how to stop metal from rusting

Rust forms when ferrous metals such as steel and iron react with oxygen and moisture, creating iron oxide. Outdoor exposure accelerates rust, especially in the UK, as humidity levels are consistently high. The Met Office reports that several UK regions, especially on the coast and in the west, often have monthly humidity levels exceeding 80%. This persistent moisture creates ideal conditions for the formation of iron oxide.

Knowing how to stop metal from rusting is vital for anyone dealing with outdoor gates, frames, or structural pieces. Rust weakens surfaces, reduces durability, and increases long-term maintenance costs.

Prevention is achievable through:

This guide outlines the causes of rust and effective prevention methods. We also examine how cut-to-size metals can offer long-term durability.

What Causes Rust in Outdoor Metal Structures

Rust forms when iron in metals reacts with oxygen and water. The combination triggers an electrochemical process that gradually breaks down the surface.

In outdoor environments, several factors increase the risk:

  • Continuous wetting from rainfall or condensation enables iron oxide to accumulate over time.
  • Salt carried by coastal air significantly accelerates corrosion. A report from the Energy Networks Association says that electrical infrastructure by the sea wears out more quickly. Airborne salt is a significant issue, particularly for mild steel parts, and is well-known in the coastal areas of the UK.
  • Urban air pollution leads to corrosion. It occurs when pollutants combine with moisture, creating acidic deposits. This is evident in the Department for Environment, Food & Rural Affairs (DEFRA) Air Pollution in the UK report. It explains that nitrogen oxides and sulphur dioxide, often found in cities, react with water. This reaction creates corrosive compounds that land on exposed surfaces, including metal.
  • Scratches, welds, or unsealed edges expose bare steel, creating weak points where rust develops quickly.
  • Poor ventilation can trap humidity, creating microclimates that accelerate the growth of rust. The Health and Safety Executive’s (HSE) ventilation guidance stresses the need for good airflow in enclosed spaces. This is vital to prevent moisture build-up, which is a significant cause of localised corrosion.

In practice, untreated mild steel used for outdoor structures is highly susceptible to corrosion. It’s crucial to consider these risks while designing and installing. Doing so will help enhance durability and performance.

Choose the Right Metal to Avoid Rust

The most effective way to stop metal from rusting is to select corrosion-resistant materials at the outset. Choosing the right material is crucial for outdoor items such as gates, signs, frames, and decorative features. Several metals offer long-term protection against rust or other forms of corrosion.

Galvanised Steel

Galvanised steel is created by applying a zinc coating to steel, forming a barrier against oxygen and moisture. The zinc also provides cathodic protection, meaning it corrodes in place of the steel, thereby protecting it from corrosion. This makes galvanised steel ideal for outdoor frames, fencing, and support structures. Its strength and durability are essential for these uses. Explore our range of galvanised steel, cut to size for direct installation.

Stainless Steel

Stainless steel contains chromium, which reacts with oxygen to form a thin, protective chromium oxide layer. This layer repairs itself if it gets damaged. It provides stainless steel with outstanding rust resistance, even in harsh conditions. It works well for decorative panels, structural brackets, and outdoor fixtures. Both strength and appearance are important here. Explore our stainless steel products for a range of versatile grades and finishes.

Aluminium

Aluminium does not rust because it contains no iron. Instead, it develops a protective aluminium oxide surface that resists corrosion. Its low weight makes it well-suited to signage, cladding, and garden features. In coastal or industrial areas, extra protective finishes can help extend service life. Discover our aluminium range, supplied cut to your exact requirements.

Brass

Brass, an alloy of copper and zinc, does not rust because it contains no iron. Instead, it may develop a natural surface tarnish known as patina. Brass is prized for its strength, corrosion resistance, and gold-like look. This makes it great for decorative fittings, architectural details, and marine uses. Browse our brass products for use in both functional and decorative projects.

Mild Steel

Mild steel is popular for construction and fabrication because it’s strong and affordable. However, it can rust easily without protection. When used outdoors, mild steel must be treated with coatings or galvanisation to prevent rapid corrosion. Learn more about our mild steel options and processing services to ensure suitability for external use.

Three Essential Maintenance Habits

Even with corrosion-resistant metals and coatings, regular maintenance is needed for long-term performance. A consistent programme reduces the risk of deterioration and avoids costly repairs.

1. Routine Cleaning

Dirt, leaf litter, and debris can trap moisture against the surface of metals. Over time, this creates conditions that facilitate the development of rust more easily. Damp build-up in sheltered areas promotes localised corrosion. The HSE’s guidance on corrosion says that stagnant moisture can cause pitting and crevice corrosion. This is especially true in areas with poor drainage or airflow. Here, these types of corrosion can develop faster than regular surface rust.

2. Scheduled Inspection & Resealing

Joints, welds, and cut edges should be checked as part of a scheduled inspection programme. For commercial or public settings, inspections should form part of standard asset management. Where coatings show signs of wear, reapplication of primer or paint is essential to restore protection.

3. Avoiding Galvanic Corrosion

When two dissimilar metals come into contact in the presence of moisture, one will corrode faster. This process is known as galvanic corrosion. You can stop this by insulating connections or designing structures to keep metals from touching each other directly.

By adopting these maintenance practices, outdoor structures retain strength and appearance for longer. Our delivery service guarantees that materials arrive ready for installation. This reduces on-site handling and helps prevent unnecessary damage to surfaces.

Protect Your Project from Rust

To prevent metal from rusting outside, you need the right materials, protective coatings, and regular upkeep. With these measures in place, structures can remain durable and reliable even under the UK’s demanding climate.

Clickmetal offers a complete range of cut-to-size metals. This includes galvanised steel, stainless steel, aluminium, brass, and mild steel. With over 70 years of experience, we prepare every order in-house. Our ISO-accredited processes ensure precise, nationwide delivery.

Whether you’re using large frameworks or small decorative pieces, our metals provide you with the strength and durability you need. They also resist corrosion for years to come.

Call 01794 526090 or order your cut-to-size metals and ensure your next project is built to last.