What Is a Zinc Rich Primer?
A zinc rich primer is a primary rust-preventive paint that contains highly concentrated zinc powder. When applied to metal materials such as iron, the zinc powder contained in zinc rich primer corrodes before the iron base, thereby protecting the metal material inside.
In addition, painting with zinc rich primers forms a protective film, which makes the surface film more dense and prevents air and water from penetrating.
Applications of Zinc Rich Primers
Zinc rich primers are used on buildings, bridges, and steel structures to provide long-term protection against metal corrosion.
Since it contains a high concentration of zinc and is a type of corrosion inhibitor that is applied firmly, it adheres well and can be applied in places where hot-dip galvanizing with similar effects would be difficult to handle, such as seawater.
Examples include coating of ships, offshore structures, marine containers, and vehicles. Other applications include the repair of hot dip galvanized products.
Types of Zinc Rich Primers
There are two types of zinc rich primers: Type 1 inorganic zinc rich primers and Type 2 organic zinc rich primers.
Type 1 inorganic zinc rich primers are one-component, one-powder paints containing mainly alkyl silicates as the vehicle, and offer superior corrosion protection compared to Type 2 organic zinc rich paints. On the other hand, it has the disadvantage of requiring a high level of primer preparation and “mist coating,” in which a thinner-diluted, low-viscosity paint is applied over the topcoat.
Type 2 organic zinc rich primers are two-component, one-powder or two-component paints with epoxy resin as the main vehicle. Compared to inorganic zinc-rich paints, they are relatively easy to handle, with fewer restrictions on painting, etc., although their corrosion protection lasts shorter.