Optimal Procedures for Preventing Powder Coating Chalking

How to prevent chalking and achieve a flawless, durable finish even in unfavourable conditions

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Imagine you have received a request for a very important coating project. After weeks of hard work, you have finally completed the project. Each piece has been coated with care and precision, and you are satisfied with the final result. The customer is happy and everything looks perfect. After not even a year, however, you receive an unexpected call: ‘The coated surface is covered with a whitish powder: what is happening?’

This phenomenon, known as chalking, is a common problem in powder coating and can compromise both the aesthetics and the coating’s protection.

What is chalking?

Chalking occurs when the coated surface starts to leave a white, powdery residue. This defect not only makes coated surfaces less attractive but also reduces the protection offered, resulting in a loss of the coating’s chemical and mechanical properties and exposing the substrate to potential attack from external agents.

Impact of chalking on the surface

Chalking is not just an aesthetic problem. White dust that forms on the coated surface can compromise the integrity of the coating, reducing corrosion protection and creating damage such as oxidation and wear. This can lead to a significant reduction in the life of coated items.

What are the main causes?

• UV exposure: UV radiation, especially if for a long time, can degrade coating binders and cause chalking. This problem is widespread when it comes to items intended for outdoor use and constantly exposed to sunlight
• Low-quality coatings: Products not formulated to withstand particularly unfavourable environmental conditions can quickly become damaged. Low-quality coatings often contain no UV-stabilising additives, making the surface more susceptible to chalking
• Adverse environmental conditions: Moisture, heat, and weathering can accelerate the chalking process. Temperature extremes can cause the coating to expand and contract, contributing to its degradation

How can we avoid this?

An essential step to avoid chalking is to choose high-quality powder coatings formulated to withstand UV radiation and adverse environmental conditions.

Solutions for a flawless, long-lasting finish: RIPOL Polyester Systems

RIPOL has developed a range of polyester powder coatings to effectively prevent chalking, that offer excellent UV resistance and chalking-free characteristics. These systems are ideal for coating materials intended for outdoor use and are available in different types and series to meet the specific needs of various sectors.

• RIPOL Series 5 Systems for Architecture: Used mainly in the architectural sector to coat aluminum profiles, door and window frames, façade cladding, and steel and galvanized steel items. They are QUALICOAT and GSB certified for their durability and provide long-term protection against chalking
• Super-hardening systems for the ACE sector: These polyester resin-based systems are formulated with heat- and lightfast pigments, making them perfect for coating agricultural machinery, earth-moving equipment and automotive accessories
• RIPOL Series 6 Classic systems for general industry: They offer good resistance to weathering and UV radiation, high mechanical properties, and good chemical resistance. They are particularly suitable for coating metal structures and materials intended for outdoor use, such as gates, garden furniture, agricultural equipment, bicycles and road signs

By using RIPOL Polyester Systems, you can effectively prevent chalking and ensure lasting protection of your powder-coated products.

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Visit our website or contact our team of experts for more information and to learn how these systems can improve your applications.