Rust on a grill almost always starts the same way: moisture sitting on bare metal, usually because a protective seasoning layer wore off or a grill sat uncovered through rain. Caught early, it's a straightforward fix. Left alone, it eats through grates and burner tubes.

Surface rust vs. structural rust

Surface rust looks flaky or powdery and sits on top of otherwise solid metal — you can usually scrape it off with a fingernail. Structural rust has pitted or thinned the metal itself; you'll see rough, crumbly texture, and in bad cases, actual holes. Surface rust is a cleaning job. Structural rust on a burner tube is a safety issue — replace the part rather than trying to clean through it.

Removing surface rust from grates

  1. Dry scrub first. A stainless steel brush or coarse steel wool removes loose, flaky rust without introducing more moisture.
  2. For stubborn spots, use a paste. Baking soda and water, or a 50/50 vinegar-and-water soak for 10–15 minutes, loosens rust that won't come off dry.
  3. Rinse and dry completely. Any leftover moisture restarts the rust process immediately — dry with a towel, then let the grill run on high for 10 minutes to fully evaporate any remaining water.
  4. Re-season cast iron grates. A thin coat of high-smoke-point oil, baked on at high heat, rebuilds the protective layer that prevents future rust — see our seasoning guide for the full process.

Rust on burners and the firebox

Light surface rust on the firebox floor or lid interior can be treated the same way as grates. Rust on burner tubes is more serious — a rusted-through burner can create uneven gas flow or, in rare cases, a leak at the rust point. If you see rust holes on a burner (not just surface rust), replace the burner rather than attempting a clean-and-patch fix.

When to call it: if more than half a burner tube is rusted through, or the firebox floor has thin spots you can flex with hand pressure, it's time to weigh repair cost against a replacement grill.

Preventing rust from coming back

  • Use a properly sized weatherproof grill cover when not in use.
  • Run the grill on high for a few minutes after cleaning to fully dry the interior before closing the lid.
  • Re-season cast iron grates a few times a season, not just after a deep clean.
  • Don't store a grill directly on soil or grass — moisture wicks up from underneath even with a cover on top.

Let us handle the rust removal

Our Premium Restoration tier includes rust treatment and re-seasoning — mobile service across Merced and the Central Valley.

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