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Thursday, May 30 • 3:00pm - 3:30pm
(Architecture) Bringing Modern Back: Restoring 1930’s Aluminum Finishes

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Helen M Thomas-Haney, Conservator, Jablonski Building Conservation; and Xsusha Flandro, Senior Architectural Conservator, Jablonski Building Conservation

“Peer into the Future…ALCOA Aluminum is revealed a shining symbol of strength... lightweight… enduring beauty”- 1931 ALCOA Advertisement

In the 1930s aluminum was hailed as the new wonder material capable of withstanding weathering and structural stresses. Aluminum was being used for a wide variety of materials including architectural features such as windows, spandrel panels and decorative elements. ALCOA advertisements claimed that “Rain, hail, and snow fight Alcoa Aluminum and lose.”

In 1932, stamped cast and extruded aluminum was used to create the spandrel arch at the 4th Avenue station in Brooklyn. 4th Avenue is an elevated station on the BMT line of the New York City Transit System. The arch stretches across a four-lane street and stands approximately 30’ tall. It is currently listed as a state historic landmark.

The restoration of the 1932 aluminum paneled spandrel arch proved that aluminum is not as weather resistant as originally advertized. The initial goal of the aluminum restoration was to remove over-paint from the aluminum and reapply finishes to match the original appearance in-situ. However, the lack information on aluminum restoration complicated the project. Years of poor maintenance, layers of paint, and inappropriate interventions lead to more deterioration than was anticipated.

The restoration started with a review of the original drawings, specifications, and photographs. The drawings noted that three different types of mechanical finishes were to be used on different elements of the façade – “satin,” “sand-blasted,” and “sand-blasted deplated.” Paint removal mock-ups as well as an examination of paint samples, confirmed that these finishes were indeed installed. However, corrosion and pitting of the aluminum surfaces beneath the paint required that the corrosion be removed prior to re-instating the finishes.

Little information on the restoration of architectural aluminum and aluminum finishes exists. Extensive research using digital archives as well as resources through AIC and APT were used to define satin and sand blasted finishes while deplated was not found in this search.

It was the discovery of an early trade book, “Aluminum in architecture” (1932), which contained descriptions of different types of aluminum finishes, including “deplated” that provided the key to understanding these finishes. Deplating was the result of a process requiring the entire aluminum panel to be dipped in an electrically charged solution.

Cleaning the corrosion from the aluminum in situ became a challenge. Since blasting was rejected on grounds of containment, another method had to be found. Working with the contractor, another mechanical method was found using a rotary machine that would simulate a coarse “blasting,” but without the resulting debris.

Although aluminum was advertized as being corrosion resistant, it does corrode. Coatings are required to prevent the reaction of the aluminum with the atmosphere. New coating materials were researched that would be easy to apply in the field and be compliant with VOC regulations.

When the aluminum spandrel arch was finally cleaned and refinished, it once again showed what ALCOA had advertised in the 1930’s, “Aluminum is revealed a shining symbol of strength... lightweight… enduring beauty.”


Xsusha Carlyann Flandro

Senior Architectural Conservator, Jablonski Building Conservation, Inc.
avatar for Helen M. Thomas-Haney

Helen M. Thomas-Haney

Conservator, Jablonski Building Conservation, Inc.
Helen Thomas-Haney joined the firm in 2006 and was promoted to principal in 2014. Helen's expertise in developing carefully designed testing programs provide to our clients a better understanding of what is possible in restoration and conservation. A second area of expertise is her... Read More →

Thursday May 30, 2013 3:00pm - 3:30pm EDT
JW Marriott 103-104 19 S West St Indianapolis, IN 46204

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