1. We have to consider whether the matching of the paint is correct, we know that most of the paint is organic colloidal material as the base material, we will paint each layer to form a film, there will inevitably be many tiny microporous, therefore, the corrosive medium will enter to erode the steel. Now we are in contact with the construction of coatings are not coated with a single layer but with multiple layers, the purpose of which is to reduce the microporosity to a low limit, the primer and top coat should be well adapted to each other. For example, perchloroethylene paint can be used with phosphate primer or iron-red alkyd primer, but not with oil-based primers. As perchloroethylene paint contains strong solvents, it will destroy the primer film.
2.Of course, the primer, intermediate paint and top coat of anti-corrosion paint must be used together. For components with general painting requirements, and when using hand and power tools to remove rust, two primers and two top coats can be used. For components with higher painting requirements and when using jet rust removal, it is appropriate to use two primers, 1-2 intermediate paints and two top coats, the total thickness of the dry paint film should not be less than 120μm, 150μm, 200μm, of course, for some parts that need to be aggravated anti-corrosion, the thickness of the coating can be increased appropriately, 20-60μm. for the thickness of the coating should be uniform, no pinholes, continuous and complete, it can achieve good anti-corrosion and anti-rust effect.
3.To consider the possibility of construction conditions, some suitable for spraying, some suitable, some dry film formation, etc.. In general, it is advisable to use dry, easy to spray cold-set paint.
4.To consider the use conditions of the structure and the consistency of the range of coatings selected, according to the situation of corrosive media, gas phase and liquid phase, hot and humid areas or dry areas and other conditions for selection, for there are acidic media, can be used acid resistance can be better phenolic resin paint, and relative to alkaline media, should be used better alkali-resistant epoxy resin paint.
