The continuous contact with seawater of boats and resorts near the sea causes acid corrosion to occur faster, and structures rapidly degrade and fail. Using marine construction paint is a solution against strong corrosion of sea salt.
1. What is marine construction and its main features
Marine construction paint is a type of paint with very effective alkali resistance, used for coastal constructions, salinity, alum contamination, … Paint for marine construction has 2 main types:
Paint water-based waters:
Specialized paint for works in coastal areas, areas subject to salinity or the area affected by sea winds. Water-based marine paints are applied with an alkaline, salt-resistant primer, and covered with water-based porcelain enamel.
Born with 2 lines of paint, which are anti-rust paints for marine areas and paints for marine colors.
Oil-based marine paint is used for projects in direct contact with seawater such as ships, seagoing boats, drilling rigs, … and is also used as anti-corrosion paint for marine structures.
Primer with salt resistant primer.
The required standards of anti-wear paint for marine structures:
- Adhesion on steel is high.
- High resistance to corrosion.
- The durability of the coating system under the impact of extreme weather.
- Chloride ion to prevent the intrusion of chloride ions through the paint film and react with the building materials.
- High salt-blind strength with long protection time.
- Good moisture resistance.
2. General properties of marine building paint
Because of these outstanding points, epoxy / polyurea paint is still preferred for marine projects over alkyd. The characteristics of this paint line are:
- High adhesion, quick-drying paint: For anti-rust paint for marine projects, because the smoothness is not high, the drying time is very short. Oil-based paints will have a longer drying time. When dry, the paint film is hard and adhere to the construction surface.
- Weather fastness: Paint film for marine structures is very resistant to weather and acidity, often with very bright colors and very fast color. At the same time, the gloss also increases the life to avoid effects from the outside environment.
- Very good resistance to rust and abrasion: As a specialized paint for the sea, epoxy / polyurea oil based paint has outstanding salinity resistance, minimizing the impact of acids and sea salt on materials. construction of marine works.
3. Construction of paint works for marine areas
The way to apply oil-based or water-based paint is the same as for conventional constructions.
Step 1: Clean the construction surface
Clean the construction surface from stains, grease, rust, adhesion organisms, … to create good adhesion to the paint film.
Clean oil and grease stained with solvents such as gasoline, kerosene, … for small contaminated areas, for large contaminated areas, physical effects can be used to clean and disinfect with emulsion .
Use a steel brush, a grinding machine, … to treat small patches of rust on the surface, or old paint, … stains that cannot be handled by spraying.
Sandblasting is a popular cleaning method, blasting strength depends on the stains you want to remove, crushed slag, rust, foreign objects, …
Wet abrasion by spraying low pressure water then adding abrasives such as sand, … then spraying high pressure compressed air onto the surface. When completed, it will form a powder-like rust on the surface.
Using a heated oxygen-acetylene or oxygen-propane flame, leach off based on uneven expansion between metal and rust.
Use acid to soak steel and then wash it with water, you can remove grease, wax, … This method is only used in the factory.
Step 2: Construction conditions
- Synchronize paints with solvents and paint additives if any.
- Use paint suitable for the steel structure of the building.
- The weather is dry, the temperature and humidity are favorable, there is no strong wind, no humidity.
Step 3: Conduct construction
Constructed by rolling method
- The new high viscosity paint with a flat surface finish is suitable for this coating. The width of the roller is suitable for the steel area.
- Roller method is not used to roll wear-resistant primers.
- It is necessary to apply several coats for the coating to be uniform.
- The paint roller cannot be carried out in corners or bolted positions.
- This method is used to apply paint at corners, bolts, small angles that the paint roller or spray method cannot cover.
- Work on the building surface with pockmarked, concave, welds, corner or joint area of the joint boards.
- It is necessary to cover the surface with paint and then apply the next coat.
- It is a very popular method when constructing marine construction, mainly conventional spray with low air pressure, electrostatic spray, …
- It is necessary to select the appropriate viscosity paint, as well as adjust the spraying pressure, nozzle, distance and spray angle accordingly to have the paint film evenly.
- Proper shielding to avoid paint dust flying around during application.
- Spray vertical and horizontal paint lines perpendicular to each other to make the paint film flat and beautiful. Or you can spray along the lines of paint, this method helps to improve labor efficiency.
- Do not spray too thickly to prevent the paint film from drying unevenly on the outside and inside..
- Spray test first to adjust paint sprayer accordingly.
- Eliminate construction defects by paint sweeping method before spraying.
- The paint film is perfect for a project with standard thickness, adhesion and coverage.
4. Is seawater corrosion resistant paint expensive?
Paints for marine structures are usually packed the same, including 2.8 kg/bin, 3 kg/bin, and 16 kg/bin. Prices for marine buildings will therefore also vary with product weight and supplier.
Construction of marine paint is very important because of the very strong corrosive properties of sea salt. So is the price of seawater corrosion resistant paint expensive, which types of anti-wear paints are suitable for which steels, and for related information, contact NEWTEC on 0243552003 for a free consultation.