That's a great question! Keeping a metal trash can from rusting is all about creating a barrier between the steel and moisture. Here’s what I’ve found works best from years of dealing with outdoor bins.
First, start with a good cleaning. Empty the can and give it a thorough scrub with warm, soapy water to remove dirt, grime, and any early signs of rust. For tougher spots, a mix of vinegar and baking soda works wonders. The most crucial step? Let it dry completely in the sun. Any leftover moisture will trap under whatever protection you apply next.
Once it's bone-dry, inspect for any existing rust. Use a wire brush or sandpaper to scrub it off until you see bare metal. Now, apply your protective barrier. For a durable solution, spray on a rust-inhibiting primer, followed by a coat of exterior-grade paint. This creates a sealed, waterproof layer. For a simpler approach, a silicone-based lubricant spray (like WD-40) on the inside bottom and along seams can repel water effectively—just reapply every few months.
Prevention is key. Always use a liner bag to contain wet waste. Try to place the can in a shaded, covered area if possible, away from constant rain and sprinklers. If you're buying a new can, consider investing in a galvanized steel model, as the zinc coating provides excellent inherent rust resistance.
A little bit of maintenance once or twice a year makes a huge difference. A clean, dry, and protected can will last for many seasons, saving you money and hassle in the long run.