Epicurean Cast | Sonia Tereszczenko
The Master of Science concentration in Digital Technologies (MS_DT) was initiated in 2011 as a post-professional degree that offers motivated participants the opportunity to investigate design practices and conduct independent research in computer-aided-design and advanced fabrication techniques. Project-based research provides a â€œtesting groundâ€? for new modes of practice and innovative uses of existing, new and emerging technologies. The program builds upon a tradition of cutting-edge technical research at Taubman College, the University of Michigan, and in the Detroit region. University of Michigan offers unmatched excellence in digital fabrication and access to world-class lab and production facilities and regional linkages to industry. Each issue is assembled by the individual author/architect during their duration at the University of Michigan.
Epicurean Cast Sonia Tereszczenko
2012 Karl Daubmann (MS_DT Coordinator) Mark Meier Jason Prasad Mat Schwartz Ryan Shaban Fausto Teran Sonia Tereszczenko Aaron Willette Robert Yuen
Master of Science in Digital Technologies
MS_DT A. Alfred Taubman College of Architecture and Urban Planning University of Michigan
Epicurean Cast by Sonia Tereszczenko Masters of Architecture, 2010 University of Michigan Bachelors of Science in Architecture, 2008 Lawrence Technological University Submitted to the Department of Architecture and Urban Planning in Partial Fulfillment of the Requirements for the Degree of Masters of Science in Digital Technologies at the Taubman College of Architecture and Urban Planning June, 2012 ÂŠ2012 Sonia Tereszczenko, All rights reserved. The author hereby grants to the University of Michigan permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part.
Signature of Author
Epicurean Cast by Sonia Tereszczenko Submitted to the Department of Architecture and Urban Planning June, 2012 in partial fulfillment of the requirements for the degree of Masters of Science in Digital Technologies
ABSTRACT Epicurean Cast explores the use of digital technologies in close coordination with the human hand in the production of the final product. Formally, the work explores the translation of the human body and its sensual qualities into a terra cotta column.
Table of Contents Introduction
Ornamental Precedent Barcelona Pavilion
Herzog & deMeuron
Technical Precedent Mario Botta
Ornamental detail in the Roman Forum, Rome, Italy
For thousands of years, ornament has played a strong role in
architecture. Various cultures carved their gods in stone and adorned their buildings with symbolic references. Ornament has provided a way for architecture to have a strong connection to the natural world, transforming hard materials into the soft and organic forms of nature, including the human form. Ornament has evolved with great speed over the past one hundred and fifty years. In an attempt to remove taste and subjective opinions from the criticism of design, guidelines were created to make design more of a science. The rise of the middle class during the 1850â€™s and their influence on the consumer market of art changed the dynamic between designers and the products produced. Designers and the middle class did not agree on what was considered good taste. In turn, designers revolted against the middle class and established guidelines that could not be judged based on subjective opinions.1 Guidelines for design were developed and, â€œDesigners made it increasingly difficult to talk about the beauty of a design . . . Buildings were not beautiful . . . Instead . . . they appealed to our intellect and sense of morality: we were to appreciate their honest expression of structure, function, material, and so onâ€?.2 Ornament in architecture changed drastically, stripping the symbolic meanings and applied relief of surfaces, resulting in the glorification of the pure materials and structure of the building. Modernism was the pioneering style in the removal of ornament, and its effects in the architectural styles of today are still prevalent. Although modernism claimed to remove ornament, it was actually redefined. Ornament was included in modernist architecture through the textures provided by specific material selections.3 Materials were exploited for their unique qualities, providing
architecture with a layer of ornament integrated within the material itself. The research of â€œDancing Ladiesâ€? stems from these ideas of texture within architecture and develops them in a way which represents a soft, supple form with sensual and feminine qualities in terra cotta. It is the goal of the work to use digital technologies to explore various techniques and new opportunities for ornament in architecture in the twenty first century.
Before the industrial era, architecture had taken years, even decades
and centuries to design and build. In the current world, technological advancements have aided in the ability to decrease design and construction time. Buildings can be assembled in only a few months and the turnaround rate is nearly comparable to that of clothing. Digital technologies have been a growing part of the profession and are allowing aspects of design, like
Masonry in the Colloseum, Rome, Italy
ornament to be more affordable. Andrea Gleiniger writes about the cultural significance and meaning of ornament in her essay “New Patterns? Old Patterns? On the Emotional Appeal of Ornament” and she says that: What Michael Muller established in 1977 in relation to Heide Berndt seems far more applicable: namely “an architecture that aspires to develop an ‘aesthetically innovative and psychologically, highly differentiated formal language,’ in other words, also a type of ornament, to account for the technical state of its available materials,” and thus to “measure the future design of architecture [...] against the current availability of technological developments and possibilities”.4 The design of ornament should be exploiting the technology that is available. Fabrication techniques that did not exist one hundred years ago are easily accessible to many designers today. This provides the current-day designer to use these technologies and develop new ornament or ways of producing ornament that were not previously available in history. Ornament has been grounded in similar building techniques for hundreds of years and the shift into the digital age provides an opportunity to break away from convention and develop ornament in a way not conceived of before.
The project will explore the aspects of ornament through the design
and fabrication of architectural columns. It is the goal of these columns to create an architectural design in a hard material which has the soft characteristics of the human form and is in a constant state of visual motion. Terra cotta has been chosen as the project material due to its strong historical use in architecture. For centuries, terra cotta has been used in architecture, most commonly known in the form of a brick, d ue to its malleability before
firing. Terra Cotta also has the ability to take on the form of almost any design. This project takes advantage of its malleability and transforms it into a hard, durable, and fire resistant column.
The fabrication of these columns unites the process of digital
fabrication with the need for the human hand. The digital fabrication process itself does not produce the final product, but is used as a part of the process in the design and manufacturing of the columns. Terra cotta is not a material which can be machined, but through this process it is given the detail and complexity of a digitally manufactured element. This project works to unite the processes and give the use of the human hand a strong role in the production process.
1. Brolin, Brent C. Architectural Ornament: Banishment and Return. New York: W.W. Norton & Company, Inc., 2000. 2. Ibid, 15. 3. Kolarevic, Branko and Kevin R. Klinger. “Manufacturing / Material / Effects”. Manufacturing Material Effects: Rethinking Design and Making in Architecture. New York: Routledge, 2008. 6 - 24. 4. Gleiniger, Andrea. “New Patterns? Old Patterns? – On the Emotional Appeal of Ornament”. Pattern: Ornament, Structure, and Behavior. Ed. Andrea Gleiniger and Georg Vrachliotis. Basel, Boston, Berlin: Birkhauser, 2009. 13 – 24.
Brick at the Castelvecchio Museum in Verona, Italy
Ornamental detail in the Roman Forum, Rome, Italy
Historically, ornament was created based on religion, heritage or
culturally significant symbolism. For example, in ancient Greek architecture: The Laurel and the Olive owe their introduction into ornamentation to their symbolic significance. Both played a conspicuous part in the tree worship of the ancient Greeks. The Laurel was sacred to Apollo. It was the symbol of atonement; singers and conquering heroes were crowned with it; and in a similar sense it is still used as a symbol of glory. The Olive was sacred to Athene; Olive branches were the prize of victory at the Olympian games... The Olive branch is the symbol of peace.1 In the United States, the extreme diversity does not allow for ornament to be based on these types of cultural backgrounds. Farshid Moussavi says that, “It is clear that in a multicultural and increasingly cosmopolitan society, symbolic communication is harder to enact as it is difficult to gain a consensus on symbols or icons. Representational tools are less coded and unable to produce convergence with culture”.2 The culture of our current time is changing with rapid speed and it is difficult to define due to the frequency at which it moves. Designers need to define the aspects in the current society to explore and dissect in order to develop architecture which is relevant to our current time. Mousavi says that, “The dynamic nature of culture requires that buildings each time define their own ground and develop an internal consistency. It is precisely through these internal orders that architecture gains an ability to perform relative to culture and to build its own system of evaluation”.3 Furthermore, cities have created micro cultures that have detached people even more from their personal backgrounds. James Holston and Arjun Appadurai explain that, “A new generation has arisen to
create urban cultures severed from the colonial memories and nationalist fictions on which independence and subsequent rule were founded”.4 As people move into cities, their cultural backgrounds are blended with the culture of their adopted home. As various backgrounds come together, adaptations occur and new cultures are created, resulting in neighborhoods with distinguishable qualities. This further increases the dilemma of creating ornament that is culturally significant because of the merging of cultures, adaptations and certain omissions of various backgrounds. When ornament begins to tap into the micro cultures and be influenced by the adaptations to a number of cultures coming together, design decisions will be influenced in a way to create an ornament that is unique and speaks to a large group of people, no matter their independent backgrounds.
While the formal aspects of ornament tap into certain qualities
of culture, the choice of material influences the overall feel of the design. Materials also have certain connections to various cultures, and one which has been used for millennia in all parts of the world is terra cotta. It has been used to create shelter, make pottery, and keep impeccable archives of the past, resisting the harsh conditions of the natural world. The origin of the name, terra cotta comes from the Italian renaissance and when translated, literally means “cooked earth”.5 It is the oldest known manufactured building material known to man and, “The earliest reference to the use of burnt clay as a building material is to be found in the Eleventh Chapter of Genesis, in the connection with the building of the Tower of Babel.”6 The Romans and Greeks used terra cotta for a wide variety of uses but at large scales for the ornament of their buildings. Often chunks of stone would be used as
Guaranty Building by Louis Sullivan
the framework of a building, and the molded terra cotta pieces would be fit overtop with the decorative detailing. The chosen material to be worked with throughout this research is therefore terra cotta because of its strong history in architecture spanning various cultures and the endless possibilities in its final form.
Terra cotta provides many benefits to using it in architecture such
as its resistance to decay. For example, â€œThe capitals and other work in the oldest part of Buckingham Palace were made there [London, England], and although the stone work of this palace on all sides shows great signs of decay, the terra-cotta Corinthian capitals are as sharp as when they left the kilnâ€?.7 There are many examples of terra cotta details being found in
similar condition, resisting weathering extremely well compared to other building materials such as stone. Also, due to the process of manufacturing terra cotta, it is fire resistant. Compared to other materials which will crack or begin to bend under high heat, the firing process of terra cotta is what gives it its strength, thus making it a strong material under extreme heat conditions. Because of the ability to resist fire, terra cotta became a valuable building material in growing cities where fire damage had been extensive.
With such a long history of terra cotta being used in the world, it has
a rather short history within the United States. It was not until the mid 1800â€™s that terra cotta began to be used in cities such as New York and Chicago. The growth in popularity of terra cotta had a difficult beginning, as James Renwick explains in a letter from 1886: In 1853, I conceived the idea of introducing terra-cotta as a building material and substitute cut stone work in New York... I supposed it would be a source of large profits to him [Mr. Young, owner of a sewer pipe factory], as it would be more durable and ornamental, and less expensive, than the free stones which were in use... We tried to introduce it into general use, but were violently opposed by the stone-cutters and builders who said it would not stand, and persuaded owners not to use it... The fact is, we were ahead of the times, and could find no one who understood or would venture to use it.8 It was not until after many major fires had destroyed large parts of several cities that the use of terra cotta began to increase. The major form of terra cotta used was brick, and the brickwork provided buildings with the necessary fireproofing.
Since terra cottaâ€™s acceptance as a building material in the United
States, many great architectural works have been built using this material. For instance, Louis Sullivan extensively used terra cotta to cover his steel framed buildings: “Sullivan’s buildings were usually decorated with tasteful ornamentation, stamped in terra cotta or steel… The detailed designs, based in nature, gave a feeling of flow and life to Sullivan’s buildings”.9 Fine detailing is attainable while working with terra cotta as the designer develops as much detail as desired. Molds can then be formed to create duplicates with as much detailing as the original. Because of its ability to be molded, many duplicates can be easily created at a fraction of the cost and time that it would take a stone sculptor to hand carve the same design.
1. Meyer, Franz Sales. Handbook of Ornament. New York: Dover Publications, Inc., 1957. Page 43. 2. Moussavi, Farshid. “The Function of Ornament”. The Function of Ornament. Barcelona: Actar, 2006. Page 6. 3. Ibid, 8. 4. Holton, James and Arjun Appadurai. Cities and Citizenship. Durham and London: Duke University Press, 1999. Page 3. 5. Geer, Walter. Terra-Cotta in Architecture. New York: Gazlay Bros, 1891. Page 4. 6. Ibid, 5. 7. Ibid, 15. 8. Ibid, 17. 9. “A short essay about the Guaranty / Prudential Building”. Louis Sullivan. “http://www.triskaidekaphobia.com/sullivan/”. Feb 5. 2012.
Guardian Building by Smith Hinchman & Grylls
Ornamental Precedent: Barcelona Pavilion
The choice of material based on color, pattern of grain, and shadow is
a way that architectural forms have included intricate detailing in architectural surfaces. Texture has various characteristics such as light, shadow, depth, pattern, repetition, and touch (smooth, flat, bumpy, rough). An example of texture being used in architecture is Mies van der Roheâ€™s Barcelona Pavilion. The pavilion had very specific material choices due to certain qualities that are inherent in the materials. Marble is used throughout as the wall material. The pavilion could have been designed with materials that had flat and uniform coloring, but instead various types of marble were used throughout with varying colors. The grain of the marble added texture and depth to the walls, creating an affect completely different than if the pavilion were made of white gypsum board. Also, the patterning of the marble that comes together to cover the walls was very deliberate. Marble pieces were cut from a single slab and mirrored along the joint line to visually look as though the veins were continuous along the entire surface. The image to the left shows the emphasis on texture throughout the pavilion. The image is black and white, removing the aspect of color and focuses on the detail added to the pavilion solely through material selection. Mies designed with ornate material selections with strong textural qualites that were inherent in the material and unable to be stripped away from the design.
Detail of the punched cladding 20
Ornamental Precedent: Herzog & deMeuron
In current architectural design, ornament is being embedded within
functional systems and is more widely accepted when it is performing a task. In an interview between Jacques Herzog and Jean-Francois Chevrier, Herzog said, “When ornament and structure become a single thing, strangely enough the result is a new feeling of freedom. Suddenly, you no longer need to explain or apologize for this or that decorative detail”.1 The De Young Museum is an example of Herzog and de Meuron’s work where ornament was an integral part of the cladding for the building. The process for the design was to take an image of the tree canopies surrounding the site and turn it into a pixilated image. This pixilated image was then used to create a series of varied sized holes and deformations in the copper paneling based on the contrast of the image. The result is a vast building enclosure with a similar affect to the surrounding trees on the site. The holes and deformations become part of the wall and not an attachment, therefore becoming more difficult to criticize and suggest that it was a superfluous addition to the building. The work of Herzog and de Meuron continually uses the technique of embedding ornament within the necessary pieces of a building, validating its use and removing many opportunities for criticism of its existence.
1. Herzog, Jacques. “Conversation Entre Jacques Herzog et Jean-Francois Chevrier”. AMC Texture Pattern. Paris: Presse Payant, 2007. 25 – 29.
2 part forms
Ornamental Precedent: Erwin Hauer
Erwin Hauer has designed many screen wall systems, all originating
from the idea of continuity within a single module. His designs include the saddle shape, using concave and convex forms taken from his studies of biomorphic form.1 His screen designs continue to develop beyond a formal artistic exploration, into architectural elements where the screens provide a diffusion of light, space separation, and in certain instances a structural system. Hauerâ€™s designs are dynamic elements which bring variation into any space. He describes the affects of Design 1: Light hitting the screen from the front accentuate the continuous, meandering linear patterns that traverse it apparently infinitely, much like the continuo in baroque music. Between these lines, in diffuse light, the surface is shaded with subtle gradients everywhere. Strong light, however, will create striking shadow patterns on the surface of the screen beyond. If the light source is the sun, these patterns will change with the hour and the season.2 The play of light is apparent in all of his designs. Also, visual effects are created, such as the illusion of change between the elements, although each of the pieces maintains the same shape across the surface.
The casting techniques and materials vary from design to design.
Some molds are made of multiple pieces and the final form is only understood once it is assembled. Other molds are made in a single piece and use cores to create the hollow forms of the cast. The molds are made of plaster, fiberglass-reinforced epoxy resin, bronze and steel. The final castings also vary in material and include Hydrostone, cast stone, injection-molded acrylic resin and cast stone grout. 1. Hauer, Erwin. Continua: Architectural Screens and Walls. New York: Princeton Architectural Press, 2004. 10. 2. Ibid, 10.
Sagrada Familia 24
Ornamental Precedent: Antoni Gaudi
Antoni Gaudi was a unique Catalan architect whose work is still in
progress to this day. His work evokes the imagination while obtaining ideas and patterns found in nature. His architecture is covered in patterns and colors, continually engaging the users of the space. His designs incorporate many ornamental elements which explore various crafts including ceramics, ironwork, and carpentry. Throughout many of his buildings, he designed curvaceous surfaces and incorporated ceramic tile. The tiles were not molded to the exact shape of the surface, but large pieces of ceramics were broken into smaller pieces where they could be mounted onto the curved surfaces.
Casa Mila 25
Alhambra Palace 26
Ornamental Precedent: The Alhambra
The Alhambra is a Moorish palace in Granada, Spain. Its surfaces
are covered with ornate detailing in plaster and in ceramic tiles. Many of the architectural features are purely ornamental and do not serve any other function. Many of the archways are unnecessary structurally, but are used as ornamental pieces. The ornamental detailing is varied throughout the palace. Calligraphic writing covers large portions of the palace as well as geometric patterning and patterns derived from nature. The artists of the Alhambra worked to create mosaic walls where the patterns create wall coverings with no central focus. Color was also widely used throughout the work, but it can now only be seen in certain areas.
Alhambra Palace - Court of the Lions 27
Formal Influences: Oscar Niemeyer
Oscar Niemeyer designs with curves in all aspects of his buildings.
Here he describes the influence of nature and curvature through his own work: â€œI am not attracted to straight angles or to the straight line, hard and inflexible, created by man. I am attracted to free-flowing, sensual curves. The curves that I find in the mountains of my country, in the sinuous course of its rivers, in the waves of the ocean, and on the body of the beloved woman. Curves make up the entire Universeâ€?.
Formal Influences: Toshiko Takaezu
The work of Toshiko Takaezu is influencing the outcome of the
research because on the sensual qualities represented in the work. This quote accompanied the piece, Torso at the Seattle Art Museum: “Japanese - American Toshiko Takaezu was a leading artist in the U.S. who envisioned organic, often figurative shapes, and earth-worn surfaces as sculpture - thereby resisting convention in a move beyond functional ceramic pots and bowls. In her handling of clay, she expresses a poetic sensibility and sensuality through material. Of her practice, the New York Times wrote: “Takaezu blended the expressive bravura of painters like Jackson Pollock and Franz Kline with the calm, meditative quality of traditional Japanese pottery...””
Torso, 2000 29
Two options for the construction assembly of the columns are
considered. The first system creates panels out of the terra cotta which requires a structural core with an attachment system. One column is composed of approximately 16 panels, and this varies depending on the geometry of each column. The final number of panels per column is determined based on the constraints of the molds. All molds are routed on the 3-axis CNC machine, therefore the limitations of the machine need to be taken into consideration when dividing the column. If a column design has an area with undercuts, that area will need to be divided in such a way that the mold can be produced on the machine, but assembled with the desired outcome.
The structural core of these columns is an independent system
which needs to respond to the undulating form of the panels. Each panel has clips which are attached to the back of the panels. These clips are made out of terra cotta and attached to the panel with a slurry mixture. Slurry is very wet clay which fills the gaps of the two pieces coming together. Each piece has been scored to increase its surface area to create a strong bond. These clips allow the panels to be held from behind without revealing the clamping mechanism that holds the panels to the structural core. The structural core is made from plywood which also is cut on the CNC router. In order for the core to precisely hold the panels, the design of the plywood needs to take into consideration the amount of shrinkage that the panels experience through drying and firing. Between the time when the panels are cast and fired, the panels shrink about ten percent.
The other column system results in a series of large hollow bricks
which are stacked one on top of another. In this system, the terra cotta is molded into a continuous shell that is one foot in height. Each column is divided into eight bricks. The thickness of the walls in the bottom bricks needs to be increased in order to withstand the weight of the upper bricks. When designing the molds for the bricks, a similar process as for the panels is used. The molds are still be routed on the 3 axis CNC router, therefore they require particular attention to how the molds will be split apart and later reassembled to create one hollow mold. These molds will be held together with clamps while the terra cotta is being pressed into them. Once the terra cotta begins to dry and is hard enough to maintain its shape, the molds will be released. Brick method
Both panel and brick
systems require an understanding of the overall center of mass. In order for each system to stand, the center of mass needs to be placed strategically. The overall form can increase the structural stability of the columns. For example, when columns are placed next to one another and form a larger column their center of mass is in a better location, compared to certain designs of a single column as the final form. When combining columns, new spaces can be created and the center of the column can be inhabited. The overall form of the columns would give the structural stability and individual columns can depend on the neighboring column for support.
Single column versus column grouping
During the process of making the terra cotta panels and bricks,
the potential for cracking in the terra cotta develops while it is drying. It is especially important for the bricks to be placed on a material which can move along with the terra cotta so not to create unnecessary strain on it which would result in cracking. Newspaper provides such a surface to allow for the terra cotta to move easily. When the terra cotta is dry and ready for firing, the temperature of the kiln will determine the outcome of the final color. The warmer the kiln, the darker the final product will be. After the terra cotta is fired once, glazes can be applied to create color effects. Multiple color glazes can be used on a single piece, but caution needs to be taken when applying them to be conscious of the bleeding that will occur. Glazes will turn into a liquid in the kiln and bleed into one another, resulting in effects that cannot be entirely controlled. The application of these glazes is optional and vitrification of the terra cotta is reached during its first firing.
Technical Precedent: Mario Botta
The Bechtler Museum of Modern Art in Charlotte, North Carolina
was designed by Mario Botta and clad in a terra cotta rain screen system. The concept of the building involved cutting voids out of a solid block of clay, resulting in a sculptural form which required a cladding system that could respond to the unique geometric qualities of the building.1 Terra cotta provides great freedom in the sizing of the panels, allowing small segments to contour to the buildings unique facade. In a rain screen system, the terra cotta panels are attached with clips to a structural steel frame, typically attached to a CMU wall construction. A layer of insulation, waterproofing and an air gap separate the CMU block from the terra cotta panels. In recent architecture, use of terra cotta is mainly found in the panel form, but terra cotta also has structural properties. When a terra cotta shell includes interior webbing, it becomes a brick which has enough compressive strength to stack a building up to three stories high. Because of it’s limiting height, it is rarely used as a structural element, but widely used as a cladding system which allows great diversity in its wide range of color options and ability to cover varying types of forms. 1. “The Bechtler Museum of Modern Art”. Boston Valley Terra Cotta. http://www.bostonvalley. com/project-portfolio/feature-project.html. 2012, Feb. 21.
(right): The BIO SKIN ed by traditional sudare, s or blinds used to shade ings from light and heat.
Technical Precedent: Bio Skin
The Nikken Sekkei Research Institute developed a cooling facade
system for the Sony Research and Development Center in Tokyo. Tokyo experiences severe heat island effects and the goal of the facade was to reduce the building’s impact on its surrounding environment. The facade is assembled out of terra cotta louvers which carry water through their cores. The terra cotta used in this system is specifically chosen for its porosity to allow water to move from its core into the surrounding environment. This system has a “high evaporative cooling capacity, alongside ordinary sample louvres made of aluminium”1 and has the ability to cool the building by two degrees.
1. John Wiley & Sons Ltd. “Bio Skin Urban Cooling Facade”. Architectural Design.
opposite top and right: The screen-like design of BIO SKIN allows views out across the city.
Technical Precedent: Mario Occhiuto
Mario Occhiuto designed the B2 and C1 buildings for the Shanghai
2010 World Expo. The project worked with three existing shed buildings and developed a new facade. The design maintains the structure and overall form of the sheds but gives them a new life with the renovated shell. The facade is constructed out of terra cotta panels which vary in their perforations, allowing light into the building during the day, and lighting up as a beacon in the evening.
Technical Precedent: Ecooler
Mey and Boaz Kahn from Israel designed the â€œecoolerâ€? screen
which won an IIDA award in 2010. Their design is influenced by traditional decorative screens, but incorporates a new strategy to provide additional cooling to the space. The screens are made using a slip cast method in a plaster mold, creating a hollow cavity between the two halves. Cool water flows through the assembly, and cools the surrounding environment. Mey and Boaz Kahn have designed a screen which is both visually appealing, relates to the history of their culture and is functional.
The columns formal design takes on the qualities of the sensual
human body. The female form was specifically looked at for the natural curves and movement within a figure. There are no hard edges and the detailing emphasizes the appearance of the column being in a continuous state of motion. The original making of terra cotta roof tiles also inspired the forms of the individual panels. Roof tiles were molded over the builderâ€™s leg to get the same approximate size and curvature in each of the tiles. The column brings together the formal aspects of the human body as well as its origins of how the body influenced its making.
Sketch by Aomori 39
Design: Multiple Columns
Throughout the design process, the tool was always playing a key
role in the design. The 3-axis router was the main fabrication tool in the production of the molds to cast the terra cotta pieces into. The tool itself created a set of limitations on the project. First, the 3-axis router cannot rotate, therefore any panels which have an undercut needed to be split apart into smaller segments. Also, the machine has maximum height restrictions for the material that it is cutting into. The material and the bit length cannot exceed the maximum retraction height of the machine. So if a panel exceeded 5 inches in depth, the mold would need to be split into smaller segments.
Tool Length Machine Limitation
Maximum material thickness
The human hand and the ceramics tools that were used to form the
final panels also played a key role in the design process. Panels that had tight curves were difficult to form because hands and tools were unable to access these areas. Therefore, panels had curvature limitations and were designed so they could be properly formed using these tools.
= 3-Axis limitations
Clay tool and hand limitations 43
Specific tool paths that the router would use to cut the molds were
designed for the entire column. All of the tool paths were drawn in order to create effects throughout the overall form. Depending on the width of a section, the tool paths will either be evident and create a texture, or create a completely smooth surface. These tool paths also follow the shape of the panels rather than running parallel to one another, creating a vertical movement in the overall form.
Once the individual panels are designed with their tool paths, each
panel is looked at for its overall depth and for any areas where there would be collision problems with the 3-axis CNC router. Panels with a depth greater than four inches were split into two pieces along one of the tool paths. The tool path provided a clean location to have a joint in the mold because it
would blend into the neighboring tool paths rather than cutting multiple tool paths in half. Panels that had potential collision problems were also split in half so the final surface was easily accessed by the machine. Once this was done, the panels were organized based on their depth and laid out on the stock in the most material efficient way possible.
The process for creating a single terra cotta panel extends over
the course of approximately two weeks. To begin, a mold is created to cast plaster into. The plaster cast must be larger than the designed mold to provide material for the CNC router to cut into. The depth of the mold is limited to six inches due to the restrictions of the CNC router. The mold also requires approximately a half inch or more plaster be left at the bottom to retain its strength while pressing the terra cotta. Depending on the overall size of the mold, this depth may need to be increased. Also, the maximum width and height dimensions of the mold are restricted to one foot by two feet. These limits are set based on the portability of the panels. Once they become larger than this size, they become difficult to move and assemble. Also, the plaster molds themselves would weigh over fifty pounds, and their weight would create additional logistical problems. The mold to cast the plaster is made out of Medium Density Fiberboard to build the sides and hardboard for the base. The hardboard provides a smooth surface which the plaster releases from easily. Angle brackets are used to hold the MDF together, and they make the mold easy to disassemble and use again for another cast.
The plaster is mixed at a ratio of seven parts water to ten parts
plaster powder. The plaster begins to set quickly and will be relatively solid after 25 minutes. Depending on the temperature of the water, the amount of stirring, and plaster to water ratio, this time can either be extended or shortened. Once the plaster is mixed, it is poured into the molds immediately, creating a uniform and smooth mold throughout. The drying time for the plaster varies on the thickness of the cast and humidity of the room where
it is being stored. It will feel cool to the touch until it is completely cured, meaning that there is no remaining water.
Four days after the plaster cast is poured, it can be routed on the
CNC mill. At this point, the plaster is still in a green state, meaning that water is still in the plaster and the mold is softer than it will be once completely dry. Routing takes place at this point to reduce the amount of dust created, but it is solid enough to retain the detail cut into the plaster.
Once the plaster molds reach room temperature, they are ready
to be used to cast terra cotta. These panels use a press-molding method. Another option would be to slip cast the forms, but this method has been avoided because it does not provide the strength needed in the panels. A slip cast would result in a much more delicate panel, and these panels require that they withstand their own weight as well as potential weight from stacking pieces.
Another option for creating a mold is routing plywood, medium
density fiberboard (MDF) or rigid insulation. Since the panels use a pressmolding technique, the material does not need to absorb water like in a slip cast. Slip casts require plaster molds so water can be absorbed into the plaster to create the thickness of the panel. Press-molding does not have as much water to be absorbed and the thickness is not determined by the absorption of the water. When using materials other than plaster, there is the possibility that they will not last as long. Plaster molds can be used approximately 100 times before they begin to lose their resolution. For the purposes of the final construction, these materials will be adequate in providing the necessary resolution since there will be a small number of casts made from each mold. The greatest benefit in using these materials is time. Plywood, MDF and rigid insulation can be cut down to the desired dimensions of the mold and laminated to create the needed depth. The following day, the molds can be cut on the CNC router and immediately used to cast the terra cotta using the press-molding method. The mold preparation of these other materials will take two days, compared to the seven required to prepare the plaster molds.
The terra cotta is rolled out on a flat surface to achieve a uniform
thickness throughout. Wooden dowels are used to limit the depth of the terra cotta. It is then lifted off of the surface and the smooth side of the terra cotta is hand pressed into the mold to create the front of the panel. The excess material is trimmed away and will be used for the next panel. The back of the panel is worked to remove the finger marks from pressing the clay into the mold. The panels dry in the molds for at least a day so they retain their
form. Once partially dry, they can be handled and any additional finish work can be done.
The panels will turn a light chalky red color once dried. A terra
sigillata mixture is applied to give the panels a deep red color once fired. Terra sigillata is terra cotta which has been mixed with water and pulverized. This mixture separates into three parts; water, a smooth middle mixture, and a heavy mixture which settles to the bottom. Terra sigillata is the smooth middle part and is applied before the first firing of the panels. The panels are then bisque fired, and result in panels that are approximately 10% smaller than the original casting.
After the bisque firing, the panels can be glazed. Several options
were explored, and two glazes have been chosen for the final column. An amber glaze gives the column a deep color, while a clear glaze brings out the natural color of the terra cotta while providing a glassy finish. Three layers of glaze are applied and the panels are placed into the kiln for their final firing.
Each firing takes about two days from the moment the kiln is started
to the time when they have cooled enough to be handled. Once the panels are removed from the kiln, they are ready to be assembled.
Procedure: Timeline Day 1
Day 1 - 4
plaster sets but is still cool to the touch
96 hours after pouring plaster
72 hours after routing plaster
Day 7 - 12
terra cotta dries - drying time varries depending on temperature, humidity and thickness of panel
Day 11 - 12
panels are fired in kiln and cooled
Procedure: Individual Panel Making
The clay is rolled out to a size large enough to lay into the mold
Clay is placed into the mold
Edges are trimmed using the edge of the mold and smoothed
Clay is pressed into the mold
Edges are roughly trimmed
Tabs and anchors are attached
Tabs and anchors are smoothed into the surface
The column was designed in 4 ring segments. Each ring is held
together in tension, and the segments were designed for the next ring to snuggly sit into the ring below. Each panel has four clips built into the back so it can securely be attached to the adjacent panel with wire that is looped between the clips. Once all of the panels in one ring are attached to one another, they create a continuous ring. With this method, each panel is necessary for the entire column to be assembled.
Ring Assembly with Clips
Ring Assembly Top View 58
Final Column Assembly 59
Epicurean Cast Sonia Tereszczenko