Formulators Forum: Dust-on-Dust Powder Coatings: A Breakthrough in Energy and Efficiency

By Rob Breitzman

Innovation often stems from necessity. Around 2010, a surge in edge corrosion failures across the agricultural and construction equipment market prompted the need for more consistent coverage and durability. At the same time, the trailer market was pushing to improve process efficiency without compromising performance.

This inspired formulators to rethink the conventional two-coat process. In response to the need, a dust-on-dust powder coating system (also known as dry-on-dry) that delivers the performance of a two-coat finish with the efficiency of a single cure was created.

From Two Coats to One Cure

Traditional two-layer coating systems cure the primer before applying the topcoat, requiring significant line space or dual oven capacity—resources many OEMs lack.

Sherwin-Williams OneCure™ eliminates this step by enabling both layers to be applied and cured together in a single bake. This dust-on-dust system reduces energy consumption and operational footprint while often enhancing corrosion resistance and appearance standards.

Because large components are often heavy-gauge and geometrically complex, conventional two-step processes require long heating and cooling periods — sometimes up to two hours per part. The dust-on-dust approach removes a full thermal cycle, enabling manufacturers to streamline production and deliver protection that lasts in the most demanding environments.

Versatility Across Markets

Dust-on-dust technology is now applied in a range of markets demanding durability, edge protection, and aesthetic finishes, including trailers, commercial vehicles, propane tanks and electric vehicle (EV) charging stations.

To fit the diverse needs of multiple markets, this portfolio of products includes several primer chemistries that can be applied with the dust-on-dust technique:

• Polyester primers provide application flexibility, edge coverage, aesthetics and irreclaimability.

• Hybrid primers provide a balance between corrosion resistance and appearance.

• Epoxy and zinc-rich epoxy primers provide corrosion resistance for trailer and commercial vehicle OEMs.

These primers are topcoated with superdurable polyester that are triglycidyl isocyanurate (TGIC)-free coatings and are ultraviolet (UV) durable. The dust-on-dust powder coating system can be formulated in a range of colors, gloss levels, textures and effects. This flexibility enables tailored performance while considering environmental or regulatory demands.

Chemistry Behind Compatibility

The heart of dust-on-dust performance lies in formulation balance. Each layer must perform its function while remaining fully compatible during co-curing. For high volume colors, the primer and topcoat are color matched in polyester systems to ensure consistent appearance and superior edge coverage.

This compatibility was achieved through extensive experimentation with resin chemistry and crosslinking kinetics, which led to the development of a superdurable polyester that offers extreme edge protection and corrosion resistance. During co-curing, the layers stratify and interbond, forming a continuous film that eliminates risks of intercoat adhesion failure.  

Efficiency and Application Advantages

By removing the first bake and cooling cycle, facilities can cut total oven time and related energy usage. For components that traditionally require a full reheat to 345°F and subsequent cooldown to 125°F before handling, this represents time, energy and cost savings. Low-cure options are also available across polyester, epoxy and zinc-rich systems, offering curing temperatures as low as 280°F to 320°F.

Beyond curing efficiency, advancements in dust-on-dust powder formulation and charge control led to a 30% to 40% increase in transfer efficiency and reduced back ionization. These improvements simplify application on complex parts such as welds, corners and edges — areas most prone to corrosion. These systems run on standard application equipment, requiring minimal process change or operator retraining.

Sustainability and Future Development

Energy efficiency remains one of the most significant sustainability gains of the dust-on-dust approach. With one less oven cycle, manufacturers can reduce overall energy use, conveyor movement and emissions. Research continues into integrating low-cure and bio-based formulations that could further reduce energy input and carbon footprint.

Rob Breitzman is senior group leader, North America Powder Lab at Sherwin-Williams.