The construction process of offshore modified epoxy coating has the following special requirements due to the particularity of its application environment:
1. Substrate treatment
Before construction, surface treatment of the substrate is crucial. Since metal structures in the marine environment are easily corroded by seawater, salt spray, marine organisms, etc., the surface of the substrate must be thoroughly cleaned and rust-free. Usually, mechanical methods such as sandblasting or shot blasting are used to remove rust, scale, old coating, etc. on the surface of the substrate, so that the surface of the substrate reaches a certain degree of roughness to enhance the adhesion of the coating. For parts that are difficult to mechanically treat, manual polishing can be used, but it is necessary to ensure that the surface cleanliness meets the requirements. At the same time, the surface of the substrate needs to be degreased and desalted to prevent oil and salt from affecting the adhesion and performance of the coating.
2. Construction environment control
The offshore construction environment is complex and changeable, and the construction environment conditions need to be strictly controlled. First of all, it is necessary to choose a suitable construction time and avoid construction under severe weather conditions, such as strong winds, heavy rains, high humidity, etc. High humidity will affect the drying speed and performance of the coating, and may even cause bubbling and peeling of the coating. Secondly, the construction temperature also needs to be controlled within a certain range. Too low a temperature will slow down the curing speed of the coating and affect the construction progress; too high a temperature may cause the performance of the coating to deteriorate. In addition, attention should be paid to the ventilation of the construction site to ensure that the coating can be fully dried and cured during the construction process.
3. Coating mixing and stirring
Offshore modified epoxy coating is usually composed of a main agent and a curing agent, which need to be mixed in a certain proportion before construction. The accuracy of the mixing ratio directly affects the performance and curing effect of the coating. Therefore, during the mixing process, precise measuring tools must be used and the proportions must be strictly followed in accordance with the requirements of the instructions. The mixed coating needs to be fully stirred to ensure that the main agent and curing agent are evenly mixed to avoid local uncured or uneven performance. The stirring time and speed also need to be reasonably controlled according to the characteristics of the coating. Generally, mechanical stirring is used to ensure the stirring effect.
4. Selection of construction method
The construction methods of offshore modified epoxy coating mainly include spraying, brushing and rolling. Different construction methods are suitable for different parts and construction requirements. Spraying can obtain a uniform and smooth coating, but it requires professional equipment and technicians, and attention should be paid to the pressure and spray angle of the spray gun during offshore construction to ensure uniform coverage and thickness control of the coating. Brushing and rolling are suitable for construction of small areas or complex parts, but attention should be paid to the direction and strength of the brushing to avoid sagging, missing brushing, etc.
5. Quality inspection and maintenance
After the construction is completed, the coating needs to be inspected for quality. It mainly includes the inspection of the thickness, adhesion, hardness, appearance and other aspects of the coating. If quality problems are found, they should be repaired in time. During the use of the coating, regular maintenance and inspection are also required to promptly detect and deal with damage and aging problems of the coating to extend the service life of the coating and protect the safety of marine structures.