Zinc Coating - The Complete Guide

Read this article so you gain knowledge on how zinc coating will keep metal products safe against rust.


What is Zinc Coating

Zinc coating has several qualities that can protect metals against corrosion. Among the other kinds of coating on metal, zinc coating is one of the best options. To gain further knowledge about zinc coating, its uses, benefits, and its capacity, take the time to read this guide.

What is Zinc Coating?

Zinc coating is the procedure of coating metals with a layer of zinc. This is an effective procedure for protecting the substrate from corrosion effects and other outdoor environmental elements.

The zinc coating is also referred to as zinc plating. It blocks corrosions to the metal by creating a physical obstruction. As a result, zinc-coated metals will remain rust-free for a long time.

what is zinc coating
How Long Zinc Coated Metals Stays Rust-Free

How Long Zinc Coated Metals Stays Rust-Free?

When applied, the zinc coating can protect metals from damaging rusts. It will also help the zinc-coated metals remain in good condition for 30 to 40 years. Aside from being rust-resistant, the coating also provides impact strength, better stability, and dimensional solidity to metals.

Its rust and corrosion resistance will be based mainly on the thickness and the coating type. This means the thicker the zinc coating on metals the longer it remains rust-free.

Benefits of Zinc Coating

Zinc coating, when layered on metal, gives special properties incomparable to other kinds of coating. The unique properties include:

  • Durability – Zinc coating provides durability to metal substrates.
  • Rust-free – Prevents moisture on the substrate.
  • Easy formability – It allows the formability of the substrate.
  • Light in weight – The coating does not add weight to the metal.
  • Affordable – It is lower cost than others but high quality.
  • Environmentally friendly and recyclable coating.
Benefits of Zinc Coating
Drying & Cleaning Process

Drying & Cleaning Process

Discoloration can be prevented when the zinc coating on metal is properly dried and polished. Here are the step-by-step procedures to avoid discoloration on metals.

  • Avoid using water when cleaning. Rather, wipe and rinse first the zinc coating using isopropyl alcohol.
  • After the coating is applied to metal and after cleaning using isopropyl alcohol, dry it with clean compressed air.
  • Finally, give the coated metal with a concise polish using a dried cloth.

Types of Metal You Can Zinc Coat

The zinc coating can be coated on different metal types. But the most common metal is steel or iron surfaces. You can coat different iron and steel components such as bolts, washers, nuts, and many more automotive components.

Metals layered with zinc coating provide several qualities. For example, it is a perfect, well-appropriate corrosion defensive coating for iron/steel parts. Its corrosion-free properties make it ideal for environments prone to damaging corrosions. This gives total protection to metals.

Types of Metal You Can Zinc Coat
thickness of zinc coating

Thickness of Zinc Coating

The thickness of the zinc coating will not affect the original weight of the metal. Its thickness is very thin –with a max thickness of 25 µm. Even though the coating is thin, it doesn’t compromise its quality and maximum protection.

However, it is easy to check the thickness of the zinc coating by yourself. You need to measure the two measurements – one without coating and another side with coating established. The height difference will be considered in its coating thickness.

Some Sectors that Uses Zinc Coated Products

Some Sectors that Uses Zinc Coated Products
Some Sectors that Uses Zinc Coated Products

Many business sectors gained a lot from zinc-coated products because of their durability and corrosion resistance. Known business sectors include:

Automotive Business. Many business owners prefer zinc-coated auto parts more than other coated parts. This is because they are the most economical coating method to secure automotive parts. Included automotive zinc-coated parts are brake pipes, brake calibrators, power steering systems, and many others.

Household Items. Businesses that focus on manufacturing household items choose to coat household items and appliances with zinc coating. The zinc coating adds extreme corrosion resistance, excellent quality, and durability to metals used in the household industry.

Construction Industry. Zinc-coated construction components add extreme durability and strength to buildings. Examples of zinc-coated construction parts are walls, stairs, roofs, columns, beams, and much more.

Hardware. In the hardware industry, zinc-coated products include bolts, nuts, screws, fasteners, coat nails, and more. This coating prevents the raw component from rusting quickly.

Plumbing Industry. Zinc coating is widely used in the manufacturing of plumbing components. The coating helps the piping protect against corrosion and possible leaking. This also preserves the pipe’s life – remaining quality up to 70 years of continuous use.

Why Zinc Coated Metals Corrode Over Time
Why Zinc Coated Metals Corrode Over Time?

Here are the chances why zinc-coated metals corrode over the years of use.

  • When exposed to the drenched or soggy environment
  •  More than 60% of the corresponding humidity
  • When cleaned or polished with sodium chloride from air/water.
  • The rising temperature when integrated with corroding factors such as industrial contamination and moisture.
  • When used in contact with sulfur acids. This acid is generated by hydrogen sulfide or sulfur dioxide contamination.
  • When exposed to caustic sodas.
  • When used in cement and plasterworks that carry sulfates & chlorides.
  • Soaked in acidic rainwater. It often affects zinc-coated roofs.
  • Vulnerable to acidic drinks and foods.
Anti-Corrosion Properties of Zinc Coating
Anti-Corrosion Properties of Zinc Coating

Climatic Corrosions. Zinc-coated metals have outstanding resistance to different climatic conditions. No matter whether these metals are exposed to urban areas, industrial, marine, or rural.

Water/Moisten Corrosions. The zinc coatings supply excellent protection for steel and iron in moistened and wet areas. It has the ability to resist damaging corrosion. This keeps the metals totally rust-free.

Ground Corrosions. No worries when your zinc-coated products are exposed to the ground. The zinc coating completely prevents the metal from corrosion.

Further Corrosion Substances. In many different applications of your zinc-coated metals, whether in cold or warm applications, rest assured the coating will give excellent protection. Zinc coating is the best option for metals requiring anti-corrosion properties.

Some Methods in Applying Zinc Coating on Metals

MetallisingThermal Spray Method
Metallising/Thermal Spray Method

The metalizing process is the procedure of spraying molten zinc onto manufactured metal products. This process utilizes powder-heated flame, plasma energy source, and arc spray. By zinc sprays, it can zinc coat up to 250 μm of various metals.

Electroplate Method
Electroplate Method

The electroplating method is an effective, flexible, and cost-effective method for layering protective zinc coatings to small metal parts. This is a broadly used method for fasteners, most especially those components with excellent threads.

Automatic Plating System
Automatic Plating System

The automatic plating system is electrolessly method of applying zinc coating on metals. It is a great option for malleable metals and is applied by a mechanical heat source. The coating thickness is frequently the same as the electroplated products.

Batch Hot Dip Galvanize Method
Batch Hot Dip Galvanize Method

The batch hot-dip galvanized method creates a uniform layering of zinc coating on different metals. It is applied spontaneously in any way and controlled by a professional operator. In this method, the molten zinc coats corners, secure edges, rivets, and seams of the metal. It will give thicker corners and thin edges to zinc-coated metals.

In-Line Galvanizing Method
In-Line Galvanizing Method

The in-line galvanizing method is effective in achieving smooth and uniform zinc coating on metals. This method is broadly utilized to enable precise control of coating ductility, thickness, and further quality properties. Appropriate for any metal components to fit various requirements.

zinc coat

Zinc Coating VS Galvanized: What Is the Difference?

Zinc plating and galvanizing are both used in the application method of zinc. But, what’s the difference? Zinc plating provides a typical thickness of 0.2 mils while the galvanizing offers a higher thickness – which is exactly 1.0 mm thick. Although the galvanizing adds weight to the substrate, they provide more than 5X the resistance.

All components to be galvanized are immersed in liquid, molten zinc. After that, this will guarantee the components are safe from rusting after many years even exposed outdoors. The galvanized zinc-coated product is guaranteed to have extreme protective properties.

However, zinc plating is widely used as surface treatment for commercial and industrial items. It is a popular coating for washers, automotive parts, nuts, bolts, washers, and more.

Zinc Coating Finishing Options

Zinc is a top coating that prevents corrosion of the steel component beneath it. This is by far the most cost-effective type of plating available.

The coating can be used to protect almost any sort of steel, particularly molds. It comes in a variety of finish colors and can be placed with or without dazzling accents. These are offered in green color, yellow, gold, blue, transparent, black, and more. Regardless of what color you choose, the coating acts as a protective barrier and could last for many years while remaining rust-free.

Color Finishing Characteristics

Yellow zinc is the most popular corrosion-resistant metal used in automotive components. However, the corrosion rate of black zinc is slightly lower than that of yellow zinc. The blue or clear zinc plating corrosion resistance is the lowest. Alkaline zinc coating gives products a brighter appearance while also keeping them from degradation.

Any Question About Zinc Coating?
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