Managing director at Vertik-Al explains the coating class system and looks at which powder coatings are making the grade

John Park-Davies, managing director at Vertik-Al explains the coating class system and looks at which powder coatings are making the grade.

When it comes to selecting the right powder coating for aluminium windows, doors and architectural metalwork, it helps to understand the class rating. The classes are set by QUALICOAT, the world’s leading quality label for the coating of aluminium, with each coating system evaluated against the scale. The classes rank one to three: Class 1 – Florida exposure one year; Class 2 – Florida exposure three years and Class 3 – Florida exposure ten years.

The class determines the coating’s ability to maintain colour without fading, and retain gloss levels over time, in a harsh environment with high humidity and strong sunlight. The higher the number, the more likely the coating will withstand extreme conditions such as intense sunlight, temperature and exposed locations.

Class 1

This is the most economical of all the classes and the most widely used.  Provided the pre-treatment processes specified by QUALICOAT are followed the durability and adhesion of the finish will be identical to Class 2 and 3 powders. 

Class 2

Also known as super durable powders, they offer enhanced visual integrity, with tighter tolerances over time on colour variation and gloss retention without sacrificing the high substrate protection offered by the powder coating process. 

Class 3

These powders offer an enhancement of the properties of Class 2 powders. They are typically used in extreme locations such as the Middle East.  With the ever-changing climatic conditions across the planet, we are experiencing an increase in enquiries for Class 3 products.

For coastal regions, determined by QUALICOAT as within five kilometres from any coast or tidal estuary the quality label has a specific Seaside Class which is available for all classes of powders.

Rise in Class 2

QUALICOAT grants approvals for coating systems produced by global coating manufacturers. In a letter posted online, President of QUALICOAT, Mo Panam said: ‘Class 2 powder approvals continue to grow; a great reflection of our industry demand for yet higher performing powders.’

Amongst the approved coatings is the Interpon D2000 Series from AkzoNobel, ‘…a revolutionary single coat powder application that achieves a bright metallic finish previously only realised using liquid coatings.’

Metallic Matters

Closer to home, our customers are also requesting metallic finishes. Speaking recently with one customer, an architectural metalwork supplier, he said: “There’s been an awful lot of grey over the past few years.  However, we are starting to see a rise in metallic finishes, especially bronze.  Architectural façade designers are exploring statement exteriors and detailing, using metallics or standard colours like pewter and white in a metallic finish.

“Designers also appreciate that bronze metallic powder coating is a successful alternative to the finish achieved by anodising; it replicates the look without the need for anodisation.” 

Last year, Anodic Pewter, White Aluminium and Gold Metallic all ranked in Vertik-Al’s top 50 powder usage, in metallic finishes.

Class 2 Popularity

We are certainly finding that customers wish to explore the options of Class 2 powders more frequently now. Whether that’s simply because architects and designers are pushing the envelope or if durability and a longer service life are playing a bigger part in the decision-making process. My money is on the latter.

Specifiers, and indeed homeowners, want to ensure the highest level of performance for coated products, lasting the lifetime of the building. For those house buyers purchasing their forever home, they want a product that looks magnificent and gives longevity.

While most colours are available as Class 2 powders, our high usage data continues to be dominated by shades of grey. In the past few weeks alone, there have been three greys in our top five Class 2 powders – RAL 7016, RAL 7004 and RAL 7022. These are complemented on the neutral spectrum by RAL 9005 – Black and RAL 9003 – White in positions two and four, respectively.

Quality Coater

While the durability and performance of the coating is critical so too is the quality of the coater. QUALICOAT also evaluates powder coaters. Requiring independent testing, rigorous controls and random audits, licensed coaters are granted the QUALICOAT quality label. 

There are more than 400 approved coating applicators globally but just a handful in the UK.  Vertik-Al is proud to be one of the UK’s authorised QUALICOAT applicators for paint, lacquer and powder coatings on aluminium for architectural applications and has been QUALICOAT approved since 1994.

As featured in GGP mag (link:

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