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Aluminum Finishes
in Postwar
Thomas C. Jester
Understanding the
evolution and range
of aluminum finishes
is critical to making
treatment decisions.
Fig. 1. Himco Storefront
Construction, cover and
rolled mouldings, published
by Himmel Brothers, 1946.
Courtesy of the APT Building
Technology Heritage
If and when colored aluminum becomes a permanent
thing, I think it opens up a great many fields simply
because the materials we have on hand really do not
give us the palette we need to cover today’s needs.
—Minoru Yamasaki, Aluminum in Modern Architecture, 1958
The twentieth century witnessed an explosion of new materials and assemblies
for construction. Avant-garde architects who subscribed to the tenets of Modernism embraced reinforced concrete and glass to create remarkable new buildings. If concrete and glass were the first two critical material legs of the stool for
Modern architecture, metals were the important third leg. The material qualities
of building facades, in particular, relied heavily on metals as the relationship
­between structure and skin evolved in the period after World War II.1­
Industrial materials and assemblies with
a wide array of finishes and standard,
known properties became the designer’s
palette.2 Architects in the Modern era
selected metals with finishes that produced a wide range of patterns, textures, and colors. Metals were selected
not only because they met specific performance criteria and characteristics but
also because they conveyed newness,
celebrated industrialization, and even
highlighted their specific qualities for
poetic effect.3
The development to Modern architecture was made possible, in part, through
the substitution of lightweight for heavy
materials, and the use of metals was
one of the keys that made the changes
possible.4 In 1947 the frontispiece to
the Architectural Metal Handbook,
published by the National Association
of Ornamental Metal Manufacturers,
declared, “Freedom of expression is the
cornerstone of progress in architecture.
The metals of old, supplemented by the
alloys of today, provide the strength,
utility and permanence, dignity and
beauty to make possible that freedom.”5
This statement signaled acceptance of
the growing impact of aluminum alloys in the building industry by Modern
architects in place of more traditional
metals, such as bronzes and nickel
silver, which had been used widely
through the 1930s.6 Other modern metals, like Monel, were more expensive
and used more commonly for applications like roofing.7 Lightweight metals
saved time, space, and weight. Architect
Eero Saarinen observed that “from the
miraculous potentials of engineering
and science will come new materials,
new possibilities and new problems.
These will have to be absorbed.”8 This
was particularly true for aluminum.
Throughout the late 1920s and 1930s,
architects used a variety of white “silvery” alloys, including aluminum,
stainless steel, nickel silver, Benedict
metal, zinc, and Monel, for decorative
elements in buildings.9 A wide range of
colors and textures could be achieved
with minor adjustments to the composition of the metals and mechanical manipulation of the metal surface
with buffing, brushing, and blasting.10
Fig. 2. Alcoa Aluminum Handbook,
published by the Aluminum
Company of America, 1957. This
manual featured Alcoa’s available
alloys that met commercial
standards and designations set by
the Aluminum Association.
William Van Alen, the architect of the
Chrysler Building in Manhattan, was
an early adopter of stainless steel. He
prized the permanence of the bright
finish, which he felt was important to
accentuate the lines of the building and
achieve a finish that constantly changed
in various light conditions.11
Doors, door hardware, letter boxes, divider strips in terrazzo, and grilles were
among the many uses of white metals
during the 1930s to achieve decorative
effects on the interiors and exteriors
of buildings. Aluminum could be cast,
forged, and extruded to create countless
types of architectural elements. Aluminum’s ascendency was swift, as the
material became more affordable. By
the late 1930s the Aluminum Company
of American (Alcoa) was producing
residential and commercial aluminum
windows, which began competing with
wood and steel windows and rapidly
eclipsed them. Alcoa’s 1938 product
literature stated, “Natural aluminum is
striking in appearance yet neutral in effect.”12
Storefront construction also witnessed
significant changes as a result of advances in metals. In 1906 Francis Plym
obtained a patent for a metal storefront
and soon after founded the Kawneer
Company in Kansas City, Missouri.
Early storefront systems made with
solid copper gave way to aluminum,
and by 1937 it was estimated that
75 percent of Kawneer’s product line
was aluminum.13 The Himmel Brothers Company’s 1946 catalog, entitled
Himco Storefront Construction, included “Modern Metals for Glass Settings,” which featured “Bronze and Alumilited Aluminum” in extruded shapes
and “Stainless Non-Magnetic Steel 188, Bronze, Alumilited (anodized) Aluminum, and Stainless Laminated Metal
(Pat.)” in cold-rolled products (Fig. 1).14
Aluminum’s hegemony would continue
to the point that Kawneer’s 1960 storefront catalog included only aluminum
products with the following finish
specification: “All exposed portions of
aluminum storefront moldings shall be
buffed to a mirror-like finish…and shall
be given an anodic oxide treatment in
accordance with Alcoa Specification
‘Alumilite 204 A1 R1.’”15
The rapid proliferation of aluminum
building products accelerated in the
postwar period, partly due to cost but
also because of the shift to the growing number of alloys marketed annually (Fig. 2). By 1954 manufacturers
adopted standard designations created
by the Aluminum Association for the
voluminous number of wrought alloys.16 The new Aluminum Association
designations permitted new alloys to
be assigned a unique designation once
accepted as a standardized metal with
known properties.
Experimentation and
Postwar Expansion
Architects frequently experimented with
metal materials. One of the most striking early examples of aluminum used
for a Modernist design was the Aluminaire House, designed by Lawrence
Kocher and Albert Frey. Constructed in
1931 for the Allied Arts and Building
Products Exposition in New York City,
the building was partially subsidized by
Alcoa, which provided the aluminum
components, including the corrugated
panels. At the Century of Progress International Exposition in Chicago in
1933, two houses looked to the future
with metals. The House of Tomorrow
featured metal siding, and the ArmcoFerro House was clad with 13-inchwide porcelain-enamel panels attached
with battens. During World War II,
Vultee Aircraft hired Henry Dreyfuss
and Edward Larrabee Barnes to design prefabricated metal housing using
18-foot-long-by-8-foot-tall aluminum
sheets bonded to a cellular core, but the
prototypes were never mass produced.17
Buckminster Fuller’s Dymaxion House
was noteworthy for its experimentation
with lightweight aluminum alloys that
had high strength-to-weight ratios.18
Although the projected mass production
never occurred, Fuller’s prototypes —
designed between 1941 and 1946 and
built in 1947 — reflected the passion of
its innovative designer.
Following World War II, the largest aluminum producers — Alcoa, Reynolds,
and Kaiser — pursued new markets to
absorb their increased wartime-production capacity, and the building industry
was targeted with aggressive marketing
through publications, demonstration
houses, and award programs.19 The
widespread availability of aluminum
in the late 1940s and early 1950s also
coincided with the rapid arrival of another important building assembly: the
curtain wall. Pietro Belluschi’s Equitable
Savings and Loan Building in Portland,
Oregon, constructed in 1948, featured
prefabricated cast- and sheet-aluminum
panels in a contrasting configuration
to emphasize the reinforced-concrete
structure.20 In 1949 French architect
Jean Prouvé, a staunch supporter of
industrial construction methods and
new materials, incorporated large, prefabricated aluminum panels to form
the curtain wall for the Building Trades
Federation headquarters in Paris.21
On a larger scale, the 30-story Alcoa
Building in Pittsburgh, Pennsylvania,
designed by Harrison and Abramovitz
and completed in 1953, was widely
publicized as a “daring expression of
the metal curtain wall.”22 In contrast
to the mostly-glass curtain wall of
the early 1950s, the Alcoa Building’s
curtain wall, a so-called “Aluminum
Dress,” was formed with large 6-footby-12-foot stamped anodized panels of
“iridescent gray color” (Fig. 3).23 Aluminum windows with rubber gaskets pivoted to allow cleaning from within the
building. Alcoa’s promotional materials
pointed out that “if the Alcoa Building
had used conventional construction,
it would have weighed in at an additional 10,340 tons!”24 In the late 1950s
aluminum curtain walls increasingly
featured stamped “machine ornament,”
a prominent example of which was 666
Fifth Avenue in New York City, which
at the time of completion in 1957 was
Fig. 3. Alcoa Building, curtain-wall
detail, Aluminum on the Skyline,
published by the Aluminum
Company of America, c. 1954.
the largest aluminum curtain wall ever
built (Fig. 4).25 Later, more expressive
uses of aluminum as “skin” to deemphasize the structural frame would be
found in works like Cesar Pelli’s 1968
design (while at Daniel, Mann, Johnson,
Medenhall) of the Comsat Laboratory
Building in Clarksburg, Maryland (Fig.
5). Joint widths were minimized to allow the clear anodized aluminum to
­appear as a wrapper, conveying a tautness and lightness to the structure.26
tion would grow rapidly in the postwar
period, particularly for curtain-wall assemblies.29 The curtain-wall assembly
for General Motors Technical Center
in Warren, Michigan, designed by Eero
Saarinen in 1950, was a 2-inch-thick
composite panel of porcelain enamel on
aluminum, laminated to a paper honeycomb core.30 Other core materials used
for honeycomb composite panels in the
postwar period included aluminum,
stainless steel, fiberboard, and plasticimpregnated glass.31
Fig. 4. Tishman Building, 666 Fifth
Avenue, New York, New York,
1957, designed by Carson and
Lundin. Detail of aluminum and
porcelain enamel curtain wall.
Photograph by the author.
Fig. 5. Comsat Building,
Gaithersburg, Maryland, 1968.
Photograph by the author, 2015.
Metals also were often used in the
growing number of composite materials that took advantage of the properties of more than one material to make
lighter, stronger materials. In 1947 Steel
magazine would declare that “composite material is the Janus of many of
today’s cleverly engineered lighter structures.”27 One of the early composite
materials using metal was the Haskelite
Manufacturing Company’s Plymetyl.
Light-gauge metals — zinc-coated steel,
aluminum, Monel, stainless steel, and
porcelain enamel — were bonded with
phenolic resin to plywood or insulating
board.28 Composite sandwich construc44
In 1940 Buffalo-based Rigidized Metal
Company introduced deep-textured
sheet metals for architectural applications in both ferrous and non-ferrous
metals, including aluminum. Formed by
rolling, the embossed Rigid-Tex sheets
came in a wide range of patterns and
varying pattern depths (Fig. 6). Promoted for its increased tensile strength
and elimination of any distorted surface
reflections (oil canning), the products
gained widespread acceptance in exterior and interior uses, ranging from
curtain-wall panels to elevator cabs.32
The growing popularity of textured
aluminum during the 1950s spawned
competitors. The Aluminum Company
of Canada (Alcan), for example, offered
embossed aluminum sheets and coil in a
variety of gauges and patterns. Alcan’s
1956 promotional catalog noted that
its sheet could be painted or lacquered,
in addition to the natural finish it offered.33
Postwar Aluminum Uses
and Finishes
Stainless steel and aluminum dominated
as the metals of choice for architects
during and after World War II and into
the early 1950s. As the number of finishes for stainless steel and aluminum
grew, they provided architects with
more choices than ever before. For Mies
van der Rohe, materials were to be
used for structure or enclosure, and he
believed materials should be used based
on research and facts. He commented in
1956 that “the danger with aluminum
is that you can do with it what you
like; that it has no real limitations.”34
But Mies’ warnings would not stop the
major three aluminum producers from
flooding the market with an ever-growing array of aluminum components, including windows, doors, siding, roofing,
storefronts, curtain walls, sun-control
devices, flashing, railings, copings, and
acoustical ceiling assemblies, not to
mention structural components. Aluminum quickly became ubiquitous in
buildings, partly because it had become
economical but also because of the aluminum industry’s marketing prowess.
Types of Aluminum Finish
Finishes for aluminum fall into three
categories: mechanical, inorganic, and
organic.35 Typical mechanical finishes,
achieved with brushes or abrasives to
impart texture and contrast, ranged
from satin, sandburnished, polished,
sandblasted, and spin finished to
frosted. Inorganic finishes on aluminum
could be created with chemicals, chemical oxidation, electrochemical treatment
(anodizing), electroplating (metal fused
to aluminum), and porcelain enamel
(glass fused to aluminum).36 Organic
finishes include synthetic lacquers, alkyd
methacrylate lacquers, and paint.
Anodizing, prized for its corrosion resistance and ability to maintain its original
appearance over time, would prove to
be the most important aluminum finish.
Anodizing was first used on British Duraluminum for sea-plane parts in 1923
based on the patented Bengough-Stuart
process. A process using sulfuric acid
was patented by Gower and O’Brien in
1927, and the Japanese introduced an
anodizing process with oxalic acid in
1923 that was widely used for architectural applications in Germany.37 Alcoa
first patented its color-anodizing process
in 1923 and by 1928 was commercially
producing anodized aluminum under its
Alumilite trade name.38
Advances in processes and techniques
for anodizing aluminum played an important part in its widespread use in
buildings. The anodizing process created a thin, protective film of aluminum
oxide that could be clear or colored.
According to the Reynolds Metal Company,
The result is a uniform, hard glass-like film that
is not on top of the metal but an integral part
of the metal surface itself. Its thickness will be
from 0.0008 to 0.0010-inch, according to the
processing. Its appearance will vary from that
of a clear, perfectly transparent coating, to a
dark, opaque, slate gray….This film not only
offers great resistance to abrasion and corrosion
but also provides amazingly effective protection
against weathering.39
In 1938 Alcoa noted in its product
literature that its Alumilite finish was
“proving useful for architectural parts
such as storefronts which must resist
atmospheric attack for prolonged periods, and still present a pleasing white
appearance.”40 Architectural applications in the immediate postwar period
typically used Alumilite No. 204 for
wrought products and Alumilite No.
704 for castings.41
Reflecting the fact that anodized aluminum remained somewhat of a novelty
well into the 1950s, the Reynolds Metal
Company devoted an entire section of
its 1958 supplement to Aluminum in
Modern Architecture to the benefits of
anodizing. It declared:
Not only did aluminum offer the benefit of its
strength-to-weight ratio: it had other possibilities that would interest architects, including
Postwar Metals and
The prolific use of white metals in the
1930s gave way to the growing use
of stainless steel and aluminum in the
1940s by architects as Modernism took
hold in the United States. Color was
often associated with ornament, and the
immediate postwar period relied largely
on a palette of materials with “natural”
color (in contrast to those deemed artificial). High-style Modernists favored
“a somewhat elastic range of materials:
travertine, marble, wood, leather, glass,
steel, and aluminum, each in their variety of finishes.”43 Louis Kahn’s use of
mill-finished stainless steel on the Yale
Center for British Art in New Haven,
Connecticut, in 1969 was one example
of a muted visual effect that embraced
the natural characteristics of a metal
finish (Fig. 7). Kahn’s deep interest in
the character and nature of materials
led him to the “pewter-colored” patina
on the British Center’s metal cladding.
Kahn described his vision for the appearance by stating, “On a cloudy day
it would look like a moth, on a sunny it
would look like butterfly.44
Interest in color grew as Modern architecture morphed away from the
perceived monotony of the glass-andmetal boxes of the immediate postwar
period and as Modernism became more
mainstreamed for the masses. Taking
into account the inherently disruptive
and transformative nature of scientific
advances that led to new materials,
manufacturers sought to expand their
reach in the architectural market by
offering new metal products with a variety of textures, patterns, and colors.
Architect Victor Gruen argued in 1958
that “if applied with judgment, taste,
and imagination, colored aluminum
opens tremendous new possibilities in
liberating our urban environment from
the dreariness created by the exclusive
use of the somber, ‘safe’ colors,’” which
he considered to be black, white, and
Throughout the 1950s interest in
color expanded, and manufacturers responded to give architects more choices
when designing with metals. In 1957
Alcoa’s newly created Residential Building Products Division hired Modernist
architect Charles Goodman to design
its “Care-Free” home (Fig. 8). The constructed houses, numbering fewer than
50 nationwide, featured color-anodized
aluminum (purple for the siding and
blue for the window grilles) and were
advertisements for how aluminum
could be used in residential construction. Aluminum elements in the house
included the roof, fascia, lighting, diffusers, hardware, outlet covers, and
even termite shields.46 This program reflected not only the desire of aluminum
manufacturers to expand their reach
into the residential marketplace but also
the growing shift toward acceptance of
color in Modern architecture, as fashions changed and shifted away from
the natural colors supported by firstgeneration, high-style promulgators of
Modernism to brighter possibilities.
Porcelain enamel on aluminum.
Boosters of porcelain enamel, a vitreous enamel of glass fused to metal
(originally on enameling iron), were
Fig. 6. Pattern selector for
Rigidized Metals Corporation,
c. 1950s. The company is
celebrating its 75th anniversary
in 2015. Courtesy of Rigidized
Metals Corporation.
Fig. 7. Yale Center for British Art,
New Haven, Connecticut, 1969.
Photograph by Richard Caspole,
Yale Center for British Art.
convinced that the material was poised
for growth in the building industry, proclaiming in 1938 that porcelain enamel
would take over as “the Favorite Finish
of the Future.”47 Initially used for gas
stations and storefronts in muted and
mottled colors, porcelain enamel gained
traction in curtain-wall systems in the
1950s. Architects selected it for its longlasting, nearly permanent color and
strong resistance to corrosion and atmospheric weathering. Porcelain enamel
was offered in a wide range of color
choices, and the base metal could be
roll-embossed prior to enameling to create textured finishes. Gloss, semi-gloss,
process to seal UV-stable coloring media in the oxide film of the metal at the
end of the anodizing process. Sealing
typically involved placing the metals in
boiling water to close the pores (by converting the lining of the pore walls into
monohydrate form).55 Color-anodized
parts were typically sealed twice: first
in “hot solutions of nickel or cobaltous
acetates” to hold the dyes in the oxide
film and prevent leaching and, finally,
in boiling water. Corrosion inhibitors
could be added when maximum corrosion resistance was desired.56 Additional
protection was afforded by the application of a coating of clear lacquer baked
on the anodized metal.
Fig. 8. Cover of Alcoa Care-Free
Home, published by the Aluminum
Company of America, c. 1958.
The exterior featured anodizedaluminum components, including
purple siding panels and iridescent
blue lattice work in front of the floorto-ceiling windows.
and matte finishes permitted control of
One advantage of porcelain enamel was
that bright colors could be achieved
due to improved opacity, enabling thinner enamel coatings on the base metal.
By the mid-1950s overall enamel-coat
thicknesses on steel averaged between
0.006 and 0.014 inches and could be as
high as 0.025 inches.48 In 1950 Kawneer pioneered a process for applying a
low-temperature porcelain enamel on
aluminum, which was sold under the
trade name Zourite.49 The aluminum
base allowed the enamel coats to be
reduced significantly, to between 0.006
and 0.013 inches.50 One of the most innovative and technologically advanced
applications was Eero Saarinen’s vivid,
two-toned blue curtain wall at the IBM
Research Center in Rochester, Minnesota, dating to 1956-1958 (Fig. 9).
The spandrels had an asbestos-cement
core and were just 5/16 inches thick. The
building was described as having the
“world’s thinnest wall.”51
Color-anodizing technology. Until the
early 1950s the only colors available
for exterior applications of anodized
aluminum were transparent finishes and
variations of silver. Black, grey, and
green colors could be achieved with
chemical conversion processes, such as
chromatizing and phosphatizing, which
were most commonly used as a primer
for painted finishes.52 Polished finishes
on aluminum could be achieved with
chemical polishing. While some colors
of anodized aluminum could be specified safely for interior use, colors for
exterior use were limited, due to the UV
degradation of some color media over
time with exposure to sunlight. The UV
stability depended upon the stability of
the coloring media, the concentration in
the oxide layer, and the depth of penetration.53 Despite the limitations in durability, the Reynolds Metal Company
recognized the potential of color, noting
that “the metallic luster of colored anodic films has great decorative attraction,” and devoted considerable energy
after World War II to improving various
methods for color dyeing anodized aluminum.54 By the late 1950s manufacturers were beginning to produce a wider
color range for anodized aluminum,
and they continued to experiment with
materials and processes that might lead
to commercially viable anodized finishes with an even wider range of colors
while maintaining the benefits of the
protective oxide layer afforded by the
electrochemical finishing process.
A wider range of colors became available only with improvements in the
Anodic films could be colored in one
of three ways. Organic, water-soluble
dyestuffs and inorganic pigments were
used to create various colors.57 In this
method, anodized components were
dipped directly into a dye bath and
absorbed the color. Colors could also
be created by treating the natural oxide
film with solutions that formed inorganic colored compounds. This method
could create black and blue colors. In
a third method, film in such colors as
silvers and browns could be achieved
directly in the anodizing bath with the
addition of acids and other agents. Variations in the alloys also influenced the
color of the anodic coating. Chromium,
for example, produced a yellowish tint,
and manganese created brown hues.
Finally, manipulation of the metal with
mechanical and chemical treatments
prior to anodizing also created varying
color shades and the potential for contrast. Rougher surfaces tended to appear
darker after application of the Alumilite
finish, making color matching of different anodized elements difficult.58
By 1956 colors suitable for exterior use
included blue, yellow, black, and gold,
in addition to the clear (transparent)
and gray finishes. Architect Minoru
Yamasaki embraced the potential of
colored aluminum, stating, “Anything
that increases our palette is wonderful,
and if and when colored aluminum becomes absolutely a permanent thing, I
think it opens up a great many fields.”59
His 1958 design for the Reynolds Great
Lakes Sales Region Headquarters Build-
ing in Southfield, Michigan, incorporated gold, silver, and black anodized
aluminum and was a widely published
billboard for the color-anodized aluminum (Fig. 10).
The rise of earth-toned anodized finishes. The wider use of colored metals
in the 1950s and early 1960s eventually
shifted to a more natural color palette
in late 1960s and 1970s. Earth-tone
colors on anodized aluminum replaced
brighter colors, and clear anodized
aluminum and stainless steel were used
with less frequency. As earth-toned
materials, such as cast-in-place and precast concrete, brick, and stone, gained
prominence during the second half of
the 1960s, champagne and light bronze
anodized finishes, as well as medium
bronze, dark bronze, and black anodized finishes, were used extensively to
compliment the more natural tones in
the cladding materials. This trend would
continue well into the 1970s.
Darker, earth-toned aluminum colors
also complimented buildings constructed with other metals used in the
late Modern period, including weathering steel and copper-based alloys,
such as bronzes, brasses, and Muntz
metal. Architects also used dark bronze
anodized elements, such as spandrel
panels, to contrast with lighter-colored
aluminum elements, like curtain-wall
mullions. Representative of this approach and the period is the Rohm and
Haas Building in Philadelphia, which
was designed by Pietro Belluschi and
completed in 1965.60 Belluschi, no
stranger to innovative uses of materials, wrapped the concrete building with
balconies that also served as sunshades
(Fig. 11). The sunshade latticework was
constructed with dark bronze anodized
aluminum and provided a frame for
corrugated Plexiglas panels in a bronze
The predominance of the earth-toned
colors of anodized aluminum may also
be explained by the evolution and maturation of anodizing technology. Colors
in the brown and bronze range could be
created using materials and techniques
that produced finishes with the greatest amount of resistance to UV-light
degradation in exterior applications.
Manufacturers continued to search for
improved manufacturing processes that
provided superior performance of coloranodized aluminum. Around 1985 electrolytically deposited anodic coatings
were introduced. This process is widely
used for exterior architectural applications requiring significant UV stability.
Producing colors in the light bronze to
black range, this process involves the
application of stable metal pigments
into the anodized-aluminum coating
through immersion in a bath of metal
salts subjected to an electrical current.61
In the quarter century after the conclusion of World War II, the number of
new aluminum metal alloys — and wide
range of finishes — witnessed tremendous growth in architectural applications. Architects, intrigued by the opportunities that new industrial materials
presented to achieve new forms, selected
from a wide range of metals and metal
finishes offered by manufacturers. At
the same time, standardization of aluminum alloys increased, as the need
Fig. 9. IBM Research Center, Rochester,
Minnesota, 1956-1958. Photograph by
Balthazar Korab, courtesy of the Library
of Congress.
for predictable performance grew and
technological advances occurred. Manufacturers also experimented with techniques to expand the uses and ranges
of finishes for architectural aluminum.
Today, as Modern-era buildings require
renewal with ever-growing frequency,
it is important to understand the range
and complexity of materials used. The
postwar period was one of rapid change
in the materials and metal finishes available, and the legacy of architectural
production is equally rich and varied.
For this reason, a strong understanding
of the alloys used and how the finishes
were created is essential when evaluating aluminum’s condition and in developing sensitive and appropriate repair
and conservation programs.
Fig. 10. Reynolds Metals Regional
Sales Center, Southfield,
Michigan, 1958. Photograph by
Balthazar Korab, courtesy of the
Library of Congress.
Thomas C. Jester, AIA, FAPT, LEED
AP, is a senior associate at Quinn
Evans Architects. He is the editor of
Twentieth-Century Building Materials:
History and Conservation, which
was recently reissued by the Getty
Conservation Institute. This paper is
based on his presentation at APT’s
Modern Metals Finishes Workshop
held in New York in 2013. He may be
reached at [email protected]
I am grateful to Robert Hotes, Todd Grover,
and Christian Korab for their assistance with
illustrations used in this article.
1. On the evolution of the relationship between
structure and skin, see David Leatherbarrow
and Moshen Mostafavi, Surface Architecture
(Cambridge: MIT Press, 2005), 80.
2. See D. Knickerbacker Boyd, “The
Standardization of Building Materials,”
Architectural Forum 31 (July 1919): 31-33.
On the impact of standards on the relationship
between builders and architects, see Moshen
Mastafavi and David Leatherbarrow, On
Weathering: The Life of Buildings in Time
(Cambridge: MIT Press, 1993), 20.
3. Mostafavi and Leatherbarrow, 120.
4. On the growth of aluminum as a lightweight
structural material and its properties, see
Aluminum Construction Manual (New York:
The Aluminum Association, 1959), 9.
5. Earl P. Baker and Harold S. Langland,
Architectural Metal Handbook (Washington,
D.C.: R. R. Donnelly and Sons, 1947), 34.
6. John Peter, Aluminum in Modern Architec­
ture, vol. 1 (Louisville: Reynolds Metal Co.,
1956), 9.
7. See, for example, Monel for Permanent
Roofs (New York: International Nickel Co.,
1938). Accessed from the APT Building
Technology Heritage Library, https://archive
8. Eero Saarinen, “Six Broad Currents of
Modern Architecture,” Architectural Forum
99 (July 1953): 115, as quoted in Eeva-Liisa
Pelkonen and Donald Albrecht, eds., Eero
Saarinen: Shaping the Future (New Haven:
Yale Univ. Press, 2006), 233.
9. See Ernest E. Thum, The Book of Stainless
Steels (Cleveland: The American Society for
Steel Treating, 1933), 555. In decreasing
order of cost, available white metals at the
time included Monel (67.5% nickel, 28.5%
copper); stainless steel (18% chromium, 8%
nickel); nickel silver (75% copper, 20% nickel,
5% zinc); Benedict metal (57% copper, 28%
zinc, 15% nickel); stainless irons and steels
(18% chromium and 12% chromium); and
10. Dennis Montagna, “Twentieth-Century
Ornamental Metals and Their Care,” in
Preserving the Recent Past Conference
Proceedings (Washington, D.C.: Historic
Preservation Education Foundation, 1995):
11. Thum, 556.
12. Windows of Alcoa Aluminum (Pittsburgh:
Aluminum Company of America, 1938).
13. Dennis Doordan, “From Precious to
Pervasive: Aluminum in Architecture,” in
Aluminum by Design, ed. Sarah Nichols
(Pittsburgh: Carnegie Museum of Art, 2000),
14. The stainless laminated metal product
was “non-tarnishable and made of Stainless
Steel 18-8 laminated over a noncorrosive base.
They present exactly the same appearance
as solid stainless at a fraction of the cost.”
Himco Storefront Construction (Hamden,
Conn.: Himmel Brothers, 1946), 2 and D1.
Accessed from the APT Building Technology
Heritage Library,
15. Aluminum Store Fronts, 1960 Catalog
(Niles, Mich.: Kawneer Company, 1959), 17.
Accessed from the APT Building Technology
Heritage Library,
16. Alcoa Aluminum Handbook (Pittsburgh:
Aluminum Company of America, 1957), 8.
The Aluminum Association’s aluminum alloy
designations created standard designations to
replace old designations issued by a litany of
other organizations, including ASTM, federal,
military, and the Society of Automotive Engi­
neers. See Aluminum in Modern Architecture,
vol. 2, 23.
17. See Peter S. Reed, “Enlisting Modernism,”
in World War 2 and the American Dream:
How Wartime Building Changed a Nation,
ed. Donald Albrecht (Cambridge: MIT Press,
1995), 29.
18. Aluminum by Design, 240. See also, James
Ashby, “Preserving a Prototype: Buckminster
Fuller’s Dymaxion House,” in Preserving
the Recent Past 2 Conference Proceedings
(Washington, D.C.: Historic Preservation
Education Foundation), 3-1-3-8.
19. Doordan, 104.
20. Robert L. Davison, “Thin, Lightweight
Curtain Walls,” Architectural Forum 92
(March 1950): 94-95. See also, Aluminum in
Modern Architecture, vol. 1, 24-25 and David
Thomas Yeomans, “The Arrival of the Curtain
Wall,” in Preserving the Recent Past 2, 3-140.
21. Aluminum by Design, 244. On Prouvé’s
tectonic impulses and experimentation with
aluminum, see Leatherbarrow and Mostafavi,
22. Aluminum in Modern Architecture, vol.
1, 136. Other early Harrison and Abramovitz
buildings with faceted aluminum curtain walls
include the Republic National Bank (1955)
in Dallas and the Socony-Vacuum Building
(1956) in New York.
23. Aluminum on the Skyline (Pittsburgh:
Aluminum Company of America, c. 1954), 9.
24. Ibid., 16.
25. Aluminum in Modern Architecture, ’60
(1960 Supplement) (Louisville: Reynolds Metal
Co., 1958), 27. See also, Thomas Mellins,
Robert A. M. Stern, and David Fishman, New
York 1960 (New York: The Monacelli Press),
26. For a detailed account of the Comsat
Headquarters design and its antecedents, see
Isabelle Gournay, “Comsat Headquarters
Maryland Historical Trust, Maryland
Inventory of Historic Properties Form,” Nov.
1, 2004.
27. “Composite Materials Attract Designers of
Lighter Structures,” Steel (June 9, 1947): 76.
28. Ibid., 78.
29. On the range of composite “sandwich”
construction used in mid-century curtain walls,
see The Contemporary Curtain Wall (New
York: F. W. Dodge Corporation, 1958), 309335.
30. Aluminum in Modern Architecture, vol. 1,
31. The Contemporary Curtain Wall, 317.
32. Robert Score and Irene J. Cohen, “Stainless
Steel,” in Twentieth-Century Building Ma­
terials, ed. Thomas C. Jester (New York:
McGraw Hill, 1995), 70.
33. Alcan Embossed Pattern Aluminum
Sheet (Montreal: The Aluminum Company
of Canada, 1956), 2. Accessed from the APT
Building Technology Heritage Library, https://
34. Aluminum in Modern Architecture, vol. 1,
35. In the late 1930s Alcoa’s categories for
finishes were mechanical, chemical, electro­lytic
oxide, electroplating, and paint/lacquer/
enamel. See Finishes for Aluminum (Pitts­
burgh: Aluminum Company of America,
1938). Today, finishes for aluminum in
archi­tectural applications are designated by
the National Association of Architectural
Metal Manufacturers as mechanical (M),
chemical (C), anodic (A), electroplated (E),
vitreous (V), organic (O), and laminated
(L). See Metal Finishes Manual (Chicago:
National Association of Architectural Metal
Manufacturers, 2006), I-18.
36. The Contemporary Curtain Wall, 127.
37. Chris Adams and David Hallam, “Finishes
on Aluminum — A Conservation Perspective,”
in Saving the Twentieth Century: The Conser­
vation of Modern Materials, ed. David Hallam
(Ottawa: Canadian Conservation Institute,
1993), 277.
38. Aluminum by Design, 256.
39. Aluminum in Modern Architecture, ’58
(1958 Supplement) (Louisville: Reynolds Metal
Co., 1958), 88.
40. Finishes for Aluminum, 37.
41. Architectural Metal Handbook, 22.
42. Aluminum in Modern Architecture, ’58,
43. William Braham, “The Authority of the
Natural: Color Palettes of the Postwar Period,
1948-1968,” in Preserving the Recent Past 2,
44. Peter Inskip and Stephen Gee, Louis I.
Kahn and the Yale Center for British Art: A
Conservation Plan (New Haven: Yale Univ.
Press, 2011), 72.
45. Aluminum in Modern Architecture, ’58,
46. See
.html (accessed Nov. 15, 2014).
47. J. E. Hanson, A Manual of Porcelain
Enameling (Cleveland: The Enamelist Pub­
lishing Co., 1937), 466.
48. The Contemporary Curtain Wall, 205.
49. “Kawneer Enamels Aluminum for Profit,”
Ceramic Industry 55 (Nov. 1950): 55-56.
50. The Contemporary Curtain Wall, 205.
51. Pelkonen and Albrecht, 50-51, 198.
52. The Contemporary Curtain Wall, 127.
53. Aluminum in Modern Architecture, ’58,
54. Aluminum in Modern Architecture, vol.
2, 73.
55. Aluminum in Modern Architecture, ’58,
56. Aluminum in Modern Architecture, vol. 2,
57. Ibid., 74. See also, Aluminum in Modern
Architecture, ’58, 94.
58. Finishes for Aluminum, 41.
59. Aluminum in Modern Architecture, ’58,
60. Rohm and Haas Corporate Headquarters,
National Register of Historic Places Nomina­
tion, 2006.
61. Metal Finishes Manual (Glen Ellyn, Ill.:
National Association of Metal Manufacturers
and National Ornamental and Miscellaneous
Metals Assoc., 2006), 1-9.
Fig. 11. Rohm and Haas Building,
Philadelphia, Pennsylvania, 1965.
Photograph by Robert Hotes, 2015.
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