The cost of hot-dip galvanizing is lower than the use of alternative coatings. Painting, too, is a very laborious process, compared to hot-dip galvanizing, which is highly mechanized, carefully controlled process. Since the zinc coating is formed by immersing steel into molten zinc, all parts of the surface become coated inside, outside, as well as awkward angles and narrow slits that would not be covered when applying the protective coating in any other way.
Galvanized coatings protect steel in three ways:
- The thickness of the coating decreases very slowly and gives a long-lasting and predictable life to the structure.
- If the surface is damaged to iron, then zinc and iron form a galvanic couple, in which iron is a less active metal, as a result of which zinc in the coating enters the corrosion reaction first, and the main iron remains practically “untouchable”.
- If the damaged area is large, zinc protection prevents lateral rust creepage, which can undermine a large area of coverage.
According to the American Galvanizer Association, hot-dip galvanizing provides protection against corrosion:
In the industrial environment: 65 years
In the tropical environment: 70 years
In the suburban environment: 85 years
In the country environment: 120 years.