What kind of coating is good for galvanized pipe painting? Introduction of surface treatment before painting

Generally speaking, the coating products around us are often painted on the wall, mainly used in the home improvement industry, which can have a beautiful effect. However, there is another kind of coating used in industrial production on the market. They are not used to change the color of the object itself, but to protect it from corrosion. The galvanized pipe paint introduced to you today is one of the representatives of the latter. As the name implies, galvanized pipe paint is a kind of special paint coated on the surface of zinc pipe, which is often treated by electroplating process. Interested friends can refer to the following to understand this.

1. What coating is good for the surface of galvanized pipe?

Requirements for painting galvanized steel: Galvanizing is an important means to prevent corrosion and rust of steel structures. Generally, the surface after hot dip galvanizing has certain antirust and anticorrosive properties, but the color is not optional, and the galvanized layer is easy to be damaged and prone to local rust. Therefore, for many users with anti-corrosion and decoration needs, painting on the surface of galvanized steel structure is still the main means. Why is the surface paint of galvanized steel easy to fall off? Many users often have the following problems when painting galvanized steel surface: the paint falls off in pieces. The adhesion of galvanized steel surface is worse than that of ordinary carbon steel. Alkyd paint, nitrocellulose paint and even some epoxy paint with strong adhesion will have insufficient adhesion and fall off when painting.

Especially in the application of alkyd coatings, the saponification reaction between acid and zinc not only causes the loss of zinc layer, but also causes the waste and rework of coatings. There are mainly the following kinds of coatings on the surface of galvanized steel structure: epoxy zinc yellow primer, which is mainly used in fields with high decoration requirements, high weather resistance and high anti-corrosion requirements. Anti-rust primer for galvanized steel structure needs corresponding topcoat. Zinc epoxy yellow primer+acrylic polyurethane topcoat/fluorocarbon topcoat, etc. Epoxy ester zinc yellow primer, mainly used in some areas with low anti-corrosion requirements but certain requirements for surface decoration. The matching scheme is: epoxy ester zinc yellow primer+epoxy ester topcoat, epoxy ester zinc yellow primer+alkyd enamel phosphating primer. This paint can be used as the surface treatment primer of galvanized steel structure, that is, by brushing this paint, the surface suitable for brushing most paints, such as alkyd paint and epoxy paint, can be brushed on the surface coated with phosphating primer.

Second, the galvanized steel structure surface treatment before painting

1, the most basic oil and dust removal, to ensure that the surface is dry and clean. The surface to be sprayed can be wiped with the corresponding solvent.

2, conditional, can use phosphating treatment, sandblasting treatment, etc. The above are the main varieties of antirust primers for galvanized steel structures. The antirust paint for galvanized steel plate can be used as paint for galvanized surfaces such as galvanized pipes, galvanized plates and galvanized angle steels. All of the above three are primers, and epoxy ester and epoxy yellow zinc are used as antirust paints, and all of them need topcoats to meet the expected painting requirements.

The galvanized pipe paint we gave you as an example above is a special paint product. Different from other coatings, it exists not for aesthetic decoration, but for anti-corrosion protection. Therefore, it is often used in electric power and electrician industry. Coating a layer of paint on the surface of zinc pipe can play the role of anti-corrosion and post-protection of galvanized pipe, because long-term use will cause loss and safety problems. However, the construction technology of galvanized pipe in the early stage of painting is also very important.