Marine spraying solutions

1. Technical requirements for ship painting

The main component of anti-rust paint is anti-rust pigment box film forming substance, is a kind of coating to protect metal surface from air, water, etc., or electrochemical corrosion. Antirust paint is divided into physical and chemical antirust paint two categories. Physical pigments and paints form film to prevent the invasion of corrosive substances, such as iron red, graphite anticorrosive paint, etc. Chemical by the chemical rust inhibition of rust pigments to prevent rust, such as red lead, zinc yellow anticorrosive paint. Usually used in various Bridges, ships, household pipes and other metal rust prevention.

2. Construction standards for ship paint

Ship spraying is generally used by high-pressure airless spraying, this high-tech paint construction method refers to the use of high pressure spray paint, paint at the nozzle outlet is forced to atomize, spray to the surface of the coating to form a paint film. Compared with spraying method, the use of airless spraying paint less flying, high efficiency and can be coated with thicker film, so it is especially suitable for large area construction application. But attention should be paid to fire prevention when using airless spraying. Therefore, pneumatic high-pressure airless spray machine has become the first choice for Marine spraying. At present, almost all shipyards use this machine when painting large areas.


3. Recommended spraying machine suitable for Marine spraying

HVBAN introduced the HB310/HB330/HB370 pneumatic spray machine series. Built around mobility and high performance, this cost-effective line of pneumatic spraying machines is the perfect complement to every Marine spraying team.
These proven and durable sprayers are ideal for high volume and high pressure waterproof, fire resistant and protective paint applications, offering great convenience and value to every contractor.

4. Ship paint construction technology

The ship is to be painted with several layers of anti-rust paint, primer, top paint and clear water paint. Ship paint suppliers usually send personnel to provide technical guidance at the construction site, and the requirements for paint are different in different environments and different humidity.

5. Specifications for ship painting

Ship paint is a kind of paint that can be applied to the surface of a ship. The main purpose of ship paint is to prolong the service life of the ship and meet the various needs of the ship. Ship paint includes ship bottom antifouling paint, drinking water tank paint, dry cargo tank paint and other paints. Next we will understand the characteristics of Marine paint and coating process.

6.1 Characteristics of ship paint

The size of the ship determines that the ship paint must be able to dry at room temperature. Paint that needs to be heated and dried is not suitable for Marine paint. The construction area of Marine paint is large, so the paint should be suitable for high-pressure airless spraying operation. Construction in some areas of the ship is difficult, so it is hoped that a painting can reach a higher film thickness, so thick film paint is often needed. The underwater parts of the ship often need cathodic protection, so the paint used for the underwater parts of the hull needs to have good potential resistance and alkaline resistance. The oil – based or oil – modified paint is easy to saponification and is not suitable for the manufacture of paint below the waterline. Ships from the point of view of fire safety, the engine room interior, superstructure interior paint is not easy to burn, and once burning will not release excessive smoke. Therefore, nitro paint and chlorinated rubber paint are not suitable for ship cabin decoration paint.

6.2 Requirements for ship paint coating process

1. Hull outer panel, deck panel, bulkhead panel, bulwboard, superstructure outer panel, inner floor and composite profiles and other internal panels, before unloading using shot blasting treatment, to meet the Swedish rust removal standard Sa2.5, and immediately sprayed with zinc rich workshop primer.
2. The internal hull profiles are sandblasted to meet the Swedish rust removal standard Sa2.5, and immediately sprayed with zinc-rich workshop primer.
3. After surface treatment, the workshop primer should be sprayed as soon as possible, and it is not allowed to be painted after returning rust on the steel surface.
Secondary treatment (hull surface treatment with primer or other coatings referred to as secondary treatment) its grade standards shall conform to the national and local standards.

6.3 Selection of ship paint

1. The selected paint must meet the specified technical conditions, unqualified paint is not allowed to be used for construction.
2. Before opening the can, we should first check whether the paint variety, brand, color and storage period are consistent with the requirements of use, and whether the diluent is compatible. Once the can is opened, it should be used immediately.
3. Paint should be fully mixed after opening the can, epoxy paint to add curing agent, thoroughly stir, pay attention to the mixing time, before construction. 4. During construction, if the paint needs to be diluted, appropriate diluent should be added according to the instructions of the paint manufacturer, and the amount of addition generally does not exceed 5% of the amount of paint.

6.4 Requirements for painting environment

1.Outdoor painting operation shall not be carried out in rainy, snowy, heavy fog and humid climate conditions.
2. Do not paint on wet surface.
3. Humidity above 85%, outdoor temperature above 30℃, below -5℃; The surface temperature of the steel plate is 3℃ below the dew point, and the painting operation cannot be carried out.
4. Do not work in dusty or polluted environment.

6.5 Process requirements for coating construction

1. The construction method of hull painting shall be carried out according to the following requirements:
a. The outer plate of the hull, the deck, the outer plate of the deck, the inside and outside of the bulwarks, and the parts above the flower plate of the rudder OARS in the engine room shall be sprayed.
b. Pre-paint manual welds, fillet welds, back of profiles and free edges before painting. c. Brush and roll coating shall be applied to other parts.
2. Construction shall be carried out in strict accordance with the List of paint grade, coating number and dry film Thickness of each part of the hull.
3. Paint must be cleaned in accordance with the requirements of the coating surface, inspected by specialized personnel and approved by the shipowner’s representative.
4. The type of paint tool should be suitable for the selected paint. When using other kinds of paint, the whole set of tools should be thoroughly cleaned.
5. When painting the last paint, the previous surface should be kept clean and dry, and the drying time is usually no less than the minimum coating interval time stipulated by the manufacturer.
6. In order to reduce the workload of secondary surface cleaning, where the weld, cutting, free side (free side requires chamfering) and fire burning parts (not including watertight test weld), should be immediately cleaned up after welding and cutting processing, with the corresponding workshop primer paint.

Post time: Mar-24-2023