Let’s talk about surface treatment grades

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Surface treatment grade: As the saying goes, in anti-corrosion projects, to achieve qualified quality, 30% depends on the materials and 70% on the construction process. It illustrates the importance of construction within the entire project. During the construction process, the treatment of the base surface affects the overall quality of corrosion protection, which shows just how important this treatment is for a project. Regarding the technical requirements for any painting project, the surface cleanliness level of the steel surface prior to painting is related to many factors. Firstly, the operating environment of the coating is the most important factor and determines the surface preparation level. Coatings that are immersed in liquids for long periods, those exposed to corrosive chemicals or environments, and coatings in high-temperature conditions all belong to coatings that operate in harsh corrosive environments. Secondly, the type of coating to be considered is an important factor. Oil-based coatings and alkyd resin coatings can be used to clean steel surfaces that have not been thoroughly cleaned or that have been cleaned manually, and they are suitable for environments with moderate corrosion levels. Some epoxy coatings and rust-prone coatings can be used on steel structure surfaces that have been cleaned manually or with tools, and they can be employed for corrosion protection in corrosive atmospheres. Ethylene coatings and inorganic zinc-rich coatings have high requirements for surface treatment, demanding a level of Sa2.5 or higher. Economics is also a factor we take into account when determining the surface cleaning level. Generally speaking, the higher the cleanliness requirement, the higher the cleaning cost. For steel surface cleaning, achieving the most thorough cleaning level (Sa 3) requires a higher cost compared to the less thorough cleaning level (Sa 2). Surface cleaning of steel structural components used in harsh corrosive environments requires a very high standard, but in other situations, the cost-effectiveness of the coating’s service life is also an important factor in determining the level of cleaning required. Furthermore, the surface treatment grades and methods are also subject to relevant regulations or standards. If open-type shot blasting cleaning is subject to strict restrictions ； Furthermore, if the coating being removed contains lead or chromium, regulations related to waste disposal require that the area where the removal takes place be covered, and alternative surface treatment methods must be used. The surface treatment grade shall be determined by the engineer. The surface treatment work is carried out by the contracting company. Regardless of the technical requirements regarding the cleaning level, surface cleaning must be carried out thoroughly and completely as specified. If manual cleaning is required, then the entire surface must be cleaned manually. If it is required that the cleaning level reach the most thorough cleaning level, then the entire surface must meet the requirements specified for that most thorough cleaning level. Therefore, in our actual corrosion prevention design and construction management, it is necessary to analyze each situation on its own to ensure economic rationality.