Analysis of Film Thickness of Common Anti-rust Paints

There are many types of epoxy anti-proof paint, and different rust-proof paints should be selected according to the use environment and degree of corrosion, and there are also different construction and various parameters. The film thickness of epoxy anti-proof paint varies with different levels of corrosion. Generally speaking, the more serious the corrosion, the thicker the corresponding film thickness. However, thicker is not always better. There is a specific film thickness standard. Today, let's take a look at how many times general epoxy anti-proof paint needs to be applied and what is the common film thickness.

In actual construction, common epoxy anti-proof paints include alkyd acid, epoxy, acrylic paint, etc., most of which are used in general atmospheric environments with corrosion, while underwater environments can use chlorinated rubber paint, etc.

Iron red alkyd acid rust-proof paint is common and belongs to alkyd acid paint. Its anti-corrosion performance is average and it is mainly used in places with low corrosion requirements such as scaffolding, iron railings, and small parts. Iron red rust-proof paint can be applied without intermediate and topcoats. It is generally recommended to apply two coats, with a wet film thickness of 100μm and a dry film thickness of 60μm.

Red dan rust-proof primer is a modified alkyd acid resin paint. It is cheap and has good performance, but it is easy to precipitate and inconvenient to apply. Moreover, red dan has a strong odor. It is generally used outdoors and has similar usage scenarios as iron red rust-proof paint. It belongs to lightly anticorrosive paint and is now rarely used. It is recommended to apply two coats, but one coat is also acceptable. The wet film thickness is 100μm and the dry film thickness is 60μm.

In epoxy paints, the relatively common ones are epoxy zinc-rich primer and epoxy cloud iron intermediate paint, which are usually used together and are mostly used in occasions with high corrosion resistance requirements. They are often used in various steel structures, storage tanks, bridges, etc. Epoxy zinc-rich primer is generally applied with 1-2 coats, with a wet film thickness of 120μm per coat and a dry film thickness of 60μm. Epoxy cloud iron intermediate paint is usually applied with 2 coats, each with a wet film thickness of 120μm and a dry film thickness of 60μm. The specific number of coats should be determined based on the corrosion resistance requirements and corrosion level.

The topcoats commonly used are alkyd acid topcoat and acrylic paint. Acrylic topcoat has slightly better performance and longer service life than alkyd acid topcoat, but it is slightly more expensive. Alkyd acid enamel also has similar performance and price to acrylic topcoat. It is recommended to apply two coats of alkyd acid enamel, with a wet film thickness of 100μm per coat and a dry film thickness of 50μm. Acrylic topcoat is also recommended with two coats, with a wet film thickness of 80μm per coat and a dry film thickness of 35μm.

What we have discussed here are common paints used in ordinary anti-corrosion projects, and do not include construction parameters for heavy anti-corrosion paints. Generally, one coat of primer is applied, and two coats of topcoat are applied. Whether to use intermediate coats depends on the specific requirements, but in ordinary anti-corrosion projects, many do not use intermediate coats.