At present, the most common anti-rust paints are epoxy and alkyd, and the service life is 1-2 years. If the adhesion of alkyd on the galvanized sheet and aluminum sheet is poor, it is generally required. The materials are steel and concrete, and the adhesion ability of these coated substrates epoxy antirust paint is better, and this super strong adhesion is innate. This article mainly popularizes the coating knowledge in this aspect.
The widely used anticorrosive and anticorrosive primer on steel equipment is an epoxy zinc-rich primer. The specific thickness of the coating is determined by the period of use of the anticorrosive coating, the surface treatment of the substrate, and corrosive factors. When directly coating the blasted steel structure and steel components, it is required to increase the roughness of the surface of the substrate by grinding, and the roughness conforms to the standard of 50 μm. When used as an anti-corrosive primer, the recommended dry film thickness of the manufacturer is 60μm. It is better to spray it once without air spray, while the brush is only used for small-area spraying. When air-spraying, it needs to be painted twice; When used as a shop primer, it generally provides 3-6 months of anti-rust function, and is usually used for temporary anti-corrosion coating of workpieces, but this does not affect the welding performance. For welding requirements, the dry film thickness is generally required to be 25μm. . According to actual engineering experience, long-term outdoor steel structure anti-corrosion and decoration engineering needs to increase the dry film thickness to 70-80μm.
Zinc-rich primer is a porous coating. When used in combination with intermediate paint, the coating interval is generally 16-24 hours. The coating process is: when applying the first pass, it needs to add about 50% thinner, fog. Spray it once and then spray it normally. It can effectively avoid the problems of various zinc-rich primer coating manufacturers such as foaming.