What is Galvanizing?

Galvanization, or galvanizing, is the process of applying a protective layer of zinc to steel or iron to prevent rusting and corrosion. The most common method is hot-dip galvanizing, in which the base steel is coated by submerging it in a molten zinc bath.

Here at Baling Wire Direct, we use hot-dip galvanization on our galvanized wire products

The history of galvanization

The history of galvanization dates back over 300 years. Here are some key galvanization facts:

  • The history of galvanized steel can be traced back over 300 years when an alchemist dreamt of immersing clean iron into molten zinc, leading to the realization of this process in the 18th century.
  • The process is named after the Italian physician, physicist, biologist, and philosopher Luigi Galvani (1737–1798).
  • In 1824, the British chemist Sir Humphrey Davy discovered that when two different metals were submerged in water, the corrosion of one would protect the other metal from corrosion, leading to the industrial prominence of the galvanizing process.
  • The name "galvanizing" was first applied to the process invented by Stanislas Sorel, a French civil engineer, inventor, and chemist, in 1836.
  • By 1850, British steelmakers were using 10,000 tons of zinc annually to protect iron from rust, indicating the widespread adoption of galvanized steel for corrosion protection.
  • The term "galvanizing" has largely come to be associated with zinc coatings in modern usage.

The history of galvanization continues today as advancements in metallurgy continue to drive developments in the process.

Galvanized steel properties

The properties of hot-dip galvanized steel include:

  • Corrosion resistance. Galvanized steel resists corrosion up to 100 times better than uncoated steel, making it highly durable and long-lasting.
  • Surface appearance. All galvanized steel has a matte-gray appearance. The zinc coating applied by electro-galvanizing is smoother than galvanized steel made with hot-dip galvanization.
  • Formability. The zinc coating on galvanized steel is resistant to cracking and loss of adhesion, making it highly formable.
  • Durability. The galvanized coating is extremely durable and resistant to scratches from abrasion.
  • Recyclability. Galvanized steel is as recyclable as other types of steel, making it an environmentally friendly material.
  • Long life. Hot-dip galvanized steel has a long life, requiring less maintenance and offering a low long-term cost.
  • Versatility. It is applicable to a variety of projects and industries, including agriculture, solar, automotive, and construction, due to its strength, formability, and corrosion resistance.

Different types of galvanization

Metal can be galvanized through several different processes, including:

  • Hot-dip galvanizing. This involves immersing the base metal into a bath of molten zinc, providing a complete zinc coating. It is the most popular and trusted method of galvanization due to its thorough coverage and durability.
  • Electro galvanizing. This method does not use a molten zinc bath. Instead, it involves applying zinc in a thin coating to the base metal, typically through an electroplating process.
  • Galvannealing. A process that combines hot-dip galvanizing and the annealing process, resulting in a zinc-iron alloy product with a dull matte surface. It is conducive to welding and provides an excellent surface for paint adhesion.
  • Pre-galvanizing. Similar to hot-dip galvanizing, but performed at a steel mill, where the steel is coated with a layer of zinc before it is formed into the final product.

At Baling Wire Direct, we prefer the hot-dip galvanizing method. This method allows us to avoid the use of caustic solutions, protecting our workers and the environment.

Our hot-dip galvanizing process

Our hot-dip galvanization process involves the following steps:

  1. Surface preparation. First, the wire undergoes a cleaning process to eliminate any impurities from the exterior of the metal. This purification ensures the adhesion of the zinc coating.
  2. Pickling. We then submerge the wire in an acidic solution to strip off any remaining oxides and residue. This process primes the surface for galvanizing by generating a pristine foundation.
  3. Fluxing. We soak the wire in a flux solution (zinc ammonium chloride) that hinders oxidation and enables a uniform coating of zinc.
  4. Molten bath. We then plunge the wire into a bath of zinc heated to around 450°C (850°F).
  5. Alloy formation. While immersed in the pool of zinc, a strong bond occurs between the iron in the wire and the zinc, forming a sheet of distinct iron-zinc alloys.
  6. Extraction. We then gradually extract the wire from the zinc bath. We control the extraction pace to enable excess zinc to drain off and ensure an even coating on the final product.
  7. Quenching. We then quickly cool the coated wire in water or a cooling solution to solidify the protective zinc coating and complete the galvanizing process.

Our multifaceted technique generates galvanic protection that safeguards against the elements.

We sell galvanized bale ties and galvanized wire by the stem.

Class 3 galvanization

We offer two classes of galvanization. Class 3 galvanization offers significantly higher corrosion resistance than the standard Class 1 galvanization. Here are some of the differences between the two classes:

  • Class 1 galvanization. Our Class 1 galvanized metal wire offers a basic zinc coating that uses 0.28 ounces of zinc per square foot. Class 1 galvanized wire is more cost-effective, but will typically rust after anywhere from 2–11 years, depending on the environment. In coastal areas, Class 1 coating fails even sooner due to saltwater corrosion.

Class 3 galvanization. With 0.80 ounces of zinc per square foot, this premium galvanization is nearly 3 times thicker than Class 1. The robust coating offers a higher degree of protection, providing a lifespan of 13–30 years. While it involves a higher initial cost, Class 3 galvanization is the ideal choice for harsh environments.

Baling wire products we offer

Baling Wire Direct sells the following high-quality baling wire products.

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