Two terms that are often confused
The words rust and corrosion are often used interchangeably, but they don’t mean the same thing.
Both describe the deterioration of metal, yet they occur in different ways and on different materials.
In short: rust is a form of corrosion, but not all corrosion is rust.
What is corrosion?
Corrosion is the general process by which metal reacts with elements in its environment — such as oxygen, moisture or salts — causing surface damage or deeper decay.
It can appear as discolouration, pitting or flaking.
Corrosion can affect any type of metal, for example:
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Stainless steel may corrode when its chromium layer is damaged.
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Brass can darken or blacken through oxidation.
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Cast iron can develop surface corrosion that looks like rust, but isn’t always the same process.
What exactly is rust?
Rust is a specific form of corrosion that occurs only on iron or steel.
When these metals come into contact with moisture and oxygen, they form iron oxide – the familiar reddish-brown powdery layer.
Rust slowly penetrates the metal and can cause it to crumble if left untreated.
That’s why iron products are often finished with a protective lacquer or wax coating.
If that coating is scratched or worn, it’s important to repair it to prevent further oxidation.
Rust as a design feature
Not all rust is unwanted.
Many cast-iron products are intentionally given a light rust finish and then sealed with a clear lacquer to preserve the colour and texture.
This gives the metal a warm, natural look that suits country, rustic and industrial interiors.
Rust adds character — each piece develops its own tone and surface pattern, making every item unique.
A good example is the nostalgic cast-iron door handle set, available in a transparent rust finish.
The solid feel and aged look make it perfect for classic or industrial interiors.
For exterior use, the robust cast-iron door hook offers both utility and charm.
Its lacquered rust version combines durability with the rich, natural tone of aged metal.
Or consider the under-mount cast-iron hook – a rustic ceiling hook that shows how even small details can bring warmth and authenticity through a rust finish.
Rust is corrosion, but not all corrosion is rust
To sum up:
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Rust = oxidation of iron.
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Corrosion = deterioration of any metal.
Rust is instantly recognisable by its reddish colour and crumbly surface.
Corrosion, on the other hand, can appear grey, black or green depending on the metal.
Copper develops a green patina; brass darkens over time — both are forms of corrosion that many people actually appreciate for their aged character.
How to prevent rust and corrosion
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Keep metal dry – avoid long exposure to moisture.
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Repair damage quickly – reseal small scratches with wax or lacquer.
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Clean regularly – with a soft cloth and mild soap, never abrasives.
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Use beeswax, oil or clear lacquer depending on the material to maintain the protective layer.
In summary
Rust and corrosion are natural processes — part of what makes metal age beautifully.
With proper care, you can control them rather than fight them, keeping the authentic look and long life of materials like cast iron, wrought iron and brass.