How Galvanic Corrosion Affects Aluminium Fencing in Perth?
Aluminium fencing is a popular choice across Perth due to its durability, design and resistance to corrosion. However, its lifespan can be reduced when incompatible metals like steel screws or brackets are used during installation. Understanding galvanic corrosion and how professionals prevent it helps to ensure fencing systems stay attractive and long-lasting. Read on to know more.
What Is Galvanic Corrosion?
Galvanic corrosion is an electrochemical reaction that occurs when two dissimilar metals come into electrical contact in the presence of an electrolyte such as moisture or salt deposits. One metal becomes the anode and corrodes rapidly, while the other acts as the cathode and stays well.
Although aluminium naturally develops a thin oxide layer that provides corrosion resistance, direct contact with noble metals under suitable environmental conditions can gradually break down this protective barrier. In the coastal suburbs of Perth, high humidity levels and airborne salt increase the likelihood of galvanic corrosion.
How Incompatible Metals Affect Aluminium Fencing?
Many fencing systems include additional hardware beyond the aluminium panels themselves. Problems arise when components made from different metals are installed together without proper isolation. Examples include:
• Mild steel screws
• Carbon steel brackets
• Galvanised fasteners with damaged protective coatings
• Untreated steel mounting plates
• Mixed-metal gate hardware
When moisture bridges these metals, electrons transfer between them. Aluminium, being the less noble metal, gradually sacrifices itself. This leads to localised corrosion around fixing points. The damage starts beneath washers or around screw heads, making it difficult to detect until visible staining appears. This is a common concern for anyone maintaining Fencing in Perth, particularly in properties exposed to coastal air.
Signs That Galvanic Corrosion Has Started
Early identification always prevents extensive repairs. Look out for signs like:
• White powdery aluminium oxide deposits
• Pitting around screws or brackets
• Bubbling or lifting powder-coated finishes
• Discolouring near fasteners
• Loose connections caused by metal loss
• Cracking around fixing points
These symptoms initially appear cosmetic, but they eventually reduce the structural integrity of aluminium fences.If you notice any of these warning signs, our guide on fencing repair professionals in Perth and when to call them explains the next steps before the damage spreads further.
How Professionals Prevent Galvanic Corrosion?
Experienced fencing installers use several engineering practises to reduce galvanic corrosion throughout the fence’s service life. These are:
1. Selecting Compatible Fasteners
Marine-grade stainless steel fasteners are preferred, particularly grades suited for Australian outdoor environments. This is because they provide excellent corrosion resistance when matched with aluminium components. Installers also avoid mixing multiple metal types unnecessarily throughout the system.
2. Electrically Isolating Different Metals
When different metals must be used, professionals install non-conductive nylon washers, plastic
spacers, rubber gaskets, or insulating sleeves to prevent direct electrical contact. Breaking the electrical circuit greatly reduces galvanic activity.
3. Protective Surface Coatings
Powder coating is an essential barrier against moisture. However, drilled holes, scratches, and installation damage can expose the aluminium. Professional installers seal penetrations where appropriate and minimise coating damage during installation to stop corrosion.
Considering Perth’s Environmental Conditions
Properties near Perth’s coastline demand higher-grade stainless steel hardware, enhanced powder coating systems, and stricter fastener selection than inland installations. Recent Australian construction practices also place a great emphasis on durability-based material compatibility. This is true especially for outdoor architectural products exposed to marine environments.
Galvanic corrosion is a preventable issue that significantly affects the longevity of aluminium fencing systems when compatible metals aren’t used together. Careful material selection, high-quality protective coatings and professional installation techniques all contribute to long-term durability.
All Perth Fencing is a licensed contractor serving the Perth metropolitan area. We specialise in installing and repairing aluminium and Colorbond fences. Our fencing contractors are certified to handle all types of aluminium and Colorbond fencing systems. Stay tuned to our blog page for more information.