levels. Using wood as a fuel has the long-range potential of being carbon neutral as long as global forest growth exceeds global demand. But currently, forests are already hard at work, absorbing one-third of the world's carbon dioxide emissions from fossil fuel burning. And wood is now the main energy source for heating and cooking for half of the world's population.

22:41And compared to a citizen from that half, the average American uses 15 times more wood for other purposes, building, paper, packaging, etc. Global supply and demand for wood is in a precarious balance, and demand will grow as fossil fuels are depleted or phased out. As early as the Song Dynasty, 800 years ago, there was serious deforestation in China. 400 years ago, in Jingdezhen, the center of Chinese porcelain production,

23:12fuel wood had to be gathered from more than 100 miles away. For creating sculpture, unfired ceramics is, of course, a very energy-efficient option. This 200-year-old unfired clay sculpture at the Peabody Essex Museum in Salem survived transportation from China in a sailing ship and centuries of New England's changing atmospheric moisture. And there's a 100-year-old Kokoschka sculpture unfired on the right

23:42at the Museum of Fine Arts in Boston. This large unfired clay sculpture by Roxanne Swenzel was recently installed at the Denver Museum. Currently, unfired ceramics is not great for functional wear. But perhaps we can learn to grow our ceramics at room temperature instead of firing them. Marco Polo was so impressed with how similar porcelain was to the lustrous, hard surface of a shell that he named porcelain with the name of the shell Porcelana.

24:13Recently, scientists have discovered how to make a very strong and lightweight ceramic material by studying the structure and composition of seashells. Unfortunately, I do not have time today to consider work by the many artists and designers who are addressing issues of sustainability with functional, conceptual, and symbolic work, including my own work in perforated metal and in ceramics. This piece was part of an installation with the moral imperative title,

24:49Mend Thy Ways, Mend Thy Wears. Reuse is one of the most important R's in the anthem, reduce, reuse, and recycle. And in this case, my using shards requires no firing. This series of vessels pays homage to the enormous global impact of Chinese porcelain and the cross-cultural influence of this trade. To end this talk, I would like to share a definition of art that I find very compelling.

25:20In Homo Aestheticus, Where Art Comes From and Why, Author Ellen Desinyake describes art making as an essential behavior that evolved to enable cooperating individuals and societies to survive by strengthening community. So let us imagine how art making might strengthen our evolving community as we develop more sustainable lifestyles and studio practices. Thank you.

David Binns Introduction

25:47I will now introduce the second presenter on this panel. David Binns is an artist, potter from North Wales. He lectures at the University of Central Lancashire in Preston, UK. He is a member of the International Academy of Ceramics. He has worked in numerous collections around the world,

26:19and recent selected exhibitions of his include exhibitions at the International Ceramics Museum in Jibo, China, the Sevre Museum in Paris, the European Work Center in Eindhoven, the Netherlands, the Museum of Art and Design in New York, the World Ceramic Museum in Fuping, China, and the Gardner Museum in Toronto, Canada. And thanks, David, for coming all the way from the UK. I saw David give a presentation last year in Sweden

26:51and asked him to participate.

David Binns Presentation

26:54Thank you very much, Nancy, and good morning.

27:01Well, just thank you again for coming along on this damp morning. It's home from home for me, the weather here you've got in Seattle today. Hello, it's sunny back home, apparently. I, as Nancy just said, I teach at a university in the UK, and I have my own studio in North Wales, actually, which is another country aside from England. And I spend my time in my own studio making my own art, and I teach, and I am quite heavily involved in research at my university. And my practice really has been sort of very much informed by my research,

27:35evolving research, over the last number of years. And my interest has gradually evolved into this sort of strong interest in sustainability, sort of through the sort of raising consciousness of sustainability issues politically and socially. And I feel it's important to embrace those within our own sort of art practice. So what I'm going to talk about today is the sort of journey I've made to this point of finding sustainability, perhaps it's very, very important in practice, and hopefully a methodology that will allow us to be more sustainable in our art practice in the studio.

28:10But it's also very applicable to manufacturing on a large scale as well as a small scale, because I'm starting to work quite a lot with industry, as you'll see. So this is basically the journey through to this point of being very involved in sustainable issues within ceramics. So just to give it some sort of context, as artists and architects, designers, we all are striving continually for new forms of expression, new ways of expressing our creativity.

28:40And in order to do that, we are often searching for new materials as a way to sort of sustain our creative aspirations. So whilst this is encouraging the development of new materials, it also creates a sense of want of sort of environmentally unsustainable materials. Yeah, it perpetuates this sort of cycle of want really of materials which makes our practice sometimes unsustainable. And whilst there is a growth of new materials out there, a lot of new eco-materials that are being discovered and developed,

29:12this area is still in its relative infancy. And many artists within the construction industry as well still rely very heavily on virgin materials. That's materials that are dug direct from quarries and mines and things, most of them being non-replenishable from quarries and mines around the world, and also incurring lots of embodied energy in the transportation around the planet. So lots of issues of sort of problematic sustainable situations out there that we're involved in.

29:45We as potters consume a lot of virgin materials and we create quite a lot of waste. And the sort of things that we are creating waste are, you know, we all produce seconds which are unsellable, which tend to end up being just thrown away. If we're using glaze, we have glaze slot waste. We have broken kiln furniture occasionally. We have to reline our kilns. There's lots of situations where waste material is generated within our practice. And what I've got today is hopefully a methodology to try and make some use of that,

30:16to make our practice more sustainable and actually to create potentially new products out of those waste products. In the UK and in Europe, there is strong government policy relating to the sort of recycling of waste materials, great aspiration to try and make use of this sort of waste that is out there. So government policy, one, the sustainable management of waste, whilst acknowledging waste as a fact of life, the DEFRA, which is a government agency, states sustainable management of waste,

30:48optimising recycling and use is a very core part of government policy. And the Commission for Europe Communities also states or argues that waste is an environmental, social and economic challenge, but offers new opportunities. So again, what I'm proposing is building on those statements there and discovering a new opportunity for us to make use of some of the waste material we generate. So what I'm going to talk about now is this journey towards a solution.

31:20I'm going to give it some context in talking a little bit how my practice evolved and how it's changed from a non-sustainable approach through to hopefully a very sustainable approach and a methodology that we can all potentially adopt within our practice. So just going right back in time to my work, I've always worked with unadorned, unglazed clay. So glaze hasn't been an issue to me in terms of the potential waste of that. I started out by making objects that were just pure clay forms in varying different bodies, terracotta, porcelain.

31:56And one of the processes of refining was to actually sand back the surface post-firing. What I discovered was that this revealed a sort of texture in the clay body, a geological texture, which I decided I wanted to capitalise on. So this was just using found clay bodies, brick clays and heavily sort of shimato grog bodies. From that, I started introducing and developing my own aggregate materials to add to the clay. Like I said, I wasn't interested in adding any glaze or further adornment.

32:30I wanted the body itself to speak and to have all the visual properties and sort of engagement, visual engagement, aesthetic qualities of the pieces. So they were basically getting the aggregate materials, finding them from ceramic suppliers, finding them myself and then actually making them myself and wedging them, adding them into the clay body and then to create the sort of visual interest in the forms. Just a couple of shots of sort of that process of making the actual grogs themselves.

33:01So there was nothing sustainable at this stage in the process. I was actually taking clay, staining the various oxides and pigments, firing it, crushing it up and then adding it to the clay body to create the sort of aggregate visual interest. So that's slide there, crushing it, sieving it, grading it, adding it sort of in a sort of fairly intuitive way at this stage. There was nothing systematic in the approach at this point. The systematic thing came later on when I started to adopt a more research orientated approach to my practice.

33:37But it gives us some idea of the process that I have adopted. An important part of the process has been the grinding and polishing back. Just as a stone finisher would work on a piece of sort of unfinished stone. Polishing and grinding the surface to shape the form, refine it and start to reveal the sort of textural qualities that were embedded within the form. Just a slide there of a few of the sort of surfaces that I was creating at that time. And a few of the images of the types of work that I've been developing. Very, very simple forms that rely quite heavily on the surface qualities of the clay body.

34:13And what is on the surface is right through the entire core of the piece. That's a fundamentally important sort of theme within the work. And then I started realising that I could use more and more found materials. Going out to beaches, to quarries and just finding the sort of waste material that was lying around there. Again, not that concerned at this stage with the sort of sustainable issues. Just the interest that you could embed material from a particular place and put it into work.

34:43So that piece of work had a resonance or echo of the place that it had come from. So the piece there was beach shingle from a local beach close to where I live in North Wales. And then the grinding and polishing revealing those sort of pebble qualities within the forms. Then continually striving for a sort of greater variety of surface quality. It struck me that I could start introducing glass forming materials into it. Small nuggets of glass initially. Gradually introducing more and more of this glass quality to the mix really.

35:18So I was starting to formulate a sort of research question in a sense. Could I actually create something visually interesting with this combination of ceramic and glass materials? So I did a significant number of tests and started to discover that I actually was creating something quite new and different here. And the amount of glass was gradually introduced was more and more set to the point where I was actually eliminating plastic clay completely. So I now had a material that was a combination of pre-fired mineral aggregates or ceramic aggregates combined with the glass material.

35:53And the glass on melting and fusing was bonding together all the aggregate materials. And then on grinding and polishing revealing this sort of new surface which was quite unlike any clay surface. In some instances as the example there the surface would bubble up creating an interesting sort of quite dynamic surface. And depending on the materials that are added what you actually sort of got some were sort of quiet and more functional flatter surface. And some were very sort of bubbly and exciting. The process involved basically making the shape in just a neutral clay to start with that was later eliminated.

36:30So I was making a sort of sacrificial mould, making the shape, putting a mould around. Because the whole thing, the whole cast would go in a kiln, very much akin to kiln casting of glass. Then the mould would be filled with the various mixtures and the blends of crushed glass, some glazed waste slop and the aggregate materials. That would be then placed in the kiln, fired in situ in the mould and then the mould would have broken out revealing the actual piece.

37:00And then there was quite a large process of cutting, grinding and polishing to actually expose and shape, refine the shape of the finished piece. Another example there. And you can see in that piece there the sort of, because the mix was marbled, you get areas that are quite glassy and you get areas that are very intense in the sort of textural qualities of the aggregates. What I also started to discover was that you could, in conventional clay, you can probably only put a piece of pre-fired material up to about five millimetres, a quarter of an inch or so in size, into the clay.

37:33Because the plastic clay will shrink around it. This process that I was seemingly developing allowed me to put a lot larger pieces of pre-fired material into the pieces. So it, again, allowed all sorts of new sort of creative opportunities because you could put great big chunks of material in that almost became sort of fossils within the piece, really. Because when it was fired, the material flowed around it. There was no expansion and contraction as you get with conventional clay. So you see a shot of the sort of qualities of the surface that were evolving.

38:06And also you could slightly see into the surface as well. Again, it had a very dynamic quality, unlike the opacity of conventional fired clay. So I developed that for a period of time. Again, very much just relating it to my own artwork, trying to capitalise on the qualities of the material that were emerging. Alongside that, my teaching, I was supervising a number of PhD students. And one in particular, a colleague now, Dr. Alistair Bremner.

38:36He was working at the time on refractory concrete, which is a high-fired concrete used more often than not for lining of high-temperature kiln furnaces for the chemical industry and for steel founders. And together we started collaborating on a number of projects. We set up a research centre at the university. And we collaborated on a number of large-scale projects. And started, at the same time, I started realising that the materials that I was using, there was a possibility of substituting them for recycled materials.

39:12Because the realisation that the bottle banks collection of waste consumer glass from the curbside collection, vast amounts of glass out there. The ceramic industry were generating huge amounts of waste, some of which was being recycled, but a lot going back into landfill just as a sort of inert waste material. So that was just starting to raise in my consciousness that there was this opportunity and slowly started to introduce some of this material.

39:42And started on a few projects that would start to use and integrate this waste material. So this was a small prototype table made, not the frame obviously, but the top made entirely from recycled materials. That was a combination of waste glass, waste glaze, and waste ceramic aggregates crushed up. And into it, I don't see the sort of fossil-like elements were second quality bone china tableware that was bedded into the mixture pre-firing, post-firing.

40:12You then could grind them back and reveal the sort of outlines of the tableware in the piece. So all sorts of exciting sort of creative opportunities were arising from that. We also worked on a joint project. We had a commission from a garden designer to create some large-scale sculptural forms. So I was now collaborating more and more with Dr Bremner. These were about 250 kilos each, I don't know what that is in pounds, but large concrete cast forms.

40:42But the aggregate material was waste material that we've been finding from, it was mainly quarry waste actually that was added to these, to the concrete mixture. And fired and then installed in this sort of gardens, working with a garden designer. So all the time this idea that waste materials had this really interesting opportunity to develop more seriously. So we applied for a research grant from the UK Research Council, which we titled The Aesthetic of Waste, An Investigation of the Creative and Commercial Potential of Kilncast Recycle Mineral Waste.

41:18So it was a two-year project to investigate this more seriously. And the sort of basic aims of the project were firstly to actually identify and source recycled mineral waste materials. To explore how they might be combined within this sort of fusing process to develop something that added value to the original low-value waste. And to create something that had some sort of unique aesthetic properties. And to also examine its potential creatively and commercially with architects, designers, craft makers.

41:52So it was the three major aims of the project. The sort of materials that we were looking at were the recycled waste glass, waste from quarries. Brick waste from sort of buildings that have been dismantled and knocked down. So the masonry from buildings. Tableware waste from the ceramic industry. Sanitaryware waste. Again, I didn't realize that the sanitary air industry has about a 20% waste or loss that more often than not ends in landfill. Foundry slag from iron and steel foundries and power station waste.

42:25There was a whole range of waste material out there, most of which was just ending up in landfill, very low value. So this seemed like a great opportunity to explore. And within our own studios, small-scale studios, we, like I said at the beginning, we do generate a significant amount of waste. Just a shot there, damaged kiln furniture, glaze slop, seconds. A lot of stuff that probably at the moment just gets thrown out into a skip and eventually landfill. So this is our raw material for our project.

42:55We managed to actually get hold of a crushing machine, which has certainly helped the project. These are machines that aren't that difficult to get hold of. That allow you to convert back the material from a large state to a small granular state. You can control the grain size of it. But it allows you to convert any amount of stone, ceramic, mineral waste back down to an aggregate. That there, believe it or not, is a huge sort of swimming pool of glaze waste from a ceramic manufacturer in the UK.

43:27They generate, and one of these big swimming pools of what they call pontoon, what's the official name for it. But they are basically hundreds of gallons of glaze waste generated every week that just gets sucked out of that filter pressed and thrown into landfill. So we're surrounded by all this waste material. Where I live in North Wales, it's got a huge history of slate mining. There are masses, millions of tons of slate waste lying around.

43:59Down in Cornwall with the China clay industry, there is millions of tons of spoil from the China clay industry. So a huge amount of waste out there. Again, all part of our own material. So we started collaborating together, Dr. Bremner and I. We started collaborating with local industry. We were making sort of prototype products combining our two materials. Dr. Bremner's refractory concrete with my glass material. We engaged a material scientist to start investigating our material in depth.

44:35He would analyze our raw materials that we were finding from the quarries and the ceramic industry. And then he would reanalyze the materials. Once we fused together these different materials in varying combinations, he would then do another further analysis on them to check for strength, porosity, to basically sort of confirm the functionality of the materials that we were developing. And it was a sort of interesting experience moving from the ceramic studio into the science laboratory and spending time looking down the electron microscopes.

45:07The images you can see there, the colored image in particular, shows that the yellow area is the glass element, the glazing glass element, and the purple area is the sort of small chunks of ceramic aggregate. So what he was allowing us to discover was the interaction between these sort of particles and check the strength and the sort of fusing properties of these materials and confirming, like I said, that we have a functional material in place. We engaged in a number of quite interesting projects.

45:38This is a project we did with the AKWC in the Netherlands, which was a project called Brick. And it was basically to develop prototype, innovative sort of architectural products. So we developed cladding brick that had some elements of the refractory concrete and then quite large elements of the recycled glass material in it. So there's the cladding brick and then there was the six panels of material

46:08that involved quite a lot of recycled material within them. The central ones, the six, were entirely made from recycled waste. So we had large panels now we're creating, half-metre-square panels made entirely from recycled waste. We then were, with these sort of new materials, new products, we got involved in a number of interesting exhibitions and other projects. This was a project called Object Factory, which was two exhibitions, one in Toronto at the Garden Museum and one at the Museum of Art and Design in New York.

46:40They were basically exhibitions to sort of expose new innovative ideas in materials and technology within ceramics and design as well. There's another example of a large cast slab. So we were now able to find we could make things up to about a metre square. This was a large slab of material. The dark pieces are a stained ceramic that we just had lying around in the studio

47:10with some waste second quality from some student work which we crushed up. The rest of it is entirely made from recycled quarry waste and glass and glazed slop again. And this is a shot of a number of samples of different qualities that we could get from it. At the least, they were 97% recycled. The colour variation was by adding small amounts of ceramic pigments, but really just tiny, tiny percentages. And we're looking all the time for finding waste supplies of that

47:43so we don't have to rely on any sort of virgin material at all. So we found we can create a large palette of textures and colours with this process. And that's a close-up example of one of the pieces. Again, the yellow pigment, the rest of it is all recycled material. And a further example of the sort of close-ups of some of the qualities we can achieve through the recycle. The pink one is 100% recycled and the other three are just with 1 or 2% non-recycled material.

48:17So the reliance on virgin raw materials has become very, very diminished really. This was a tabletop that we produced, two metres by one metre square. So we tried to push the boundaries of the process all the time. We felt that scale was important because we'd had this idea that we could even sort of expand into making kitchen worktops or counter surfaces with lots of sort of exciting possibilities for working and collaborating with architects and interior designers.

48:47So the sort of the main environmental aesthetic advantages of this material are, like I say, it's a sort of minimum of 98%, often 100% waste. It directs low-value waste away from the landfill. So all that stuff that was being generated by the sanitary wear industry and the sort of glazed pools that was waste from the tile factory, potentially we can avoid that going into landfill with this process. And as a sustainable alternative ceramic tiles or imported sheet stone, it has a number of advantages as well.

49:23Because a lot of those materials are transported large distances across the globe. I mean, there's a store in my local town that's just had a re-clad wall. It's clad with Vietnamese stone. So they're shipping in thousands of tonnes of this stuff around the planet. We can use locally sourced raw materials to avoid any of that moving across. Avoids using non-replenishable virgin stone raw materials and avoids that sort of potential environmental damage caused through quarrying and mining.

49:54We're trying all the time to lower the temperature dramatically. There's no annealing in it, unlike glass. So we're reducing our sort of carbon emissions within the firing process. It can be engineered to a client's requirements using local materials. We can reuse all the waste within our own process so we can put them back into the system. And at the end of life, the material can go back into the system again. We could take it off a building, we could take it off a work surface, crush it up, put it back into the process.

50:24I realise I'm running a bit short of time now. Just a couple of more examples of there. Large slabs using the sort of cup fossils. Some shots of recycling the recycled. So this is material that's been gone through the process two or three times. And right up to now, we are now working with a local recycling company setting up a small pilot manufacturing plant to actually start mass producing on a sort of small scale these tile-like products

50:54with view to launching a range of products commercially. And this is an example here of, on the left-hand side, it's our cladding tile. On the right-hand side, the stone imported from Vietnam. So we're able to replicate a lot of the sort of stone qualities. And then finally, it's just also back-informing my art. So the research and the sort of my own practice are sort of very much interdependent on each other. Just a couple of slides of work that predominantly utilises this material.

51:26That is 100% recycled, that piece with the fossils. The other shots that some use, because I've also found I can combine it with clay. I can fuse it against clay as well. So just a couple of shots of some of the more recent pieces of work that are combining the two materials together. Okay. I think that's it. Thank you.

Guido Stribos Introduction

51:55And now I'd like to introduce the final member of our panel. Guido Stribos lives in the Netherlands. And he will correct my pronunciation, but it's like vanhoek. No G's are the. He received a master's degree in material science from the Technical University of Delft. He has experience working in a variety of technical industries, steel making, engineering. You guys shouldn't leave.

52:25This is really important. Steel making, engineering, medical industry, and composites. Now he's working with Hrad Blau as a co-director of Blau Products, which is an innovative company outside of Amsterdam that has designed and built hundreds of custom energy efficient computerized kilns for artists, universities, and industries throughout Europe, North America, and Asia. So thank you for coming all this way.

Guido Stribos Presentation

52:56Thank you, Nancy. Well, it's a pleasure to be here. Well, it's a pleasure to be here. I've never been to Seattle. I've never been to the NSECA. It's my first time, but I enjoy every day I'm here. So thank you for being here. My presentation will be about 15 minutes, so I hope you have the energy left to listen to that. Maybe I can give a short introduction to the company I work for. After that, I will talk about sustainability in the sense that we're looking for energy savings. Blau Products is a company based in the Netherlands.

53:27We're quite near Amsterdam in a small town called Lonsmere, five minutes from Amsterdam. What we do is we think, design, make, so we don't do anything standard. A customer comes to us, explains his dream or his vision. We start to think about it, design the solution around it, and we make the kiln. We have about 35 years of experience building kilns. We make fully automatic gas and electrical kilns and related equipment for the ceramic industry, but also the educational industry like universities, art centers, potters, and so on, artists,

54:00and also for the glass industry. We also have a booth here, so if you have any questions after the presentation, I'm happy to answer that also in the booth. Some examples, what we did, you see some kilns at NASCAD University in Nova Scotia, Canada, some kilns in Singapore, and some ideas of what we're doing for our customers. So, my presentation is called Less is More. I think by doing less, we can have more in that sense. So, of course, real sustainability is not using any energy during firing.

54:34That's impossible, of course. So, if you look at the energy consumption in the whole process of making a ceramic, one of the biggest energy consumers is the production and firing of the kiln. You see there a picture of, which is not really, let's say, suited for a kiln, because you see there's also a conveyor loss and a radiation loss given there, because it's an automatic process, which is continuous. But what you see is that the amount of energy you put into a kiln, that about 50% is just going out of the chimney.

55:08About 10% to 15% is going into the walls of the kiln. About 10% to 15% is going through the walls of the kiln. And the rest is for your wares. So, it means it's quite energy inefficient in that sense. So, I think we should be looking at getting all the energy which you put into a kiln to get it into the wares as soon as possible. And I think if we use our fossil sources in a sustainable way, we should focus on using less of these sources.

55:39So, if you look at the sustainability in today's ceramics, I think if you look at the industry, there's a driver for cost reduction, hence energy consumption savings. They have to be cost effective. They have to compete with other industries to make their products cheaper and cheaper. So, these people are looking for new technologies to save on energy in that sense. I think that the educational industry like universities and art centers, they like these drivers.

56:10There's no need to compete with each other. There's no real need to reduce energy consumption. If some universities told me they don't even see the gas bill. So, they don't know how much energy they use. And I also got the feeling, and I don't want to hurt people with saying this, that ceramics also are based on the romantic culture, and not always on current available technology. Of course, I understand that building a kiln with hard brick or soft brick, or going into the woods to get the wood for the kiln.

56:43It's nice to do. And sometimes it's also very economically to do if you don't have the money for a kiln. But if you look at the efficiency, of course, it's better to have another option. So, I would like to show you the current available technology, which is more and more adapted by the ceramic industry, to have it also being available for the educational industry. So, to my opinion, ceramics should adapt and invest in new energy-saving technology methods.

57:14It means more or less a cultural change. And these things, of course, will take some time. So, the message I would like to bring today is, maybe it's, of course, the first one. It's a little bit difficult to say, to polish. Well, it's like, to fire or not to fire? That's the question. Should we fire everything we make? I think Nancy showed some examples of unfired ceramics, which, to my opinion, were quite beautiful. We should try to use energy sources as direct as possible, without any transformation in between.

57:44I will give you an example of that later on. We're looking at redesign of firing curves. There's a lot of energy consumption to save and to gain there, by looking at your firing curves and optimize them. Also, the use of highly insulated material in kilns can save a lot of energy. We're looking at efficient combustion, and also to use the heat, which I showed you in the picture, is going out of the chimney, to reuse that within your kiln room or within the factory.

58:14So, the first thing is, should we fire anything? Well, of course, not firing is the best energy saving, but that's maybe a strange thing to say. And I think it's good that I mentioned that. So, I think everybody should consider the educational value of the firings, and the glazing stages. Is it really necessary to do the same glazing all over again, to show the students what is happening? Is it really necessary to fire, to learn something? And maybe there's a possibility to develop alternative student programs

58:44for developing taste and feel for form and color. Something maybe to think about. The direct use of energy. Here you see the ideal Dutch cow producing gas, which is, let's say, directly transformed to energy, to electricity for instance. Of course, in real life you don't see this, because when you use gas to make electricity, you lose about 50% in the transformation process just by friction and heat.

59:14So, if you have natural gas or other gas available, the best thing is to use it in a direct way to heat up your wares. Of course, if you have electricity available in states where, for instance, you have hydropower, of course it's a very good alternative. But if you start to transform gas into electricity by gas turbines, it's a very inefficient process. So, in our view, use the fossil source as direct as possible.

59:44Another thing is the redesign of firing curves. A lot of the current technology in clay and glazing recipes, they allow for faster firings. They also allow for lower firing temperatures. You have to explore what is possible. Sometimes it's just enough to do a natural or a forced cooling with a kiln instead of down firing. It's just a matter of trying to explore your limits, what is possible and what is not.

1:00:14As an example, about 10 years ago, some tile makers used about 60 minutes to go to cone 10. And now we have seen examples of people who do it in 30 minutes. By exploring new recipes, by exploring new firing curves, because there's new technology available. So, you could save a lot of energy in that sense. Here's an example of a company, Archie Bray Foundation, which has been monitoring all of their firings, different firings which you see. You see cone 7 reds, you see cone 10s, you see cone of 4s,

1:00:47and you see the gas consumption there. So, they're really monitoring what they use per firing, or what kind of sort of firing. And from this picture, they found out that some cone 4 firings, for instance, use more energy than a cone 10, which you maybe not expect. So, then they start digging deeper into that process. So, they took a cone 7, and they start to fine tune it. So, the first firing they did, they had this gas consumption that put a figure in 6.07.

1:01:20And they tried to redesign the firing curve. Maybe go faster, because the faster you go, the less time you have, and the less energy you use. Or maybe go less in a certain time frame. So, in the end, after about 11 attempts, they managed to bring their gas consumption down by half of it. So, they are now at 3.02. Which, of course, is a big saving. Just by trying and optimizing their firing curve.

1:01:47Another thing is that I think we should promote the use of highly insulated materials. To give you some example, let's say the traditional type, and of course many kilns, very good kilns are built with brick. Which is a good material to use. But I'll show you what happens if you use another material like fiber. In terms of energy consumption, and energy going through the walls. Here you can see some graphs that are taken from an engineering guide from Eclipse Burner Manufactory.

1:02:18You can see on the left-hand side, you can see the heat losses from a refractory. Different kind of refractories. You see hard brick, you see soft brick, you also see a castable, you see soft brick, and you see fiber. What these graphs show you is that a hard brick, for instance, there's a lot of energy going into the hard brick. So what you do is by putting energy into a kiln, you heat up the hard brick, or you heat up the castable or soft brick.

1:02:48And the more you heat that up, the less it's going into your wares. So what you would like to have is a material that doesn't heat up or doesn't transport the energy throughout the kiln, but just keeps it to your wares. So here you can see what the differences are in these kinds of materials. You see, compare fiber to, let's say, a hard brick. It's, I think, a factor of 10 or 15, which you lose. So in a sense, by using materials that are more insulating, you can save a lot of energy by just putting all the energy into the kiln directly into your wares.

1:03:24And also what you can see is that the storage of heat into the kiln, it means that it takes a time before you can really heat up your wares, because first you have to heat up the kiln, and of course that's what you don't want to do. Some figures on energy cost savings we have seen. Here you see an example of the cost savings from a fiber versus a hard brick kiln. These were two different sizes of kilns, so we made a sort of recalculation on that. But what you see is that the traditional hard brick kiln uses about $85 for firing,

1:04:01and the fiber kiln uses about $32 for firing, so it's a saving of about 60%. Of course, the more firings you do, in this example, we took a certain amount of firings per week, a certain amount of weeks per year. You can see that in this example, the savings per year with the current gas price is about $13,000. Of course, we know that the gas price only goes up in the coming decades,

1:04:32because the resources of gas, in the end, are running out. So these savings will even be larger in the future. Another example is Nescat in Canada, where they have an old hard brick gas kiln, which costs them about $200 in gas, plus overtime to pay the technician to stay up all night long. It took about three days, and the results were never the same. This is a quote-unquote. Now they have another kiln, which costs them about $20, and they fire it in by 14 hours, which, of course, is a big energy saving in that sense.

1:05:07Another thing you can do to further improve the energy savings is to put a reflective coating on the fiber. These coatings are in the market. They're available. It's a zirconium oxide-based coating, which can be applied by spraying. The industry uses this a lot, because it further improves the energy consumption of these kinds of kilns. It also protects the fiber from the environment. It gives a very abrasive surface.

1:05:38Another thing we're looking for to reduce energy consumption during firing is efficient combustion. I think we should use the most efficient burn system there on the market, like a closed system with high velocity, where you get a lot of draft in the kiln, a lot of velocity in the kiln to heat up your wares. You should do a very correct calibration of the kiln, so you make sure that in every temperature segment where you are in the kiln, if it's low temperature or high temperature, that the amount of gas and air is optimal, so you take the most energy out of this mixture,

1:06:12instead of having too much gas, too much air, of course, unless you want to do an oxidation fire or a reduction fire. Another thing is that the heat the kiln produces, you should reuse that to preheat the air, because it makes the combustion even more efficient. I've shown you this picture before about the heat that's going out of the chimney. So the first question I had, why not use it? You have different kind of recycle options in that sense. You can use the heat to preheat the kiln combustion air for more efficiency. So you see this schematic picture of a kiln with a chimney on there.

1:06:46So the hot flue gases go out of the chimney. So halfway, there's an outer chimney with openings for, let's say, cold air taken from outside. It's being pulled downwards. So you have a flow going upwards with warm air and a flow going downwards with cold air, which is heated up. It's going through the blowers inside the kiln, and it can make your combustion even more efficient. Another option is to use the heat in that sense, not for your blowers, but for instance, for the hay vac system of a building.

1:07:20Like at AKVC in the Netherlands, they use the heat for their kilns. They use it also to heat up the building. Another thing is that you can also use the heat, if you have a drying chamber in your process, to use it there. So there are many options also to use this 50% what's going out of the chimney to reuse it. So to summarize it in that sense, by saying less is more, I think less firings, think about the educational value before you fire.

1:07:52We have less waste and energy transformation by using direct usage of the fuel we have in this term gas. Try to use less firing time, faster and efficient firing course by redesigning. Do some research on the firing you should have. Try to use less heat, or try to have less heat loss during firing by better insulation. Have less waste and combustion, use efficient burners. And have less waste heat by recycled heat you have, which is going out of the chimney.

1:08:25I would like to thank you for your attention. To see additional content from our conference, please visit our YouTube channel. You can also join our online community on Facebook and Instagram, as well as other major social media platforms.

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