Galvanized steel tubing is a great way to cut costs if you're currently working with stainless steel or painted metal tubes. There's a good reason galvanization is the most popular way to protect steel tubing.
What Is Galvanization?
Galvanization is a process used to make steel more durable and resistant to corrosion. The tube is given a generous coat of zinc, which protects the metal from scratching, other surface damage, and rust.
How Is It Done?
Usually, the tube is hot-dipped in melted zinc. This submersion process allows the zinc to bind tightly to the metal's surface. There are other galvanization methods, such as painting, spraying, sheet galvanizing, and electroplating, but none offer the complete coverage or durability of hot-dipping.
Pros:
Cost
Compared to other protective coatings and methods, galvanization is incredibly affordable. Labor-intensive coatings such as painting cost more to cover the salary of the painters; with hot-dipping and other machining methods, the client pays much less for the cost of factory operations. Similarly, compared to the cost of stainless steel, galvanized steel is quite cheap.
Further, galvanization lasts longer than other coatings, and requires less maintenance. Even tubes with small damaged areas will not need touch-ups, which saves in upkeep costs.
Coverage
Due to the complete submersion of the hot-dipping method, every inch of the metal will be protected. Even the most difficult corners and pockets will receive a generous protective layer.
Durability
Galvanized steel tubing can last more than 50 years in most conditions. The coating itself is bonded permanently to the metal, making transportation and installation stress-free for both the metal and its owner.
Due to a phenomenon called preferential corrosion, the zinc coating will rust and corrode before the steel, even if small areas of the zinc are damaged. This means the metal won't need touch-ups, unlike many organic coatings.
Environmentally Friendly
Galvanization is considered the most environmentally friendly protective coating. It produces only small amounts of waste and is recyclable without losing any beneficial properties of the metal.
Cons:
Not as Effective in Extreme Conditions
Although galvanized steel tubes have the potential to last more than 50 years without maintenance, that number gets cut in half in extreme conditions. In cases where the metal is exposed to the elements (salt water, rain, harsh weather) the zinc coating will corrode more quickly. Typically, even under stressful conditions, a galvanized steel component can last more than 25 years.
Physical Limitations
Some objects can't be hot-dipped due to their size. A tube that is too large or small will be difficult to get through the process.
Manufacturer Errors
If the manufacturer makes an error (such as cooling too quickly), the zinc layer will peel or chip off the tube.
Is It Right for You?
Despite the potential cons of galvanized steel, many industries benefit greatly from its low cost and long life. Even in the most extreme conditions, such as marine applications, galvanized tubing demonstrates high quality and durability.
If your project requires a cost-effective coated metal tube, galvanized steel is the most economical option.
