Metal Finishes vs Surface Finishes for Aluminum Extrusions

Metal Finishes vs Surface Finishes for Aluminum

Metal Finishing

  • Anodizing is an electrochemical process that involves submerging the aluminum extrusion in a chemical bath. This adds a protective coating over the aluminum that can also change the appearance. Anodizing is frequently used for applications where your aluminum would be exposed to the elements or where you require a highly professional and clean piece of aluminum. Oftentimes corner guards, slatwall inserts, and store fixture extrusions are anodized for both appearance and protection. Common colors of anodizing include clear satin-etched and anodized, black, bronze, nickel, and brite dip.
  • Painting metal is a similar process to applying paint on just about anything else. Adding a wet paint over the surface of the aluminum can change the appearance and slightly increase durability. Often metal finishers will use a paint sprayer or pump rather than a brush or roller to ensure that the finish is both smooth and consistent.
  • Powder Coating gives a similar appearance to painting, however, is much more durable than standard wet paint. The process of powder coating an aluminum extrusion involves covering the metal in a statically charged and colored powder and then heating the extrusion in a specialty oven which melts said powder creating a smooth and evenly distributed finish.
  • Sublimation includes a base coat of powder followed by a thin layer of film that has a pattern on it. This film is then removed and when the metal has cooled the pattern appears. Sublimation most commonly creates a wood-like pattern but can be altered to achieve any pattern or design you would like! Stackable slatwall, or interlocking slatwall, is often finished with sublimation to give the appearance of a wood slatwall solution while still maintaining the strength of an aluminum solution.
  • Plating includes covering the aluminum extrusion or other metal with an additional layer of metal. When plating things, often the terms gold-plated or silver-plated come into play. This finish can be applied with an electric current (electroplating) or with autocatalytic chemicals (electroless plating).

Surface Finishing or Mechanical Finishing

Surface finishing refers to processes that alter or remove a layer of the metal that is being finished. This is often done to improve the appearance or functionality depending on the application. Common methods of surface finishing aluminum trims and extrusions include brushing, grinding, polishing, milling, and blasting.

    • Typically a brushed aluminum finish or grained finish is performed prior to anodizing with specially designed equipment that brushes the material in a uniform or straight pattern. The material is sent through a series of brushing wheels that removes a thin layer of the metal that creates a uniform grain or brushed pattern along the surface. Brushing is commonly used when the aluminum extrusion has some knicks or surface scratches that need to be removed for a cleaner appearance. Clear or stain anodizing the brushed surface creates a very durable and consistent finish.
    • Grinding down aluminum extrusions smooths the surface of the material at hand. There are a variety of grinding machines and methods each of which can be expertly used to create the desired level of smoothness on your material.
    • Milling, or producing a mill finish, is when the metal is passed through a rolling mill, an extrusion die, or drawing process. This is the basic finish of aluminum extrusions and is what is used in metal finishing processes at Eagle Mouldings. Mill finishes are often rough to the touch, show extrusion lines, and other blemishes associated with running the extrusion.
    • Blasting is a method of surface finishing that both cleans and finishes metal. Abrasive blasting consists of using high amounts of pressure to propel particles across a metal surface. Common mediums used in abrasive blasting include sand, glass, steel grit, water, and dry ice.

Finishing Services at Eagle Mouldings

Eagle Mouldings is the premier supplier in the aluminum extrusion industry and has the capabilities to custom finish any of our stocked aluminum trims and extrusions and even can create a custom aluminum extrusion that fits your specific needs or applications from start to finish. It is your job to have ideas and it is our job to bring them to life. Call our knowledgeable customer service team or submit a quote request online for more information about our products and services.