When selecting a finish for architectural aluminum products, color often drives the final decision. Architectural paint coatings offer a nearly unlimited palette of choices, but current global supply chain disruptions and price increases may impact the final schedule and budget. When a project’s desired look emphasizes metallic colors, anodize can provide a similar aesthetic with some advantages.
The Forge, New York CIty. Photo: Eduard Hueber, ArchPhoto Inc., courtesy of Linetec.
Anodize finishes are readily available, extremely durable and cost effective, making them an equal-or-better alternative to paint for natural metallic colors.
Anodizing protects and enhances the aluminum in both exterior and interior applications, such as:
- Window, skylight, curtainwall, storefront and entrance framing systems
- Doors, column covers, wall panels
- Façade and rainscreen systems
- Canopies, sunshades and other shading devices
- Coping, fascia and louvers
- Ornamental and decorative elements, trim and railings
Unlike painted coatings that adhere to the surface, an anodize finish is an integral part of the aluminum substrate. The color is generated by immersing the aluminum extrusions or sheets in a bath containing an inorganic metal, such as tin, cobalt, nickel or copper. The metal used and the amount of time the aluminum is immersed determines the final color.
The color range for anodized architectural aluminum is a limited, but desirable, spectrum of metallic tones. The color selection is reminiscent of steel, bronze and copper, yet retains all the benefits of aluminum. The finished material can be fabricated into almost any shape. It can be thermally improved to support energy efficiency. It also is lightweight for shipping and installation.
Architectural anodization results in an exceptionally durable surface that is as hard as a sapphire, the second hardest substance on Earth. Anodized aluminum’s high performance resists the ravages of time, temperature, corrosion, humidity and warping. It is an inert material that is not combustible and poses no health risks. It does not attract pests, it takes very little maintenance throughout its long life and it is infinitely recyclable.
Beyond these practical advantages, the aluminum’s natural, elemental aesthetic is highlighted by an anodize finish. Instead of using silver-colored paint to achieve the desired effect, consider the clear anodize. The anodized aluminum’s original color takes center stage, while the underlying metal remains protected.
If a project calls for a deep wine color or luxurious copper, remember that paint is not the only choice. Specialty options are available in anodize. Bordeaux anodize delivers an earthy metallic option to burgundy paint hues with a matte finish. Copper anodize retains its initial shine and does not patina or stain adjacent material.
A long immersion in the anodize coloring tank will result in a dark metallic black that can be used as an alternative to steely black paint. Because the color is integral to the aluminum, it also imparts the solid feel of an all-metal product.
Neutral and subdued palettes are predicted as balanced, comforting color trends for 2022. Tan and brown tones are an increasingly popular choice for natural-looking bases and biophilic accents. Rather than picking from hundreds of brown paint swatches, bronze anodize simplifies selection to light, medium, dark or extra-dark. Champagne tones represent the light neutral range of the traditional anodize color offering.
Regardless of the color, remember to specify that all exterior product applications should meet AAMA 611, Voluntary Specification for Anodized Architectural Aluminum. Published by the Fenestration and Glazing Industry Alliance, this document was updated in 2020. Anodize finishes meeting current Class I specification standards provide high-performance resistance to abrasion, weather, UV exposure and salt spray, and exceptional wear in high-traffic environments.
A warranty of up to 10 years is typical for Class I anodize finishing, although the expected life span of anodized aluminum products can be 40 years or more. Finishing service providers also can provide material ingredient and green building documentation, and other creative options to meet the aesthetic, performance, scheduling and budget needs of a project.
Tammy Schroeder, LEED Green Associate, is a marketing manager at Wausau, Wis.-based Linetec. With more than 20 years of experience in the finishing industry, she serves as an industry educator on high-quality, high-performance architectural coatings and services. Schroeder can be reached at tammy.schroeder@linetec.com. To learn more, visit www.linetec.com.