How to fix a rusty grill: grates, body, and burners.

The single most important step is deciding what kind of rust you are dealing with. Run through this quick check before spending any time or money:

• Grates: Push on each bar. Solid bars with rust on the surface are a scrub job. Bars that flex, have visible pitting all the way through, or snap under pressure need to be replaced.
• Burner tubes: Look for rust holes in the side wall of the tube, not just the ports. Port blockage is a cleaning problem; holes in the tube wall mean gas escapes sideways. Tubes with wall holes need replacing.
• Exterior: Surface rust on the outside of the lid and firebox walls is cosmetic. The paint is gone, but the metal beneath is usually solid. Treat it with high-heat paint after scrubbing. Only rust-through holes in the firebox floor are a deal-breaker.

For surface rust, the four-step sequence is non-negotiable: soak, scrub, dry, season. Skipping any step means the rust returns fast.

1. Soak in 1:1 white vinegar and water for about an hour. The acid loosens rust without scrubbing. Keep it to an hour: vinegar keeps attacking the metal if you leave it overnight.
2. Scrub to bare, gray metal. A pumice grill stone, a bristle-free brush, or a wad of crumpled foil all work. Aim for clean cast iron with no orange-brown remaining. Rinse well.
3. Dry completely and immediately. Cast iron flash-rusts in minutes. Towel dry right after rinsing, then run the grill on low (or put the grate in a 200F oven) for 10 to 15 minutes to drive off moisture.
4. Re-season with a thin oil coat. Wipe a very thin layer of high-smoke-point oil (canola, grapeseed, or flaxseed) over the dry grate. Run the grill at about 400F for an hour. Let it cool and repeat one or two more times. Thin coats cure into a barrier; thick coats go gummy.

For the detailed cast-iron restore method, see how to restore cast iron grill grates.

Surface rust on the outside of a grill is a weathering problem. The paint has failed and the bare metal has started to corrode, but the steel below is usually solid. Treating it takes three moves:

1. Scrub the rusted area. Use a wire brush, steel wool, or an abrasive pad to remove loose rust and paint. You do not need to get to bare metal on every inch, just remove the loose and flaky material.
2. Apply high-heat paint. Use paint rated to at least 1200 degrees Fahrenheit for the exterior. Standard spray paint bubbles off within one or two cooks. VHT and Rustoleum both make dedicated high-heat grill paints in flat black. Light, even coats from about 12 inches away.
3. Cure the paint before cooking. Run the grill on low heat for 20 to 30 minutes with the lid open so the paint cures under real heat rather than peeling off on your first cook.

Surface rust on the outside of a burner tube is normal. What matters is whether the tube wall has rust-through holes.

If only the ports are clogged: With the grill cool and gas disconnected, remove the grates and heat plates. Inspect each port opening with a flashlight. Clear blocked ports with a stiff wire or paper clip from the outside. Do not enlarge them. This restores even flame without replacing anything.

If the tube wall has holes: Gas escapes through the holes sideways, starving the ports of flow. The symptom is weak, uneven flame that does not improve after cleaning. The fix is replacing the tube, not cleaning it. See the parts section below.