Coating construction technology of steel structure
In the normal use of steel structure, an important step to be carried out is the coating construction of products. The specific coating process steps, let's take a look together, which is helpful for everyone's use and production.
In order to prevent mispainting, the parts that are forbidden to be painted according to design requirements or steel structure construction process must be covered before painting. For example, the joint surface of foundation bolt, base plate and high-strength bolt shall be close to or embedded with concrete. The paint shall be fully shaken before opening the barrel. After opening the barrel, there should be no phenomenon of crust, caking, gel and so on. The sediment should be stirred up and the paint skin should be removed.
In the process of coating construction, the viscosity, consistency and thinness of the paint shall be controlled, and the paint shall be fully stirred during cashing to make the color and viscosity of the paint uniform. Special diluent must be used for viscosity adjustment, and test must be conducted if substitution is needed.
Environmental requirements of coating process: the environmental temperature shall be in accordance with the requirements of the product specification of the coating. When there is no requirement in the product specification, the environmental temperature shall be between 5-38 ℃, and the relative humidity shall not be greater than 85%; there shall be no condensation, moisture, etc. on the surface of steel structure components during coating; it shall be protected from rain within 4 hours after coating.
After the installation of steel structure, the second coating of anti-corrosion coating shall be carried out. Before coating, the surface of steel members shall be cleaned by means of abrasive cloth, electric wire brush, air compressor and other tools, then the damaged part and uncoated part of the coating shall be repainted, and finally the secondary coating construction shall be carried out according to the design requirements.
After the completion of coating, self inspection and professional inspection shall be conducted and recorded. When the coating has defects, analyze and determine the causes of the defects, and repair them in time. The repair method and requirements are the same as those of the formal coating. After the component is coated, it shall be temporarily enclosed and isolated to prevent the coating from being trampled and damaged; it shall not contact with acid liquid to prevent the coating from being bitten; when it is necessary to transport, it shall be prevented from bumping and dragging to damage the coating.
During the transportation, storage and installation of steel structure, the damaged coating shall be repainted. Generally, only one coat of primer will be applied after the factory is finished, and other primers, intermediate paint and finishing paint will be applied before hoisting at the installation site, and the last coat of finishing paint will be applied after the installation is completed; there are also cases where the primer and intermediate paint will be applied in the production unit after negotiation between the installation and the production unit, but the last coat of finishing paint will still be completed by the installation unit. In either way, the coating on the damaged part and the installation connection part shall be repainted. The number and requirements of touch up coating shall be the same as the original coating.