Notice before 1. construction

 

1.1 Personal Health and Safety Instructions

Most paints and thinners are harmful to human skin. Solvents in paints and thinners can seep into human skin and destroy fatty tissue. Can lead to chapped skin, allergies, eczema or skin infections.

1, should not wear chemical fiber texture clothing construction paint. When the paint used is solvent, it is recommend to use pure cotton overalls and solvent-resistant rubber apron protection.

2. It is recommended to wear comfortable and anti-static work boots. At the same time, work boots with steel vamp are beneficial to protect toes.

3. When handling and constructing paint, it is recommended to use PVC or nitrite rubber gloves to protect hands. Please do not use solvents to wash sticky paint on the skin, you should use a special skin cleaner.

4. Keep the construction environment safe and wear safety helmet and safety rope.

Most of the paint construction, surface treatment and drying process need to use respirators. Pay attention to the selection of appropriate types of filters for organic volatile substances.

6, should pay attention to the comprehensive protection of the eyes. Goggles with front and side shields may be used.

7. Keep the construction area clean and tidy, especially keep the passage and emergency exit unblocked.

8, do not drink construction.

9, the use of paint and near the paint construction placement area, please do not smoke and use any devices that will produce open flames.

 

Quick Guide to 1.2 Safety and Health Operations

 

Type of protective equipment	Recommended conditions of use
Protective clothing and anti-static boots	Mixing, handling and use of any paint product
Respirator	When the air contains volatile organic components and the ventilation conditions are poor, the respirator can be used to filter dust and organic volatile components.
Respiratory mask (oxygen supply)	Usually in paint spraying, or in small spaces with insufficient oxygen supply, and (or) when the air contains volatile organic components.
Gloves	When handling any paint product, especially if the paint is corrosive, toxic, allergenic or irritating, check the product's warning label
Goggles	When handling or using corrosive, irritating or allergenic paint products or when using thinners
Safety helmet	When there is a risk of falling objects, safety helmets must be worn in some designated areas.

 

Notes for 2. construction process

 

1.1 surface treatment

Manual or mechanical derusting on the surface. Shot blasting can be used for derusting in good conditions to remove the floating rust, welding slag, dirt and dust on the surface.

 

1.2 paint spraying

1. General coating

The quality of surface treatment must be strictly inspected, and no coating is allowed if it does not meet the requirements specified in the standard. For material painting work carried out in the open air, do not paint work in adverse weather conditions, such as high humidity and windy weather. Unless appropriate measures are taken to overcome these difficulties. During surface treatment and painting, the temperature of the surface to be treated shall be at least 3°C above the dew point of the surrounding air. When painting, the temperature of the surface to be treated should not be lower than 7°C and not higher than 38°C.

Open-air painting shall not be carried out in hot sun, rain, snow and fog; paint shall be painted when the paint on the metal surface condenses due to changes in metal temperature and ambient temperature.

In general, the coating should be carried out at a relative humidity of less than 85%. All surfaces shall be completely dry before and during painting and within 24 hours after painting.

(2) Cleaning of the air

Coating and film drying process to keep the surrounding air clean, not in a dusty environment coating.

3. Blending of paint

The blending of paint shall be carried out in strict accordance with the product instructions of the paint manufacturer. Before the paint is used, the paint must be mixed and fully mixed according to the regulations.

4. Brushing method

High pressure airless spraying method can be used for construction, and brush coating or compressed air spraying method can also be used.

Brushing: When brushing, make the paint brush dipped with an appropriate amount of paint, distribute it within a considerable range of the coated surface, first expand horizontally, and then straighten out longitudinally to make the paint evenly distributed. It can also be expanded vertically first, then straightened out horizontally, step by step, and do not omit.

Compressed air spraying: compressed air spraying is to use compressed air to attract (or press) the paint from the pot-shaped container to the spray gun. Under 0.2 ~ 0.5Mpa, the paint is mixed with air at the spray site and atomized, and sprayed on the surface to be coated. Uniform distribution of coating. Coatings used for compressed air spraying are thinner than brush and roller coatings, so some thinner needs to be added to general coatings.

High-pressure airless spraying: high-pressure airless spraying usually uses compressed air to drive a high-pressure pump to inhale and pressurize the paint to 10 ~ 25Mpa, pass through a high-pressure hose and spray gun, and finally spray it out through a nozzle with an olive-shaped hole. When the coating leaves the nozzle, it is atomized into very fine particles and sprayed onto the coated surface to form a uniform coating film.

Other requirements: in order to ensure the thickness of the paint film at the weld, edge, corner and other parts, a paint brush shall be used for pre-coating before large-area airless spraying.

5. Paint repair

Coating damaged during transportation or construction, bolt heads and nuts installed on site, and welding surfaces must be repainted. Before repair, oil stains on the surface must be cleaned with solvent and clean with water. After the specified surface treatment is completed, repair work shall be carried out and one primer and one intermediate paint shall be applied. The requirements for repainting are the same as before.

All primers, intermediate coats and topcoats shall be provided by the same paint factory, and the matching between these paint properties shall be guaranteed. The unpainted steel surface in the factory shall be painted with anti-corrosion materials approved by the Buyer for temporary surface protection.

 

1.3 paint film inspection

1. Appearance inspection of paint film

Check the surface condition of the paint film with naked eyes. The paint film shall be free of pinholes, bubbles, cracks, peeling, sagging, missing coating and other defects.

2. Film thickness inspection

Construction should be carried out according to the amount of coating, and often use the film thickness gauge to determine the dry film thickness (DFT), each coating should be measured the thickness of the film, after the coating is completed to determine the total thickness of the film.

For edges, corners, welds, cuts and other parts, one coat should be applied before spraying, and then a large area of coating should be applied to ensure the film thickness of the protruding parts.

3. Measurement of film thickness

For each coat of paint, the film thickness shall be measured once, and the total thickness shall be measured before leaving the factory. Final film thickness measurement after on-site touch-up and finish coating. The measurement can only be carried out after the paint film has completely dried.

4. Judgment criteria

If 5 or more defects are found on an area of 10 m2, the Buyer may consider the entire area to be defective in paint. The film thickness of 90% of the measured points must reach the specified standard value. If the number of points does not reach the specified standard value, the film thickness shall not be less than 90% of the specified standard value, otherwise, paint shall be applied again.

5. Film adhesion inspection

The inspection of paint film adhesion shall be conducted according to Grade 0-1 standard.