The lifespan of anti-corrosion coatings is determined by the type of coating it is, the application and the environment they are in.
In this blog, we go over ways to ensure optimal performance and signs to look out for that coatings require maintenance.
Continue reading to find out how to make the most out of anti-corrosion coatings.
What Are Anti-Corrosion Coatings
Anti-corrosion, or anti-rust, coatings are a spraying solution for metal components. It works to protect against the degradation of the component’s surface qualities, which occurs due to moisture, salt spray, or oxidisation.
By creating a physical barrier isolating the surface layer of a substrate, it is protected against environmental impacts. Anti-corrosion coatings also offer chemical protection against rusting.
There are three main types of anti-corrosion coatings:
Sacrificial: Applied in thin metal layers that have a lower electrode potential value.
- The type of paint binder and additive content used determines the strength of corrosion protection.
- Unlike barrier coatings, sacrificial coatings remain effective if damaged or worn.
- To protect the component underneath, these coatings work as an additive, sacrificially corroding.
Inhibitive: A chemical compound added to liquid or gas that reduces the rate of corrosion when in contact with a metal.
- The porous coating forms a passive layer over the substrate.
- Frequently used in primers that are overcoated.
- When penetrated, the coating reacts with humidity and metal.
Barrier: A protective, non-porous layer that when applied to a substrate prevents environmental elements from affecting the base metal.
- If the barrier underneath is worn or damaged, the substrate is unprotected.
- Additional coatings are usually required to protect the barrier.
- The lifespan of the protective layer is significantly impacted by film thickness and solid content.
Typical Lifespan Of Anti-Corrosion Coatings
The lifespan of anti-corrosion coatings can differ depending on the type of coating, the environment in which it is used, the surface preparation for coating, quality of application and maintenance.
Sacrificial Coatings Lifespan
- Zinc-Rich Coatings – 10 to 25 years. Lifespan is impacted by the mildness or extremity of the environment. Zinc-rich coatings are most effective in steel structures.
- Aluminium Coatings- 15 to 15 years. Used on aluminium substrates, typically found in marine structures.
- Magnesium Coatings- 5 to 10 years. Its high reactivity means it is desired for applications where rapid corrosion of the application enhances the protection of the substrate.
Inhibitive Coatings Lifespan
- Chromate Coatings- 5 to 20 years. Commonly used for aluminium and steel. The lifespan is dependent on the aggressiveness of their environment.
- Phosphate Coatings- 3 to 10 years. Typically used in undemanding environments as a base for painting or a standalone protective layer.
- Organic Inhibitive Coatings- 5 to 15 years. Can be combined with other coating types in the paint matrix for optimal protection.
Barrier Coatings Lifespan
- Epoxy Coatings- 10 to 20 years. Known for their superior adhesion and chemical resistance. Often utilised in marine and industrial structures.
- Polyurethane Coatings- 5 to 15 years. Because of its resistance to UV radiation and flexibility, it can be used in automotive, aerospace, and outdoor applications. Lifespan will be affected by levels of sun exposure.
- Acrylic Coatings- 5 to 10 years. Qualities include easy application, strong weather resistance and fast drying, so are often used for architectural and decorative applications.
- Vinyl Coatings- 8 to 15 years. Provides strong resistance to water and chemicals.
Factors Affecting The Lifespan Of Anti-Corrosion Coatings
As you will have seen, the lifespan of anti-corrosion coatings can range over 10 or even 20 years. There are a range of factors that impact the durability and lifespan of anti-corrosion coatings.
We’ve already alluded to what some of those factors are, but allow us to go into more detail…
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Environmental Conditions
- Exceedingly high levels of humidity or moisture can quicken the wear of anti-corrosion coatings.
- At either extremity, high or low, temperature can cause thermal extraction or contraction, which leads to the cracking or peeling of coatings.
- In marine settings, high salt concentrations can increase corrosion rates and therefore affect the lifespan and effectiveness of coatings.
- Highly acidic conditions or heavily polluted environments can accelerate the process of corrosion.
2. Quality Of Surface Pre-Application
- Cleaning the surface of the substrate before application will give optimal results. Any contaminants remaining on the surface, like dirt, grease, oil, or rust, will prevent successful adhesion.
- Ensuring the surface of the substrate is smooth by either sandblasting or shotblasting will help maintain its lifespan.
3. Method Of Application
- Different coating types require different methods of application, such as brush, spray or dip. The application method must align and be suitable with the coating method used.
- When coatings are applied, the environmental conditions must be controlled and regulated, so it has time to set.
- Ensuring adequate thickness will impact the efficiency of the coating.
4. Type Of Coating
- Choosing the right coating application for optimal performance in a specific environment is crucial for its durability.
- Choosing coating solutions from a reputable manufacturer will determine its quality and lifespan.
Signs That Anti-Corrosion Coatings Need Maintenance
Due to the number of variables that can alter the lifespan of anti-corrosion coatings, it can be hard to determine when the coatings require maintenance. There are a few telling signs that anti-corrosion coatings require maintenance or replacement.
Visual indicators are an easy sign to look out for. This could include cracking, blistering, peeling, discolouration, or chalking of the coating.
Performance indicators, such as a noticeable reduction of shine on the coating, rust spots or thinning, could mean the protective barrier has been compromised.
Physical indicators may occur due to ageing, chemical degradation or environmental exposure. If the anti-corrosion coating begins to soften, become brittle, or swell, then it requires maintenance.
Functional indicators are potentially more threatening, as this could mean the substrate itself has deteriorated. Increased corrosion rates or adhesion loss indicate that the coatings must be replaced.
Anti-Corrosion Coatings From Alphatek
Choosing compatible coating material, proper application, and observing its wear will impact the lifespan of anti-corrosion coatings.
Customers of Alphatek depend on our quality coatings to boost their profitability, enhance production and decrease downtime. All while cutting their costs and wastage.
Our Corrosion Protection Coatings are the solution to the current degradation issues you are facing. We will provide any relevant maintenance advice, so you can be assured our product provides maximum results.
If you’re interested in working with us, get in touch today. You can email us at postbox@alphatek.co.uk or give us a call at +44 (0) 1706 821021.
