Helen M. Thomas-Haney and Xsusha Flandro discussed their research and investigation of restoring aluminum finishes at a train station. Discovered in 1825 by Hans Christian Oersted, aluminum was used in jewelry and decorations into the mid-nineteenth century. The first architectural use of aluminum in the United States was for the cap of the Washington Monument in 1884. As production increased and price decreased, aluminum began to be more widely used in commercially available products. By the 1920s, aluminum was being used on many buildings in Vienna, in modernist movement buildings, and on the Empire State Building. Companies such as ALCOA Aluminum advertised aluminum as weather resistant and structurally sound. It’s ease of being manipulated made aluminum popular as decorative ornamentation on exteriors, but also in Art Deco interiors.
Built in 1932, the train station was constructed of a copper roof, pine ceiling, and aluminum arch spandrels. The station had alterations over the years, including lead paint, the addition of billboards that pierced the aluminum panels, and graffiti. The conservation project began with research into project specifications, original drawings, and original finish specifications. Through research and material evidence, it was clear that the aluminum spandrels had three different types of mechanical finishes. Based on the historical terminology, these were identified as “satin”, “sand-blasted”, and “sand-blasted deplated”. The station remained in service during the restoration, so precautions were taken during paint removal and repair work. After the paint was removed, two different types of corrosion were revealed. Corrosion was especially significant in areas where the differing materials joined. Based on the containment issues caused by sandblasting to remove corrosion, other means of removal were necessary. Some corroded areas were patched and repaired, while other panels were taken offsite for restoration.
After surface preparation, the finishes were recreated in-situ. The “satin” finish was recreated by hand sanding with a coating to prevent corrosion. Initially, a bristle-blaster was used for the “sand-blasted” finish, but it did not complete the desired effect. The team later used aluminum oxide blasting for the finish. The “sand-blasted deplated” finish was completed with an aluminum patination process with a black patina buffed to gray.