Will Galvanized Steel Rust after Welding?

Metal sheet steel has always been one of the major minerals for construction due to its long-lasting nature.  However, there is always a need for durability in the construction world. I often wonder if galvanized steel rust after welding since galvanization is a big trend.

After welding, a galvanized metal steel sheet is still susceptible to rust and corrosion. Therefore, before the metal can be welded, the galvanized zinc coating on it would be removed, giving way to corrosion. This is a common problem that one comes across when dealing with welding metals. 

If welding is not done properly, it can cause galvanized steel to rust or be corroded. Here, I’ll explain what Galvanized steel means, why it is important, and how durable it is.

What Is Galvanized Steel?

The usage of steel can be traced back to the industrial era. However, even long before the industrial era, blacksmiths made a living from smelting various forms of metals. 

But in the end, you would discover that metals usually lose their quality and start to deteriorate. This loss of quality is due to various conditions such as moisture and oxygen, a preventive method called Galvanizing was invented. But is galvanizing steel a lasting solution, or will it galvanize steel rust after welding? 

As we all know, steel is one of the hardest and strongest minerals. However, being the strongest doesn’t mean it would last forever; rather, it gives temporary immunity to external forces. Galvanization was introduced to help metal sheet steel last longer than ordinary steel. 

Galvanized steel is a type of steel galvanized through zinc coating on said steel. This process protects the steel from corrosion or rust. In short, galvanized steel has a longer life span and is more durable than ordinary steel. 

The process of applying zinc on steel “galvanized” was invented in England and France in the year 1837.  Inventors discovered that a sheet of steel could be dipped into a molten zinc bath called “hot dip galvanization.” This is a process of dipping steel into a molten zinc bath and bonding the zinc and sheet together. 

The extra zinc layer over steel acts as a protective guard for the steel to prevent corrosion or rust. Hot-dip galvanization is the most common method of applying a zinc coating over steel; however, there are other processes. I would list out the various forms of galvanizing steel below. 

Hot-dip Galvanization

The first method of galvanization that I’ll discuss is the “Hot-dip Galvanization.” This method is one in which a steel sheet is dipped into a bath of molten zinc. Once this is done, it is kept at a temperature of 860°F (460°C). When this process occurs, the steel comes into contact with this molten zinc. 

An iron zinc alloy is formed during this process, and the steel sheet is taken out in a normal atmosphere. Zinc oxide is formed during this process; this oxide is the one that prevents rust and corrosion.

Mechanical Plating 

Another form of Galvanization is Mechanical plating. This process is one where zinc powder, glass beads and other forms of special reducing agent are coated on the steel sheet. This reducing agent helps to bond zinc particles on the surface of the sheet, thereby reducing or preventing corrosion and rust. 

Zinc electroplating

Zinc electroplating is also another form that increases the lifespan of metal sheet steel. This is a method where a steel sheet is dipped into zinc solution, and an electric current is passed through it. The electric current helps to spread the zinc ion solution uniformly on the metal sheet.

Zinc metal spray

Zinc metal spray is a method where a steel sheet is cleaned to Class level III. Once that is done, zinc in the form of a powder is sprayed on top of it. Most times, one would need the aid of a plasma flame gun to achieve this goal.


The steel sheet is heated up to a temperature of 752°F (400°C), and the heated sheet passes through zinc powder. At this high temperature, diffusion between zinc and steel molecules occurs.

Galvanized Wire and Continuous Strip Galvanization

A steel strip or steel wire is passed through a molten zinc solution with this process. This process is usually done at a high speed of 590 feet, “180 meters” per minute in a controlled air pumping environment. In addition, this method applies a zinc coating on the metal sheet, thereby protecting it from corrosion. 

Why Galvanize?

Galvanized Steel is a steel that has gone through the application of protective zinc coating. This coating helps to prevent premature corrosion and rust. As a result, those who use galvanized steel for construction tend to spend less on maintenance and repair than those who use ordinary steel.

 And this advantage is a result of the properties of galvanized steel. Without proper protection, metal steel will rust due to various atmospheric conditions. Over time, the degree of rust will depend on the environment and the product’s state. 

Rust is a form of iron oxide, “typically a red oxide.” Rust is formed by the oxidation and reduction of oxygen and iron in the presence of air, moisture or water. 

Considering the effectiveness of galvanized metal sheets, I’ve outlined some beneficial reasons as to why steel should be galvanized. 

  • Longevity: Galvanized Steel is said to last longer than normal steel. This fact alone is something that everyone looks out for when they purchase any product. 
  • Durability: Galvanized metal steel sheets are more durable than ordinary steel sheets. This is another factor people would prefer when comparing ordinary steel and galvanized steel sheets.
  • Reduced future expenses: After we acquire any ungalvanized steel product, we realize that we end up spending extra costs on maintenance and repairs in the long run. Therefore, galvanization sees that the amount spent on repairs and maintenance is drastically reduced. 
  • Reliable: Galvanized Steel is more reliable due to the extra coating of zinc that acts as a protective agent against rust and corrosion. On the other hand, ordinary steel is less reliable and grows weaker with time. 

In conclusion, galvanized steel is recommended, and if it must be welded, it should be done by a professional welder.

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