How to Prepare Your Galvanised Steel Fence for Painting -  3 Proven Methods to Consider 

Painting a steel fence is not just about choosing the right fence paint or colour; it’s also about ensuring a clean and properly prepared surface for the paint to adhere to. Cleaning and preparing a galvanised steel fence is crucial to achieving a long-lasting and professional-looking finish. 

The reason is, galvanised steel poses a unique challenge when it comes to paint adhesion due to its inherent difficulty to bond with paint. So, our primary goal is to achieve a clean surface, devoid of grime, grease, or any contaminants that could hinder the adherence of paint to the galvanised steel. 

While we possess ample information about how to prep and paint timber fences, the intricacies of painting galvanised steel require even greater attention. 

The question is how to achieve a clean galvanised steel fence, ready to apply paint to. 

At Stock & Noble, we provide the finest fencing solutions to high-end property owners across Australia and New Zealand. Master Blend is our leading range of fence paints developed by experts with the sole aim to make your fences stay beautiful, for longer. We have years of experience and expertise in helping our clients create signature properties with gorgeous fences following the right methods and techniques. 

Through this blog, we will walk you through essential steps and pro tips for cleaning and preparing your galvanised steel fence before applying paint. In the end, you will have all the information needed to choose the right method to prepare your steel fences for paint and achieve fabulous-looking fences that last longer and save you time, money and effort. 

Why is it Critical to Clean Galvanised Steel Fence Before Painting? 

Cleaning galvanised steel before painting is a crucial step due to the unique challenges posed by this material. Proper cleaning is essential for a successful paint job, especially for black-painted steel fences that can become very hot when in direct sunlight for extended periods.  

Protective Oily Layer and Painting Complexity 

Galvanised steel arrives from the supplier with a protective oily layer on its surface. 

This oily layer adds complexity to the painting process, requiring thorough cleaning to ensure proper paint adhesion. 

Importance of Black-Painted Fences 

Like most Australian property owners, if you plan to paint your galvanised steel fence black, the need to achieve the best possible adhesion is higher. Black-painted fences face rigorous testing during high UV exposure days. As they can become extremely hot when in direct sunlight.  Like the temperature of a black car when been in the sun for a few hours. Inadequate clean-up can lead to poor paint adhesion, potentially causing paint cracking and peeling ultimately resulting in the need to start the painting process again to keep your fencing looking amazing.  

How to Clean a Galvanised Steel Fence Before Painting – 3 Options 

Option 1: Weathering and Manual Cleaning – Cheaper, but involves waiting 

One option is to let the steel fence weather naturally for up to 6 months. Sun and weather conditions can help remove the protective oily layer from the surface, naturally. After weathering, use hot soapy water and a scrubbing pad to manually clean each rail and post. 

While this method can be simple and effective, it has the downside of a prolonged waiting period and may not eliminate stubborn grease and oil residues. 

Option 2: Vinegar or Mineral Spirits – Simple, but has limitations

Consider using environmentally safe cleaning solutions like white vinegar. Vinegar’s acidic qualities remove the dirt and grime preparing the galvanised steel surface for an etch primer. Please note that there are two types of vinegar available: cleaning vinegar and standard white vinegar. The sole distinction between cleaning vinegar and distilled white vinegar lies in their acidity levels. Typically, white vinegar consists of 95% water and 5% acid. In contrast, cleaning vinegar boasts an acidity level of up to six%, making it approximately 20% more potent than regular white vinegar. 

While safe, natural and user-friendly, vinegar may not be the most effective solution. Mineral spirits, available at hardware stores, offer similar benefits to vinegar but would be regarded as a non-natural option and are generally expected to work better than vinegar. Both options don’t leave a residue and can help with the cleaning and preparation of galvanised steel.  

It’s worth noting that Mineral spirits cannot be used as a cleaner only as it may strip away some of the protective layers on the galvanised steel.  In simpler terms, if you use this cleaning option you should certainly paint over the top. So overall, Mineral Spirits can help with cleaning and preparation. However, they too might have limitations when it comes to highly effective cleaning of tough grease and stains. 

Option 3: Acetone – The Ultimate Cleaning Solution 

When it comes to effectively preparing your galvanised steel fence for painting, acetone emerges as the top-performing option. With its rapid and efficient cleaning properties, acetone can swiftly eliminate grime, grease, and contaminants from the steel surface. Acetone also dry’s extremely quickly which is helpful if you’re wanting to clean, prime and topcoat all in one day. 

However, it’s crucial to exercise caution when using acetone due to its volatile nature. It’s a hazardous chemical, and its application requires knowledge and precaution. 

To ensure safety, work in a well-ventilated area where vapours can disperse easily. Remember that acetone is a highly flammable chemical that has the potential to combust, so appropriate handling and storage are essential. Any rags/cloths used with the acetone should be carefully let dry as the low flashpoint of acetone can quickly combust causing a fire. Also, the tools and equipment should be carefully disposed of or packed away once the clean-up job is finished. 

Once cleaned with acetone, avoid touching the steel surface with bare hands, as even natural oils from your skin can affect primer adhesion. 

Choosing the Right Cleaning Method for Galvanised Steel Fence 

When deciding on the best approach to clean your galvanised steel fence, you have three viable methods to consider. 

Each method has its advantages and considerations, so it’s important to assess your specific situation before making a choice. 

The first two options provide a simpler application and clean-up process, making them ideal for those seeking a hassle-free experience who can afford to wait longer. They are suitable for most DIY projects 

On the other hand, acetone offers the fastest and the most effective clean-up. However, if you opt for acetone, take the time to familiarise yourself with the proper usage guidelines, including the do’s and don’ts to ensure a safe cleaning process. 

Know How to Prepare Your Galvanised Steel Fence for Painting? 

Preparing galvanised steel for painting requires a concerted effort, but the results are well worth it. Taking the time to thoroughly clean and prepare the surface ensures that the paint will adhere effectively and provide lasting results. 

Overall, acetone offers exceptional performance for thorough cleaning, but its use requires careful handling. Choose the cleaning method that best suits your needs, considering factors such as convenience and safety. Remember, properly cleaning your steel fence is only the first step. To ensure a flawless paint job, follow these additional steps on how to paint your steel fences. 

Given the challenges associated with preparing and painting galvanised steel, it’s essential to choose a high-quality steel fence paint that is specifically designed for this type of surface. Investing in a reliable and durable paint product guarantee that your efforts will pay off in the long run, with a finish that withstands the test of time and environmental factors. 

While proper cleaning and painting are essential for achieving a flawless finish on your galvanised steel fence, there are also convenient alternatives to consider. Pre-Powder-Coated Steel Post and Rail Fences offer a ready-made solution that saves you time and effort. Exploring these alternatives allows you to skip the cleaning and painting steps altogether, providing you with a beautiful low-maintenance fencing solution that still offers the benefits of galvanised steel’s strength, and longevity. 

To conclude, choose the right cleaning approach, follow the necessary steps, and select a quality steel fence paint to enjoy the best results and ensure your steel fence remains a durable and aesthetically pleasing asset for years to come. If you have more questions about painting galvanised steel fences or wish to explore the pre-powdered alternatives, book a complimentary consultation and receive personalised guidance from our fencing experts.