As the demand for corrosion protection grows in the industrial and construction sectors, corrosion-resistant coatings play an important role as a key protective layer. These coatings extend the life of the structure by forming a protective layer to effectively isolate corrosive environments. There are various types of corrosion-resistant coatings, such as water glass cement, phenolic cement, furan cement, epoxy cement, etc. Different types of coatings have their own characteristics in terms of chemical composition, applicable temperature and application requirements, and can provide better protection against specific corrosive environments such as acids and alkalis.
Characteristics and construction points of various corrosion-resistant coatings
Water glass mastic
Water glass cement is formulated by water glass, curing agent and acid-resistant powder in proportion, and is suitable for acid-resistant environment. During construction, the curing agent and powder are mixed first, and then the water glass is added, and it is used up within 30 minutes. The curing environment should be kept above 15°C to ensure full hardening.
Phenolic cement
Phenolic cement is composed of phenolic resin and acid-resistant powder, which is suitable for highly corrosive environments. An epoxy primer is applied to the substrate prior to application to enhance adhesion. After preparation, it needs to be used up within 45 minutes, and the ambient temperature is controlled at 15~30°C to ensure the curing performance of the cement.
Furan cement
Furan cement is based on acid- and alkali-resistant furan resins and is suitable for high-acid-alkali corrosive environments. When formulating, the curing agent needs to be slowly added to the resin to prevent violent reactions. The curing period after construction is as long as 15~20 days, which needs to be carried out in a well-ventilated environment.
Epoxy cement
Epoxy cement has excellent adhesion and corrosion resistance, and has good stability to acid and alkali media, but the cost is high. Before construction, add diluents and plasticizers in order, and use them up within 30 minutes after preparation, and the curing temperature should not be lower than 15 °C.
Epoxy furan cement
This modified epoxy cement combines the advantages of epoxy and furan resins to improve acid and alkali resistance and service temperature. When the cement is prepared, it should be heated to 40 °C and stirred evenly. The curing time is long, and the ambient temperature should not be lower than 20°C after construction.
Epoxy coal tar cement
Water resistance and toughness are improved by adding coal tar. Coal tar is heated and dehydrated before being added to epoxy resin in proportion. The curing temperature of the coating should be kept above 20°C, and the curing period should be 15~20 days.
Unsaturated polyester cement
It has certain acid and alkali resistance, and is suitable for scenarios with high mechanical strength requirements. Initiators and accelerators need to be added step by step during the preparation process to avoid safety problems caused by too rapid thermal reaction. The ambient temperature of the construction should not be lower than 20°C.
Construction environment and precautions
The construction of corrosion-resistant coatings has strict requirements for temperature, humidity and other conditions. Most coatings need to be kept at 15~30 °C at the construction temperature, and the humidity should not exceed 80% to ensure the film-forming quality of the cement. The curing process should be strictly avoided from contact with water vapor and direct sunlight to prevent the coating from failing. At the same time, the construction site needs to maintain good ventilation and pay attention to fire prevention to ensure the safety of construction personnel.
summary
The choice of corrosion-resistant coating should be based on the specific corrosive environment and engineering requirements. Water glass cement, phenolic cement, furan cement, etc. can provide reliable anti-corrosion effect, while epoxy cement is widely used because of its high performance and wide applicability. Proper selection and correct application can significantly improve the corrosion resistance of the coating and ensure the long-term stability of the structure.
