Sandblasting process; In order to prolong the life of the metal in areas where metal surfaces are concentrated, especially in industrial facilities, the relative humidity, rainfall and surface temperature of the air should be taken into consideration.
The inner and outer surfaces of tanks, metal materials are cleaned with pressurized fresh water. Based on the corrosive and rust ratio of the surface, it is classified according to the degree of cleanliness and the rate at which the surface is abraded. S.I.S 055900 Swedish standards in Turkey "Swedish Standards for Ground Vibrations and Airblast" is used. This standard is known to TS EN ISO 8504. SA 1, SA 2, SA 2,5 AND SA 3 grades are included in the standard.
RATING THE BLASTING
SA 1: It is an extremely superficial cleaning degree. extremely superficial cleaning on rusted surfaces.
Sa 2: It is a highly cleaned form of rust and unwanted formations on rusted surface. Steel itself, gray color can be selected. It is an unacceptable sandblasting degree in the market. Because it is too much for superficial cleaning, but also for an in-depth cleaning.
Sa 2.5: The most preferred sandblasting degree in the market is that the steel is free from any rust and unwanted formations. The distinctive gray color of the steel appeared.
Sa 3: It is the highest degree of cleaning that can be done in sandblasting process and it is not preferred in the market like Sa 2. Because the cost and implementation time is quite high. It also means the wear of the steel, even in microns. This is contrary to the purpose of protecting the top steel.
Surface cleaning according to SA standards;
The cleaning values according to ISO 8501-1 are as follows.
< %80 Slightly cleaned
%80 Well cleaned
Sa 2 1/2
%96 Very well cleaned
%99 Completely cleaned.
Sanding degree is decided according to the desired cleaning rate. Washed, sieved and dried sandblasting sand is used. Unless otherwise stated, the roughened surface profile is intended to provide a roughness of 40-70 microns. It is aimed to clean the surface at least SA 2 1/2 quality. According to the specification of the paint to be applied, the required time is expected and the surface is intended to be suitable for priming. In this process, unsuitable places are sandblasted again.
It is applied to the surface cleaned by sandblasting. The paint application is shaped according to the working environment and material structure of the surface. The appropriate paint and paint thickness must be selected to increase the use of the material.
The dyeing process can usually be classified in 3 main layers; application of primer paint, application of intermediate coat and application of topcoat.
After sandblasting in industrial facilities, the primer coat is applied first. Surface tolerant epoxy paint, phenolic epoxy paint polyamine or polyamide epoxy paint etc. paint applied samples.
Intermediate and topcoat polyamide or polyamide epoxy paint, acrylic polyurethane paint, phenolic epoxy paint etc. industrial paints are applied.
Paint thicknesses to be applied for each layer, such as 100 micron primer, 100 micron intermediate coat, 50 micron final coat application, should be determined by the paint inspector. The most important parameter here is the painting of tanks, pipes, equipment and so on. the general conditions of the facility where the business is located and the fluid passing through it.
The surface to be painted is insulated or non-insulated, it is open or closed to external environment, it is not exposed to direct sunlight, acid, water, salt and so on. The information on exposure to aggressive chemicals is very important parameters in determining the thickness and type of paint.
When selecting the paint, care must be taken to find the following information in the technical data sheets.
- Pigment system element type and% by weight
- % Of volume of solids of paint + hardener mixture
- Filling system types and% s by weight
- Brightness (as Gloss)
- Drying times, Touch dry, complete drying.
- The amount of crush
- Consumption Kg / m² (required paint quantity per m² for the specified dry film thicknesses)
- Component mixing ratio. In%
- Pot life (time of application of the mixture)
- specific weight
- Flash point (in ° C)
- Thinner; chemical composition and dye compatibility
- Ultraviolet resistance
- Storage life: warranty period (-5 ° C + 35 ° C)
- 220.127.116.11 and 15 days after the application of the hardening amounts of paints; (ASTM D 1474)
- Amount of zinc in epoxy primer paint: Dry film will be indicated as% weight.
- The warranty period and storage conditions given