That's an excellent question! When comparing resin and metal outdoor trash cans, durability really depends on what specific challenges your trash can will face.
In my experience, modern resin trash cans have come a long way. High-density polyethylene (HDPE) resin is surprisingly tough. It won't rust, which is a huge advantage in rainy or coastal areas. I've had a resin can on my patio for five years through sun, snow, and rain, and it still looks and functions great. The color has faded slightly, but there's no corrosion. Resin is also lighter, so it's easier to move, and it doesn't dent like metal can. However, extreme cold can make some resins brittle.
Metal trash cans, typically galvanized steel or aluminum, feel more substantial. They're fantastic at resisting animal intrusions—raccoons have a harder time chewing through metal. They can handle very hot temperatures better than plastic. The main issue is rust. Even galvanized steel will eventually rust at seams or scratches. In humid climates, this can happen surprisingly fast. They're also noisier, heavier, and can get very hot in direct sun.
For pure longevity in harsh weather, a high-quality resin can often outlast a basic metal one because it ignores moisture. But if you need maximum strength and pest resistance, and you're willing to perform maintenance like touch-up painting, a well-made metal can be a lifelong purchase. For most homeowners seeking low-maintenance durability, a thick, UV-protected resin can is the more practical choice today.