How To Choose The Right Aluminum Coating For Your Design

November 1, 2021

Aluminum canopy systems are widespread and commonly used in all building types, from high-end residential buildings to commercial, retail, hospitality, institutional establishments, and more. Customizable aesthetics, durability, cost-effectiveness, and non-corrosive properties are just some of the strengths that make aluminum a popular choice among architects and designers. 

Although aluminum does not rust, it is susceptible to oxidation when exposed to oxygen. Therefore, the necessity to protect and preserve the material's structural integrity over its long lifecycle gave rise to aluminum coatings. So, in this article, we'll talk in-depth about the different types of aluminum coatings we offer and the advantages of each. Let's dive in!

TYPES OF ALUMINUM COATINGS

The aluminum coatings available can be categorized into four types: Anodized, Fluoropolymer, Baked Enamel, and Wood Grain Powder Coating. First, let's take a look at anodized aluminum and its different types. 

ANODIZED ALUMINUM

Anodizing is an electrochemical finishing process that creates a coating of oxide on a metal's surface, strengthening corrosion resistance and increasing durability. To prepare aluminum for anodizing, it is properly washed and rinsed before being immersed in a series of tanks, one of which contains an electrolytic solution like sulfuric acid. After various electrochemical reactions, an anodic oxide barrier layer forms on the surface of the extruded aluminum component.

The anodized coating is an integral, hard substance that protects the base metal and makes it resistant to chipping, peeling, or flaking. The life of the anodized finish depends on the thickness of the coating applied.

There are two types of aluminum anodizing: Clear Anodizing and Color Anodizing. Color anodization is achieved through a process called diffraction. One thing to keep in mind when recommending color anodized finishes is the color palette. We’ll cover more about that shortly. 

CLEAR ANODIZING

Clear anodizing is a process of anodizing that is achieved without the use of any dyes. It's more forgiving than darker anodized colors, which are more likely to show color inconsistency and imperfections when installed on-site.

COLOR ANODIZING

Color anodizing is primarily available in clear, champagne, and bronze. Many factors determine the end result of color anodized finishes, such as aluminum grade, component sizes, aluminum alloys, finish type, etc. Large-scale projects can present challenges with color consistency as they require multiple batches of the anodizing bath, further increasing the risk for inconsistency. 

PROS OF ANODIZED ALUMINUM

  • Long-lasting natural finish
  • Easy to dye and clean 
  • Cost-effective in the long run 
  • Highly durable
  • Corrosion and weather resistance 
  • Fade-resistant and unaffected by the sunlight
  • Environmentally friendly

CONS OF ANODIZED ALUMINUM

  • Color options are limited
  • Difficult to touch up in the field
  • Prone to mineral deposits
  • Color inconsistency due to aluminum alloys and elements
  • Color inconsistency with large pieces 
  • Surface imperfections in the aluminum may be visible through the anodize

FLUOROPOLYMER (KYNAR 500 70% PVDF)

Kynar finishing is a premium finish that provides a very consistent end product when compared to anodized coating. Also known as fluoropolymer, it offers uniform thickness and doesn't require any special application equipment, making it a versatile choice for projects with a low budget.

This option offers a greater variety of colors and tints that can be manufactured in smaller batches and is easy to mix and match, making it an ideal choice for painters and consumers.

Valspar's Fluropon 70% PVDF Extrusion Coating consists of pigment, resin, and solvent that together, provide excellent superior color retention, high resistance to UV radiation, and resistance to both chalking and chemical degradation. This 2-coat system meets AAMA 2605 requirements and includes a primer for corrosion resistance, as well as a topcoat that determines color.

Despite the apparent benefits, painted aluminum surfaces are prone to scratching. Depending on the extent of the damage, painted surfaces can be restored with touch-up paint on site. 

PROS OF KYNAR 500

  • Nearly unlimited color choices 
  • Color consistency
  • UV and humidity resistance
  • Field touch-up capability
  • Resistant to corrosion

CONS OF KYNAR 500

  • Susceptible to scratches
  • Higher cost in comparison

BAKED ENAMEL

When using a baked finish, an enamel coating is applied directly to the metal eliminating the need for a primer. Baked enamel finishes are a one-coat system that is heated, or baked, at temperatures of at least 150 degrees. As a result, the finish is thick and resistant to the typical wear and tear seen with metals. This finish is typically used in interior applications as they offer a lower level of protection compared to other coating methods.

PROS OF BAKED ENAMEL

  • Cost-effectiveness
  • Harder coating compared to Kynar
  • One-coat application
  • Wide range of color choices
  • Field touch-up capability

CONS OF BAKED ENAMEL

  • For applications that don’t require color retention, chalk, fade, and weatherability

WOOD GRAIN POWDER COATING

Wood grain powder coating is an eco-friendly finish that has the appearance of traditional wood with the strength of aluminum. Unlike aluminum, real wood is likely to warp, split, or eventually rot, especially in harsh outdoor conditions. The beauty of wood and the durability of aluminum are combined in one simple to specify process. There are textures for every project, ranging from bright to dark and everything in between. Aside from wood grain textures, premium alternatives such as stone and marble patterns, rust, blackened steel, and custom graphics such as a logo are available.

Powder coating is the process of applying a free-flowing, flour-like powder to an electronically grounded part using an electrostatically charged spray gun. Afterward, the part then goes into a curing oven, where it creates a “skin”. When the "skin" dries, it forms a firm, durable finish resistant to scratches, cracking, peeling, UV rays, and rust. It's considered environmentally friendly as it doesn't contain any VOC and complies with AMAA 2065 standards. 

PROS OF WOOD GRAIN POWDER COATING

  • Lightweight
  • Resistant against scratches and peeling
  • Environmentally friendly method
  • Virtually any pattern is achievable
  • Does not rot, warp, or split like traditional wood

CONS OF WOOD GRAIN POWDER COATING

  • Difficult to touch up in the field
  • Longer lead time for samples and color matching

Anodizing and other coatings play a major role in aluminum part protection. However, which aluminum finish to apply is not merely a matter of personal preference, as it largely depends on the application purpose. 

It's recommended that designers and building owners choose coating options based on specific criteria like desired aesthetics, initial costs, field performance over time, etc.  

To make an informed decision based on the specific recommendations for your next project, please get in touch with us! At AVAdek, we can help you determine the best finish possible that meets your project requirements.



AVAdek
12130 Galveston Road BLDG 1, Webster, TX 77598
713-944-0988 / 800-777-4031