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What’s the difference between Cold Galvanizing and Hot Galvanizing?

Cold Galvanizing vs. Hot Galvanizing: Know the Difference Get a clear explanation of the key differences between cold galvanizing and hot galvanizing.

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Galvanizing is a method of creating a zinc coating on the surface of iron and steel products to protect the product from rusting under the impact of the environment and weather over time. So what is the difference between the two popular galvanizing methods today, hot-dip galvanizing and cold galvanizing? Join us for a detailed look at the information related to these two methods and compare cold galvanizing with hot-dip galvanizing.

The difference between Cold Galvanizing and Hot Galvanizing: definition, application, process

Humans are constantly looking for ways to improve the life of metal materials in corrosive environments. One of the most widely used techniques to protect metals (mainly steel) is galvanizing. Hot-dip galvanizing and cold galvanizing are the two most popular names on the market. To better understand the difference between the two methods when choosing, let’s explore the definition, application, and process in the content below.

1. About Cold Galvanizing method: definition, application, and process

Definition

Cold galvanizing is a more straightforward technique that involves painting zinc-rich paint on the material’s surface to protect it against corrosion and improve its appearance. Galvanized paint can be applied using a brush, roller, spray gun, or electroplated. Galvanized paint, unlike regular paints, has a bonding component that allows the zinc in the paint to bind with the metal mechanically. As a result, an adhesive coating with a high level of protection is created.Like hot-dip galvanizing, cold galvanizing also offers two types of protection: passive and cathodic protection. To get the most excellent paint look, make sure the surface is clean and dry and remove any dirt or rust stains.

Application

Cold galvanizing technology has high advantages because it can be used in many different plating fields. Currently, cold galvanizing technology is also an effective solution to replace hot galvanizing gradually. Accordingly, it is often applied to galvanize materials with complex, large, and fixed structures such as pipes, tanks, seaports, irrigation works, and bridges metal used for a long time, good corrosion resistance with time. Galvanizing paint is relatively simple to do, which is why it has become increasingly popular in plating in recent years.Cold Galvanizing thumbnail-vivablast

Process

Description of the cold galvanizing method: This plating technology applies a layer of liquid zinc to the metal surface. It is almost like you paint a layer of paint at an average temperature. Then, a stream of compressed air is blown into the liquid solution to form a beam of zinc particles that shoot onto the surface of the plated metal. When the air is done, the zinc coating solution and additives will stick very firmly to the metal surface, and after a few hours, they will harden and create a protective layer on the surface.Cold Galvanizing 1-vivablast

2. About Hot Galvanizing method: definition, application, and process

Definition

Galvanizing creates a protective layer on the metal surface from oxidation and wear, thereby helping the metal be more robust and have a longer service life. Of the three widely used galvanizing methods, hot-dip galvanizing, electrolytic galvanizing, and cold galvanizing, hot-dip galvanizing are the most common.To galvanize metal by the hot-dip method, we dip the metal to be galvanized into a bath of molten zinc at temperatures of around 840°F (449°C). This method causes the outer layer of the metal to be melted into an alloy with zinc. This helps to coat the zinc on the metal surface evenly and makes it difficult for the zinc layer to peel off, helping to protect the substrate surface effectively.

Application

The application areas of hot-dip galvanizing can be mentioned as chemical industry, pulp, paper, automobile manufacturing, telecommunications, lighting, and transportation…, but are not widely used in steel factories. Most of the industries that apply this method uses a large amount of iron and steel, but often rust due to oxidation under the influence of the environment. The hot-dip galvanizing technology has improved corrosion control and extended the life of items and works.

Process

The galvanizing reaction occurs when the temperature is between 454°C & 465°C. Completely immerse the surface-prepared and dried metal in the galvanized bath. The molten zinc will wet the metal surface, and a galvanizing reaction will occur, forming zinc alloy layers. When the temperature in the galvanizing bath reaches the melting point (standard temperature is 454°C), the galvanizing reaction is complete. Carry out slag scraping on the molten surface and combine with vibration to remove excess. Then dip the product into the chromate solution to create a protective layer for the surface.During the galvanizing process, care should be taken to completely immerse the metal in the tank for an even coating. In addition, depending on the desired thickness of the galvanized layer, it is necessary to align the corresponding dipping time. Avoid dipping for too long, causing the plating to be too thick, reducing adhesion and not aesthetically pleasing.

3. Comparing Cold Galvanizing and Hot Galvanizing? Basic Differences

After studying the details of cold galvanizing and hot dipping galvanizing, we can draw some comparisons as follows:Hot-dip galvanizing is a chemical treatment that involves electrochemical reactions. Meanwhile, cold plating is a simple physical method, just applying a layer of paint to the surface.Both methods work to protect the inner metal layer from corrosion and rust. However, the protection of hot-dip galvanizing will be much higher than that of cold galvanizing. Because the thickness of the hot-dip galvanizing layer is more increased, it covers the entire inside as well as the outside of the material.Although not as protective as hot-dip galvanizing, cold galvanizing has its unique benefits. This is a quick and effective method on hard-to-reach structures, fixed components. Hot dipping is also far more costly than cold plating and takes a huge number of people to complete.As can be seen, cold galvanizing and hot dipping galvanizing have different properties and benefits. The ultimate choice of galvanizing method is finding the right balance between cost and coating performance for a given application. Besides, the choice of service to perform the construction of the material protection system is critical in deciding the structure’s ultimate efficacy.Cold Galvanizing 2-vivablastVIVABLAST has advanced and effective metal protection products with a team of experienced technicians who will evaluate the structure to give you a comprehensive protection solution – safe and cost-effective.

About Us

Vivablast was founded in 1994, as a 100% foreign-owned company with an ambition to become the most preferred and trustful service provider for industrial assets protection in Southeast Asia.

Over the past two decades, Southeast Asia experienced rapid economic growth with significant investments in industrial facilities, equipment, and infrastructures of Oil and Gas, Renewable Energy, Marine, Power Generation & Manufacturing sectors.

Hence, Vivablast has succeeded as a reliable subcontractor for many International & Domestic companies by delivering our professional services to such prestigious companies as PIRIOU, JGCS, Technip, KNOC, Metacor, PTSC groups, Vietsovpetro, etc. with great passion.

Our innovative system of mobile blasting & painting workshops can be mobilized anywhere in Southeast Asia for all major projects and infrastructure sites, which has performed very well during Vietnam’s first refinery project – Dung Quat followed by Vung Ang 1.2 Power Plant project and the biggest Oil & Gas complex in Vietnam – Nghi Son Refinery.

In 2014, Vivablast landed in the soils of Thailand, Myanmar, and Malaysia to capture the growing demands of customers at any time and anywhere.

Over 28 years of steady deliberate growth, we feel confident and proud of our team and their capacities to play a vital role in the multi-disciplinary industrial services provider.

Why Choose Us?

Expertise of industrial assets preserving since 1994

FAQs

Vivablast is a company that offers surface preparation and industrial painting solutions for various industries such as oil and gas, marine, construction, and mining. Some of the solutions they offer include abrasive blasting, hydro blasting, tank cleaning, industrial coating, and passive fire protection.

Board of Management

Mr Jacques Vivarès – Chairman
Mr Boris Vivarès – Vivablast Group General Director – Commercial & Business Development
Mr Shanthamani Muthukumar – Vivablast Vietnam General Manager

Vivablast is a global provider of industrial asset protection solutions in Vietnam, Thailand, Myanmar, and surrounding countries. Vivablast is a 100% foreign-owned Company accredited ISO 9001:2015 & ISO 45001:2018 by Bureau Veritas with offices and setup over South-East Asia. Since 1994, we have been servicing industry leaders in major projects from construction phase to maintenance programs. Our vertical expertise includes all industry sectors, particularly: oil & gas, power & utilities, shipbuilding, mining and manufacturing. We design and deliver professional services to preserve our Clients’ assets sustainably, through efficient and reliable specialty services and integrated solutions.

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