What is Galvanization and Why Is It Used in Industrial Settings?
- Less Maintenance: They are self-maintaining and thicker. The maintenance costs of these steel items are inevitably lower.
- Long Life: Steel items can last more than 50 years.
- Lower Costs: Lower initial costs compared to other commonly specified corrosion protection coatings for steel.
- Quick Application: It only takes a few minutes to apply a full protective coating.
- Environmentally Friendly: The maintenance-free coating’s longevity provides environmental and economic benefits. Zinc is a natural element so the zinc byproducts are not harmful.
When it comes to coating and protecting metal, galvanizing is the most popular method. Galvanization is accomplished by applying a protective coating of zinc on to steel or iron. The coating is primarily used to prevent rust and corrosion, giving the product a longer life and increasing safety. Metal items are often seen with a dark silver coating, which is the color caused by the coating process.
Corrosion and rust can result in large issues for safety equipment because of the potential weakening of the structure and the increase in health risks.
A metal is more susceptible to oxidizing and corroding without galvanization. Galvanizing can also protect metal through a process called “galvanic corrosion.” As NACE International explains, “Galvanic corrosion refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone.” (https://www.nace.org/Corrosion-Central/Corrosion-101/Galvanic-Corrosion/)
Rust and corrosion can both result in serious issues for safety equipment because of the potential weakening of the structure and the increased health risks. If a worker was walking on a crossover platform with rust forming at its base, there’s a greater chance that the platform may collapse. Additionally, from a health perspective, even the smallest amount of rust/corrosion could lead to an infection if a laceration occurs.
The most common way to galvanize is with hot-dip galvanizing, in which parts are submerged into a bath of molten zinc. The base metal is first thoroughly cleaned (mechanically or chemically) to ensure that the zinc will bond for a long time. After cleaning, the base metal will be fluxed to remove remaining oxides. It will then be dipped into the zinc.
Electrogalvanizing is another method, yet less common. Rather than a heated bath of zinc, this method uses an electrical current inside an electrolyte solution. This process transfers zinc ions onto the base metal electrically by reducing the positively charged zinc ions to zinc metal, which are then deposited onto the positively charged material. Uniform coating is a big advantage of this process. However, the coating tends to be thinner, which could result in lowered durability.
Other Popular Industrial Coating Methods
Aside from galvanizing, there are some other well-known methods for coating metal industrial use. These include powder coating, painting, and staining. Each method has its own benefits and drawbacks.
Like galvanizing, powder coating is one of the top methods for industrial metal components. Powder coating is the method in which a powdered substance is electrostatically charged, usually via a spray gun, and then applied to the base metal component. Powder coating provides a durable and tough finish that’s resilient and reduces the damage caused by severe weather, impact, and chemicals. It also has lower chances of chipping and scratching.
As you likely already know, painting and staining are done using a liquid. They are not as durable as powder coating or galvanizing. The benefits of painting or staining include the ability to get a clean finish that can come in many different colors. Chips, scratches and can happen over time, especially in harsher environments like ports or foundries. They tend to have a low threshold for heat. Saltwater and chemicals can also break the coating down and lead to discoloration.
If you have any questions, please contact us for more information on which coating process is the best for your application.