That's an excellent question! As someone who's specified and maintained countless park benches, I can tell you that a high-quality powder-coated finish is remarkably durable. Typically, you can expect a well-applied powder coat on a park bench to last anywhere from 10 to 20 years before it *needs* refinishing. However, that's a wide range because the actual lifespan depends heavily on several key factors.
First and foremost is environment. A bench in a mild, coastal climate will far outlast one in an area with harsh UV rays, extreme temperature swings, heavy industrial pollution, or constant exposure to de-icing salts. The quality of the initial application is critical; proper surface preparation (sandblasting) and a controlled, professional coating process are non-negotiable for longevity. Finally, the level of use and abuse matters. A bench in a high-traffic park will see more physical wear, scratches, and impacts than one in a quiet garden.
You'll know it's time to consider refinishing when you see significant fading of the color, chalking (a powdery residue on the surface), cracking, or peeling. Small chips or scratches can often be touched up, but widespread failure means the protective layer is compromised, and the steel underneath becomes vulnerable to rust.
To maximize the life of your powder-coated benches, implement simple maintenance: clean them once or twice a year with mild soap and water to remove dirt, pollutants, and organic matter. Avoid abrasive cleaners or tools. Inspect them periodically for any damage.
In short, while powder coating is one of the toughest finishes available for outdoor metal furniture, it's not immortal. With the right conditions and care, you can easily get 15+ years of service. When the finish shows signs of widespread failure, professional sandblasting and recoating will restore it to like-new condition for another long lifecycle.