Robust coatings take on tropical extremes in Cairns
As part of a $28 million project to rejuvenate the Cairns waterfront, a series of modern steel pergolas and awnings provide restaurant diners with both shade and shelter. Positioned along a granite footpath with lush landscaping, the structures enable year-round dining regardless of the tropical weather, drawing both locals and tourists to the Esplanade Dining Precinct.
However, the structures themselves required robust, long-term protection from the weather. Only a few hundred metres from the ocean, the steel is located in a C4 corrosivity environment. Add harsh UV radiation, high humidity and seeping moisture from the intertwined plantings, and the surface is constantly at risk of rusting, fading and staining.
Collaboration with architect, asset owner and applicator
The architect sought expert advice from David Vivian, Dulux Protective Coatings Sales Coordinator for North Queensland. In consultation with the local Council and the local steel fabricators, David recommended a robust three-coating system.
- Primer: Zincanode 402 at 90 microns DFT
- Intermediate coat: Duremax GPE MIO at 175 microns DFT
- Topcoat: Weathermax HBR at 75 microns DFT
"As well as protecting the steel, we also needed to deliver an aesthetically pleasing finish," David explains. "We encouraged all parties to contact us with any questions or assistance that may have been required, from specification through to application."
The first step was a prime coat of Zincanode 402. This two-pack epoxy and zinc-rich primer provides exceptional cathodic corrosion resistance. It has rapid dry and overcoat times, and offers relatively high build films.
"Zincanode 402 is suitable for use in environments up to 200°C and is often used to coat offshore structures, so it was an ideal primer for a tropical waterfront setting," David says. "Applicators like it because no special sealing or misting techniques are required when overcoating."
Duremax GPE MIO built a second highly protective layer. Locally developed for Australasian conditions, it has been formulated with micaceous iron oxide (MIO) pigment for enhanced barrier protection. It’s also suitable for a wide range of topcoats, including Weathermax HBR, a highly durable polyurethane that can be tinted in over 5,000 Dulux colours.
"Weathermax HBR is our flagship topcoat, often selected to achieve aesthetic values as well as excellent UV and graffiti resistance. For this project, it created a pristine finish in glossy, coastal whites," David explains.
Exciting new spaces
The fresh finish will endure through numerous tropical seasons before needing a repaint. By delivering both style and substance, Dulux PC's system has met the needs of all project partners.
A public opening party in June 2021 saw traders and the public celebrate these exciting new spaces. Cairns Mayor, Bob Manning, said, "Our locals and visitors bring the Esplanade to life and we can’t wait to see even more people jogging, walking, dining and admiring the beauty of what Cairns has to offer."
Dulux PC's coatings experts can help you meet diverse criteria on your next project. Contact us for technical advice tailored to your project.