Keeping a Fire Pit From Rusting

Why Fire Pits Rust

Two things strip a steel fire pit of its protection: heat and weather. A chiminea and fire bowl supplier explains that the heat-resistant paint on cast iron and steel is not fireproof; when a hot fire burns it off, the surface rusts. The same supplier says steel and cast iron left outside rust very quickly, and that steel bowls in particular are made of fairly thin material.

So some rust is part of owning a steel fire pit. That supplier tells buyers to expect it: paint discolors and flakes after firing, and the metal parts will rust. The goal is to keep it on the surface, not let it eat through the bowl.

Where the pit sits makes a difference too. A bowl set straight on grass or soil stays damp underneath, while one on a stand, on pavers or on gravel dries out between storms.

Ash and Standing Water

A bowl full of old ash holds water after every storm and keeps the steel wet for days. Emptying cold ash every few fires, as one fire pit maker recommends for airflow anyway, also lets the bowl dry out after rain.

Standing water is the other half. A pit without a drain hole fills in a summer downpour; a gas pit's burner pan relies on weep holes that dust from the media can plug. One gas fire pit maker's fix for water in the pit is to remove the media, unplug the weep holes and make sure the enclosure drains. Our guide to air and drain holes in a fire pit covers where those holes belong.

Covers, Used the Right Way

Both the gas fire pit maker and the chiminea supplier recommend a cover. The gas fire pit manual highly recommends covering fire features when they are not in use, and the chiminea supplier recommends one for every metal model. The detail that matters is timing:

• Cover the pit only once it is completely cold.
• Put the cover on a dry pit; a cover over a wet bowl holds the water in.
• Let air reach underneath, so a muggy night does not condense inside a sealed bag.
• Take the cover off before lighting; the gas fire pit maker warns that leaving a combustible cover on is a severe safety hazard.

Paint and Coatings That Survive Heat

Ordinary paint does not belong on a fire pit. The chiminea supplier specifies heat-resisting stove paint for cast iron and steel, and rates its own heat-resistant finish to 600 degrees Celsius while warning that no paint is truly fireproof. Wire-brush loose rust off first, then repaint the bare spots once the pit is cold and dry.

Metal parts outside the fire get the same treatment. One outdoor fireplace maker tells owners to paint the termination cap on top of the chimney with a rust-resistant paint to protect it from corrosion.

Stainless, Cast Iron and Weathering Steel

The metal you start with decides how much work rust takes. One fire pit maker offers 304 stainless steel and Corten weathering steel, and explains that Corten is designed to form a weathered iron oxide layer that protects it from the elements, so its orange color is the finish, not a failure. Stainless parts in a gas pit can turn golden or brown with heat, which the gas fire pit manual calls normal.

Cast iron, the chiminea supplier says, lasts longest of the three common materials but still rusts when rain gets at it or the paint burns off. Thin painted steel is the one that needs the most care.

When Rust Has Gone Too Far

A bowl rusted through, a liner ring flaking apart or a gas burner pan with holes eaten into it is past paint. A rusted ring in a block pit can be replaced on its own, and a gas pan is a part for our outdoor fireplace technicians to swap after a free inspection and a written estimate.

Ours is a locally owned family company with experienced hands on every job. We are Proudly American and plain about it, and the Proudly American crew will tell you when a thin steel bowl is simply worn out.