For years, discussions about protecting metalwork in the UK have centred on rain, frost, road salt and corrosion. But as anyone who has experienced the recent heatwaves will know, our weather is changing.
With temperatures climbing well above what many of us would have expected just a decade ago and prolonged periods of intense sunshine becoming more common across both the UK and Europe, another question is beginning to emerge: Can powder coated finishes cope with increasing heat and UV exposure?
The good news is that, when the correct coating system is selected, the answer is yes.
Many people assume it’s simply the heat that damages painted surfaces. In reality, ultraviolet (UV) radiation is often the bigger challenge.
Over time, UV exposure can cause some finishes to fade, lose gloss or become chalky. This is why choosing the correct powder coating for an outdoor application is so important.
Modern polyester powder coatings are specifically formulated for exterior use, providing excellent resistance to UV degradation while helping colours remain vibrant and finishes retain their appearance for many years. For projects requiring exceptional long-term performance, super-durable architectural powder coatings offer even greater colour and gloss retention in demanding climates.
Although recent UK temperatures have felt extreme, they’re still well within the operating range that quality powder coatings are designed to handle.
Remember that powder coatings are cured in industrial ovens at temperatures of around 180-200°C during manufacture. Once fully cured, the coating forms a tough, cross-linked surface designed to withstand years of environmental exposure.
That doesn’t mean every application is suitable for every temperature. Components that experience continuous extreme heat – such as exhaust manifolds or industrial furnaces – require specialist high-temperature coating systems rather than conventional exterior powders.
However, for architectural steelwork, railings, balconies, gates, street furniture, cladding and commercial fabrications exposed to direct summer sunshine, quality powder coating continues to perform exceptionally well.
One interesting consideration that is becoming increasingly relevant is colour.
Dark colours naturally absorb more solar energy than lighter shades, meaning black or anthracite (dark grey) surfaces can become noticeably hotter in direct sunlight than white or lighter finishes.
While this doesn’t normally damage the coating itself, it can influence the temperature of the underlying metal and may be worth considering where users regularly touch the surface, or where thermal expansion is an important design factor.
One of powder coating’s greatest strengths is that it’s designed to withstand environmental extremes.
A properly prepared and professionally applied coating doesn’t just protect against rain and corrosion – it also offers long-term resistance to sunshine, moisture, temperature fluctuations and weathering throughout the seasons.
In fact, many architectural powder coating systems are tested to perform in some of the world’s most demanding climates, from intense UV exposure to coastal environments with salt-laden air.
As with most things in engineering, preparation matters.
Surface preparation, correct pre-treatment, the right powder specification and proper curing all play a significant role in determining how well a finish performs over its lifetime.
That’s why choosing an experienced powder coating specialist is every bit as important as selecting the right colour.
The UK’s climate may be changing, but powder coating has long been engineered to cope with challenging environments.
Whether your project needs to withstand winter storms, coastal conditions or increasingly hot summers, selecting the right powder coating system can provide a durable, attractive finish that continues to perform year after year.
If you’re specifying metalwork for an outdoor project and want advice on selecting the most suitable powder coating finish, the Tomburn team would be happy to help. Get in touch and tell us more about your project.
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