When it comes to finishing metal, most customers instinctively reach for a tin of paint. But if you’re looking for a finish that lasts — really lasts — it’s worth understanding what your options actually are.
Powder coating and wet painting are the two main contenders, and the difference between them matters more than most people realise.
How They Work
Wet painting is exactly what it sounds like: liquid paint applied by brush, roller, or spray. It relies on solvents to keep the pigment in suspension and dries as the solvent evaporates.
Powder coating is a dry process. A finely ground pigment and resin mixture is electrostatically charged and sprayed onto the metal surface. The part is then cured in an oven at around 180–200°C, where the powder melts, flows, and fuses into a smooth, hard finish.
Durability
This is where powder coating pulls clearly ahead. The curing process creates a molecular bond that is significantly harder and more resistant to chipping, scratching, and fading than conventional wet paint.
Powder-coated surfaces routinely last 15–20 years with minimal maintenance. Wet-painted surfaces, by contrast, typically start showing wear within 2–5 years outdoors, particularly when exposed to UV light and moisture.
For items that see heavy use or are installed permanently outside — gates, railings, machinery, structural steel — that durability gap translates directly into cost savings over time.
Colour Range and Finish Quality
Both processes offer essentially unlimited colour options, including the full RAL and British Standard ranges for powder coating. However, powder coating typically achieves a more uniform finish with no brush marks, runs, or sags, even on complex shapes.
Powder coating also performs better on items with edges and recesses, because the electrostatic process pulls the coating into detail rather than pooling in corners the way liquid paint does.
Environmental Impact
Wet paints contain significant quantities of solvents — volatile organic compounds (VOCs) — which evaporate during drying and contribute to air pollution. Powder coating contains no solvents, and any overspray can typically be recovered and reused, making it a substantially cleaner process overall.
Cost
Wet painting has a lower upfront material cost, but when you factor in preparation time, the need for multiple coats, shorter maintenance cycles, and the labour involved in repainting, the total cost of ownership over 10–20 years typically favours powder coating.
So Which Should You Choose?
For most commercial work and for domestic items that live outdoors or see regular use, powder coating is the clear choice. Wet painting still has its place for very small or intricate items, indoor-only applications, or where a specific type of paint finish is specified.
If you’re unsure, a reputable coater will be happy to advise on the best approach for your specific project.