Construction Specifier column addresses “Avoiding Color Variation with Anodize Finishes”

champagne range sample

Linetec Champagne anodize range sample

Learning from failures are some of the most difficult and most valuable lessons. Many times, failures can be avoided if we turned to those with more experience for advice. The Failures column in the January issue of Construction Specifier takes this approach issue and shares advice on “Avoiding Color Variation with Anodize Finishes.”

Authored by Linetec’s Tammy Schroeder explains the variables affecting color in the anodize process, and the challenges of achieving an exact color from run to run and load to load.

To minimize color variation, she offers five tips:

  1. Maintain metal consistency – The easiest way to ensure this is to work with one metal source/extruder per project and request all metal come from one lot of material.
  2. Do not mix aluminum alloys, as even mixed tempers will not produce uniform results – For best results, use 6063 alloys for extrusions and 5005 for flat sheet stock and fabricated parts. When structural alloy is required, 6061 and 5052 can be used, but will not give similarly acceptable results.
  3. Perform as much bending and forming as possible prior to finishing – Anodic films are very hard, and as a result most post-production bending causes the film to “craze,” which produces a series of small cracks in the finish, giving it a spider-web like appearance.
  4. Be aware of anodizing’s effect on welds – The heat developed from the welding process changes the metallurgy on nearby metal or heat-affected zones, causing localized discoloration (i.e. halo effect), so one should use the proper 5356 alloy welding wire and lowest heat possible.
  5. Select an anodizer that uses automation – This helps to reduce inconsistencies in the process.
dark bronze range sampeles

Linetec dark bronze anodize range samples

Click here to read the whole Failures column, and please contact us for personalized service in avoiding color variation and selecting the correct finish for your next project.

AAMA updates paint specifications to -17

AAMA-proud memberThe American Architectural Manufacturers Association (AAMA) regularly reviews and updates its specification documents, including for painted coatings. The association’s Aluminum Material Council’s Finishes Committee has adjusted AAMA 2603, 2604 and 2605. The most current versions are denoted as 2603-17A, 2604-17A and 2605-17A.

What’s changed?

In the updated AAMA specifications, the procedure rating the adhesion of coatings to different substrates (via tape test) has been removed. Those standards are still required to meet AAMA’s guidelines, but now Section 8.4 Peel Adhesion refers the reader to ASTM D3359 to find the details on tape testing. These AAMA specifications also reference ASTM D3359-17 for the new requirements for tapes used in adhesion testing.

Section 8.4.1 now clarifies that all tests shall be performed in the sequence they appear in the document. Connected to this, the order of testing has been changed in the specifications. References to subsections of 8.4 also have been updated in Section 5.5.

What’s remains the same?

As a member of AAMA, Linetec stays up to date on these stringent industry standards and documents. We are committed to ensuring our customers’ finishing specifications are met on every project.

For a quick refresher, here’s what to remember about AAMA 2603, 2604 and 2605:

AAMA 2603 – typical for interior specifications

Required to show only “slight” fade and chalking after one year, AAMA 2603 has no specifications for gloss retention and erosion resistance. Baked enamel (acrylic/polyester) paints should meet AAMA 2603. These painted finishes are less expensive than fluoropolymer resin-based coatings, but have poor resistance to color fading and chalking. Baked enamel coatings are harder than fluoropolymer and can be used for interior application where color retention is not required.

AAMA 2604 – an “intermediate” specification

AAMA 2604 specifications are more demanding. If a finish qualifies, then five years after its application the color must have faded no more than 5 Delta E, the chalking no greater than 8, the finish still retain 30% of its gloss and no more than 10% of it has eroded. This finish will provide good color and gloss retention. It also will provide good hardness and abrasion resistance. Painted finishes meeting this specification typically are a 50% fluoropolymer resin-based coatings and are commonly applied on aluminum storefront framing, entrances or other high-traffic areas.

AAMA 2605 – the specification for high-performance exteriors

Ten years after it has been applied, an AAMA 2605 paint will have faded no more than 5 Delta E, the chalking will be no higher than 8, 50% of its gloss will still be retained and only 10% of the film will have eroded. These finishes exhibit outstanding resistance to humidity, color change, chalk, gloss loss and chemicals. Painted finishes meeting this specification typically are a 70% fluoropolymer resin-based coatings and are commonly applied on aluminum framing and systems for monumental architectural projects.

For personalized assistance in selecting and specifying the right coating for your aluminum building products, please contact Linetec’s regional sales managers , email or call 888-717-1472.

To download the latest version of these, or any, AAMA documents, visit the AAMA Publication Store

What are common paint defects? How do you minimize them?

ILRegatta_MagellanSelecting the proper architectural paint for a project’s architectural aluminum products can ensure a visually pleasing result for years to come. Even when the correct painted coating is chosen, other factors can cause unforeseen defects to the aluminum product’s surface. Here are some common flaws that may occur, and how to correct or avoid them.

Pretreat the Metal, Dry Thoroughly

The condition of the surface to be coated plays a big role in the final product. The presence of oil, grease or other contaminants can cause adhesion failure in the paint. This could result in the topcoat peeling or flaking off. The rolling process of tubes and extrusions also can leave such a residue. For architectural finishes applied at a paint facility, baking of the paint after application is required, any reside not removed prior to painting, may run, or leach out, from beneath the coating, damaging both the paint and metal.

Your finishing applicator can avoid these flaws by pretreating the metal before paint ever touches it. Using a combination of high-power water rinses, high-temperature acid clean, etch and desmut and a chromium phosphate coating will remove most contaminants and increase the corrosion-resistance of the aluminum. A thorough drying process afterward will ensure that any remaining moisture is evaporated and that the finishers have an ideal surface on which to work.

Know Your Oil

Non-water soluble oils can lead to “fisheye” problems. Fisheye is a defect where circular depressions or “craters” appears in the finish. Most pretreatment systems are not equipped to remove these oils in advance, so if you suspect them to be present on your surface, be sure to discuss this with your finisher.

Watch for Corrosion

If the metal was stored outside before painting, it may suffer from corrosion in spots, which will stain in areas after being finished. Corrosion can be minimized or removed entirely by sanding the affected areas of the metal prior to finishing.

spray application4Apply with Care and Control

The process of paint application also can cause defects to appear later. Blisters or “pops” can appear beneath the surface of the finish after the curing process is complete, if there wasn’t enough flash off time before baking. Inconsistent coloring can occur in the paint if its application was inconsistent or the thickness of the finish varies across the surface. This will result in a coat that has color variation throughout, particularly if viewed from different angles.

These flaws can be avoided by quality-controlled, standard operating procedures for paint application on the part of the finishers. By applying the coating consistently throughout the process, the finishers can ensure less variation in the end product. A combination of automated spray equipment and painting specialists, helps to ensures an even, gradual coating application to prevent film build-up.

Send a Sample

If you are still concerned about the opportunity for defects in your architectural paint, consider sending a sample sheet of the metal that will be used to your finisher, as a mock-up, in advance. By applying the exact process that would be use for your actual project, any potential flaws can be identified and corrected in advance.

ArchResourceImage-arch resource center

Learn more about Linetec’s quality control and paint finishing services by clicking here . For personalized assistance in selecting the right coating for your aluminum building products, please contact Linetec’s regional sales managers , email or call  888-717-1472



Anodize Nickel Test


Nickel Test

When extreme hardness is required for aluminum building components, such as in high-traffic areas, like entranceways and railings, an AAMA 611-14 anodized aluminum finish should be specified.

The hardness of anodized aluminum rivals that of the diamond.

This “Nickel Test” demonstrates why a Class I high-performance anodize coating is the perfect choice for exterior architectural applications.

Architectural Paint Data Sheet

Process  .  Warranty  .  AAMA Specifications  .  Guide Spec

Architectural-Paint-Data-Sheet-1Download complete data sheet

High-performance fluoropolymer resin-based coatings may be defined as a thin layer of plastic film containing resin, binder and pigments that is applied to the surface of an object to provide protection and a decorative organic coating. The exact composition of a particular paint coating is often complex and proprietary.

Fluoropolymer resin-based coatings provide protection against… read more

High-Performance Architectural Paint Process

Paint systems are designed to be applied over clean metal that has been properly pretreated.

Without a proper pretreatment, delamination will likely happen within the first year of installation. To prevent, and warranty against, this type of failure a chrome-type pretreatment is recommended.    read more

ArchResourceImage-LinkedInStrengths of High-Performance Paint

  • Color Retention (UV resistance)
  • Salt-spray resistance
  • Vast array of color choices
  • Paint protects and maintains the structural integrity of the aluminum
  • Field touch-up / repainting capabilities
  • Small-batch and custom color capabilities – fast and cost effective

Paint Warranty

Projects painted by Linetec, utilizing liquid PVDF resin-based coatings, are warranted by the strength of both Linetec and the paint manufacturer. Linetec’s documented testing allows us to offer warranties of 10 years, on high-performance (AAMA 2605) coatings, with confidence that your product will perform as intended.

In some cases, with prior approval and a minimal up-charge, Linetec can offer an extended warranty up to 20 years on AAMA 2605 coatings. read more

AAMA Specifications

In order to ensure the paint performance expected for an architectural / commercial application, AAMA 2605 specification should be referenced along with the paint color.

Beyond the stringent standards and regulations, Linetec offers a downloadable guide spec with specifiable differences that contribute to a project’s long life, durability and sustainability.   read more

Damaged_Anodize-McDonalds door-brickwashCleaning and Maintaining your Aluminum Finish Guide

This paper discusses the recommended care of painted and anodized finishes on architectural metal and examines three levels of concern: care and cleaning, minor repairs, and more complex refinishing.             read more

Construction Specifier shares Linetec’s anodizing expertise

Flapper2-webThe April issue of Construction Specifier features “Five Factors for Variation in and Anodize Finish,” authored by Linetec’s Tammy Schroeder.

The six-page educational article describes the anodizing process and key considerations to minimize color variation. These essential factors include:

  • Aluminum alloys and their alloying elements
  • Mixing aluminum alloys means mixed results
  • Primary vs. secondary aluminum
  • Chemistry of the anodize process
  • Surface preparations

Construction Specifications Institute members received the printed magazine, and all can view the feature online, page 62.

After April, please visit to create a free account and access the archived digital editions.

Follow the links to learn more about Linetec’s anodize process and how we ensure the most consistent color.

How long will my paint’s color last?

PRESTON-HYUNDAI-1---Preston-MD=webFrom the moment painted coating is applied to a surface, it begins to degrade from exposure to the elements. Over time, the difference between a coating’s original and current color becomes more pronounced. Selecting a coating designed for the environment where the painted aluminum product is installed, and taking steps to protect it, will help ensure color that lasts as long as possible.

When discussing how long a painted coating’s color will last, we usually refer to “fade.” Fading occurs from the oxidizing or leaching of pigment from the paint, causing its color to alter from its original application. Intense UV radiation (i.e. daylight) also causes fading. All paint color will fade eventually, but the degree of fade can be reduced with knowledgeable selection and basic maintenance.

Specifying for Fade Resistance

The American Architectural Manufacturers Association’s industry-leading performance standards – AAMA 2603, 2604 and 2605 – for architectural painted coatings specify color retention in terms of Delta-E (dE). A dE is a unit of measurement between two colors where 1.0 is the smallest difference a human eye can see. As time passes and a finish drifts from its original hue, its dE increases.

  • AAMA 2603 requires that a paint show only “slight” fade after one year. This pertains to baked enamel coatings typically used for interior application where color retention is not a large concern.
  • AAMA 2604 requires that a painted coating must not fade more than 5 dE over five years. This pertains to 50% PVDF resin-based coatings and typically is used for storefronts, doors or other high-traffic areas.
  • AAMA 2605 requires that a painted coating must not fade more than 5 dE over 10 years. This pertains to 70% PVDF resin-based coatings and typically is used for curtainwall and window wall on monumental architectural projects.

Formulating for Vibrant, Durability

The composition of a paint’s pigments will influence how quickly it fades. Inorganic pigments fade more slowly than organic pigments. Some brighter, more vibrant colors – such as bright red – traditionally use organic pigments to achieve their desired hue. The organic pigment’s greater susceptibility to fading can be combatted by applying a clear-coat over the topcoat of paint. This helps minimize UV exposure to the more vulnerable pigment.


Image shows fade comparison of Kynar 500 (AAMA 2605) to Polyester (AAMA 2603)

Cleaning for Longevity

Once applied, even a durable finish will require occasional cleaning to slow its fading. Avoid cleaning a coated surface with strong acid or alkali cleaners. Instead selecting a mild soap solution for washing your finished surfaces.

Learn more about color retention and Linetec’s paint finishing services by clicking here . For personalized assistance in selecting the right coating for your aluminum building products, please contact Linetec’s regional sales managers , email or call 888-717-1472.