How Steel Fire Pits Patina and How to Care for Them

A patina steel fire pit is meant to change. It arrives a dusty rust orange, darkens toward a deep mahogany from the very first fire, and keeps deepening with use. Caring for it is mostly about leaving it alone at the right moments: no tarps while the finish matures, no wet leaves sitting on the steel, and a surface underneath that can live with a little weathering. Here is what to expect from carbon steel, weathering steel and stainless, and how to keep each one looking its best.

What a patina actually is

On a steel fire pit, the patina is a layer of iron oxide on the surface of the metal. On Fire Pit Art's carbon steel pieces, it is deliberate. The company says the steel is sandblasted down to bare metal and then treated so the pieces "mature and oxidize in a controlled, timely fashion". Each one ships with what Fire Pit Art calls a "dusty, powdery iron oxide patina or, rust" on the outside, and that finish is the starting point rather than the final color.

This is a finish you choose for its character. No two pieces age in exactly the same way, and Fire Pit Art is clear that small surface blemishes are expected from the material. If you want a finish that stays exactly as it looked on delivery day, a powder coat or stainless steel is the better fit, and both are covered below.

The first fires

The change starts immediately. Fire Pit Art describes it this way: "You'll see this patina change during the first fire changing from a rust color to a rich mahogany color." From there, the company says, the patina "will darken over time, with every burn" and then remain.

How fast depends on the fuel. Fire Pit Art notes that maturing takes longer on gas pits than on wood-burning pits. A gas pit gets there too; it simply takes more evenings.

While the finish is maturing, two habits matter most. Keep wet leaves and debris off the steel. Fire Pit Art's advice is to keep them off the piece until the steel matures, and to let it mature with each fire. And let the piece breathe, which brings us to covers.

Covers and tarps

Fire Pit Art is firm on this point: "Do not tarp your fire pit, the tarp will cause the patina to blacken and stop the oxidation process." Its patina guide explains that the oxidation process needs oxygen, which a tarp shuts out.

The patina is designed to live outdoors. Fire Pit Art describes it as maintenance free and says its pieces can be left outside in all weather, will "mature and darken a few shades and then remain permanent forever", and "will not rust through, rot, or warp over time."

Surfaces and staining

Iron oxide can travel. Architects who work with weathering steel note that its patina "may create unsightly stormwater runoff staining" on surfaces such as sidewalks, and the same common sense applies to any rust-finished steel sitting on light stone or concrete. Fire Pit Art's warranty does not cover discoloration or damage to a patio or deck surface, so plan the spot with that in mind.

• Choose a level, noncombustible surface. For wood-burning pieces this is not optional: Fire Pit Art says never to place a wood-burning fire pit on any wood surface.
• Darker stone, gravel or a paver field in warm tones hides weathering far better than pale limestone or white concrete.
• Think about where rain runs off the piece and where it drains. A low spot that holds water around the base will keep the steel wet longer.

Cleaning a steel fire pit

For routine cleaning, Fire Pit Art's advice for steel and copper fire pits is simple: hot soapy water and a soft cloth, a rinse, and to always dry immediately. On a wood-burning piece, clear out cold ash regularly so the bowl drains and does not hold damp ash against the steel. Our guide to spark screens, smoke and choosing firewood covers safe ash disposal.

Resist the urge to polish or strip a patina. It is the finish, not a stain on it, and Fire Pit Art offers no warranty on the iron oxide patina itself, so anything that removes it is a cosmetic decision you cannot undo. If a mark bothers you, send us a photo before you reach for a product.

Weathering steel, often called corten

Weathering steel is a different material from the mild carbon steel used on Fire Pit Art pieces, though the two can look similar once they have aged. Steel construction references describe weathering steels as high strength low alloy steels, with chromium, copper and nickel added, that give "an enhanced resistance to rusting" under normal outdoor conditions.

The protective patina on weathering steel develops under alternate wetting and drying, and it typically reaches its dark brown color within two to five years. The same references carry an important caution: in continuously wet or damp conditions, weathering steel corrodes at a rate similar to ordinary structural steel. A weathering steel fire feature wants a spot where it can dry out between rains, not a bed of damp mulch or a corner that never sees the sun.

Salt air and the coast

Salt is the one condition steel patinas do not handle well. Guidance on weathering steel is direct: exposure to chloride from sea spray, salt fog or coastal airborne salt "is detrimental", because salt keeps the surface continuously damp. Fire Pit Art excludes saltwater environments from its warranty, which covers both carbon steel and stainless steel pieces.

If your home is on the coast, talk with us before choosing a steel piece. Our guide to fire features for lake and coastal homes looks at materials that suit waterfront settings, and concrete, GFRC, copper, corten, steel and stone compared puts steel alongside the other options.

Powder coat and stainless steel

If you love the art but not the idea of an evolving finish, Fire Pit Art offers powder coat colors at additional cost, with the natural iron oxide patina included at no extra cost. Its shipping and returns page notes that there is no warranty on oxide patina or painted finishes, and powder-coated pieces are non-refundable once paid, so decide on the finish carefully before ordering.

The Bella Vita series is built from quarter inch 304 stainless steel with a matte bowl and polished base. Fire Pit Art lists a 100 year warranty on stainless steel fire pits for structural integrity, and notes that stainless steel does require periodic cleaning to maintain its finish. Carbon steel pieces carry a 10 year manufacturer's warranty. The Bella Vita pages describe the stainless guarantee in broader terms than the warranty page does, so the warranty paperwork that ships with your piece is the document to keep.

Pieces to consider

These show the finishes side by side: patina carbon steel in several forms, a lidded piece that doubles as a table, and the stainless Bella Vita.

For how these pieces are made and how to choose a design, read art steel fire pits: a guide to handcrafted wood burners.

Common questions

Why did my steel fire pit change color after the first fire?

That is the patina doing what it was designed to do. Fire Pit Art ships its carbon steel pieces with a rust-colored iron oxide finish and says it changes during the first fire from a rust color to a rich mahogany. It keeps darkening with each burn before settling. Fire Pit Art says the change takes longer on gas pits than on wood-burning ones. It is not a defect and needs no treatment.

Can I cover my patina steel fire pit?

Check with us first. Fire Pit Art says not to tarp its fire pits, because a tarp causes the patina to blacken and stops the oxidation process, yet it also sells its own canvas covers for some models. Leave the piece open to air and keep wet leaves off it while it matures. Before you use any cover, ask us and we will check with the manufacturer.

Will a patina steel fire pit rust through?

Fire Pit Art says its pieces "will not rust through, rot, or warp over time" and backs its carbon steel fire pits with a 10 year manufacturer's warranty. The patina finish itself is not covered by the warranty, and saltwater environments are excluded. Keep the bowl draining freely, clear out damp ash, and avoid spots where water pools around the base.

Is a steel fire pit a good choice near the ocean?

Usually not. Salt keeps steel surfaces damp, and weathering steel guidance calls exposure to sea spray and coastal airborne salt detrimental to the patina. Fire Pit Art excludes saltwater environments from its warranty on both carbon steel and stainless steel pieces. For a coastal home, talk with us about materials better suited to salt air before you choose.

Sources

1. Fire Pit Art, The Patina Process, first fire, do not tarp, oxidation needs oxygen, will not rust through
2. Fire Pit Art, Iron Oxide Patina Color: Before and After, rust color to rich mahogany
3. Fire Pit Art, The Rings of Warmth (Saturn), controlled oxidation, darkens with every burn
4. Fire Pit Art, Saturn, dusty iron oxide patina on delivery, do not tarp, wet leaves and debris
5. Fire Pit Art, Low Boy, maintenance free, all weather, remains permanent
6. Fire Pit Art, Magnum, sandblasted to bare steel, powder coat option
7. Fire Pit Art, Finish Disclaimer, small surface blemishes expected
8. Fire Pit Art, How To Properly Clean Any Cast Iron, Steel, Brick, or Copper Fire Pits
9. Fire Pit Art, The Ageless Beauty of a Natural Patina Steel Fire Pit, stainless steel requires periodic cleaning
10. Fire Pit Art, Warranty, carbon and stainless terms, patina and saltwater exclusions, surface discoloration exclusion
11. Fire Pit Art, Shipping and Returns, no warranty on oxide patina or painted finishes, powder coat non-refundable
12. Fire Pit Art, Delivery Method, do not place a wood-burning fire pit on any wood surface
13. Fire Pit Art, Bella Vita, 304 stainless steel, guarantee wording
14. SteelConstruction.info, Weathering steel, alloying elements, wet and dry cycles, two to five years, continuously wet conditions
15. New Steel Construction (BCSA and SCI), Atmospheric corrosivity classifications for weathering steel, chlorides detrimental
16. Metal Architecture, Weathering Steels Offer Distinct Elements of Design, runoff staining