1. What is a heavy-duty anti-corrosion coating and what are its characteristics?
Heavy-duty anti-corrosion coating, also known as high-performance anti-corrosion coating, is characterized by the use of high-grade anti-corrosion coatings and zinc-rich primers, and the use of thick build varieties.
The reason why the coating is anti-corrosion is mainly to use the coating to isolate the influence of the corrosive medium in the environment on the metal. For this reason, the coating should have the following characteristics:
(1) The permeability to water, oxygen and corrosive media is extremely small;
(2) Strong adhesion with primer and durable;
(3) The paint formula is appropriate (including anti-rust pigments and necessary additives);
(4) coating thickness;
(5) Appropriate coating supporting system is available.
In the heavy anti-corrosion coating system, epoxy resin, vinyl resin, chlorinated rubber, polyurethane, acrylic resin, epoxy-tar pitch and other base materials are often used. Their respective characteristics are:
Epoxy resin: water resistance, chemical resistance and good adhesion;
Vinyl resin: low temperature drying, good water resistance, chemical resistance and weather resistance;
Chlorinated rubber: low temperature dry operation, low permeability to oxygen and water vapor, good weather resistance;
Polyurethane: low temperature dry operation, good water resistance, chemical resistance and weather resistance;
Acrylic resin: good weather resistance, light resistance and color retention;
Epoxy-tar pitch: Good water resistance.
In addition to general weather-resistant and chemical-resistant pigments, the pigments used should focus on choosing scaly pigments, such as aluminum powder, mica, iron oxide, etc.
2. How to use heavy-duty anti-corrosion coatings?
(1) Choose a primer made of anti-rust pigments (such as red lead, zinc chromate, silver chromate and zinc powder, etc.) that can passivate metal or have cathodic protection properties. At present, most of them use zinc-rich primers.
(2) Select an intermediate layer paint with strong adhesion, such as mica iron epoxy polyamide intermediate layer paint, acrylic polyurethane intermediate layer paint, etc. (Adhesion Tester can be used to measure adhesion)
(3) Use topcoats with good weather resistance and decorative properties, such as polyurethane and acrylic topcoats.
