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How to Remove Rust on Galvanized Steel?
If you are concerned about rust, you can use rust-resistant metal like stainless steel, but it can be costly. Alternatively, you can coat a metal that does rust with galvanization, which involves applying a zinc coating over steel to prevent rust and corrosion for 50 years or more. However, eventually, rust can still develop.
Why and how to remove it? Let’s keep reading to find out.
Basics of Galvanized Steel
Galvanized steel is a type of steel treated with a protective zinc coating through a hot-dip galvanizing process.This coating provides excellent corrosion resistance and longevity, making it suitable for outdoor structures, marine environments, and industrial equipment.
Why Galvanizing Can Prevent Rust
Corrosion is the breakdown of metal when oxygen attacks its surface. Rust is a type of corrosion experienced by iron. Unlike iron, aluminum and stainless steel do not rust. Instead, they develop a protective oxide layer that resists further corrosion.
Zinc is a barrier against oxygen and water penetration to the underlying steel. Initially, it forms a zinc oxide layer on the surface, which subsequently transforms into zinc carbonate in the presence of moisture. This transformation results in a dull gray patina that is insoluble in water, effectively preventing further chemical reactions on the metal surface
Does Galvanized Steel Rust
Galvanized steel is highly resistant to rust due to its chemical properties. However, galvanized steel can rust if the zinc coating is not intact. As long as the zinc coating remains undamaged and provides sufficient coverage, the steel underneath is protected from rust. However, if the zinc coating is compromised, the steel may become vulnerable to rust. In such cases, it may be necessary to remove them, followed by applying a new layer for protection.
Factors Influencing Rust on Galvanized Steel
The corrosion resistance of galvanized steel depends on various factors. More thicknesses of zinc coatings provide heightened protection against rust. However, exposure to corrosive environments, particularly in coastal areas, may accelerate the onset of rust. Additionally, relative humidity, mechanical damage, and moisture exposure can all impact the longevity of the zinc coating, consequently influencing the steel’s resistance to corrosion.
Impact of Local Conditions
When considering the use of galvanized steel, it’s essential to consider the local conditions. Specifically, consider the following:
1. Temperature: At temperatures below 420°C, zinc remains resistant to deterioration; however, elevated temperatures, humidity, and industrial contaminants can accelerate the corrosion process. Conversely, low temperatures do not impact the integrity of galvanized coatings.
2. Air: Exposure to high or low humidity, salt, or acids can impact galvanized steel.
3. Soil: When galvanized steel is buried in the earth, its exposure to moisture will depend on soil conditions. Wet conditions will have a worse effect than dry conditions.
How to Maintain Galvanized Steel
Cleaning
Ensure that galvanized steel surfaces are periodically cleaned to eliminate dirt, debris, and contaminants. The best way to do this is to use mild detergent and water. Gently scrub the surface with a soft-bristle brush or cloth, partcularly areas with accumulated grime. Thoroughly rinse with clean water and use a clean cloth to dry the steel to prevent water spots. Regular cleaning helps prevent the formation of corrosive substances on the surface and maintains the integrity of the zinc coating.
Maintenance
Treat any rust spots promptly using a rust converter. Then, follow with a zinc-rich primer and topcoat to protect the steel. This periodic maintenance prevents further corrosion and maintains galvanized steel’s effectiveness over time.
Avoiding Sandblasting
When cleaning galvanized steel, avoid sandblasting as it can scratch the zinc coating and compromise its protective properties. Use gentle materials and mild cleaning solutions instead. Be cautious with power washers, as excessive pressure can harm the coating, During cleaning and maintenance, gentle care will help preserve the steel’s durability and effectiveness.
Inspection
Inspections are crucial to identify early signs of corrosion, especially in areas where the zinc coating may be compromised.
Be thorough in inspecting areas where the zinc coating might be compromised, such as due to scratches.
Your One-Stop Shop for Galvanized Steel
Enze is proud to offer galvanized steel parts and surface finishing services for your next project. With 20 years of experience in galvanizing, we have established ourselves as industry experts.
