In today's rapid development of the coatings industry, all brands of coatings want to dominate. However, among many coatings, water-based coatings are still popular. This is a new type of coating. It uses its own advantages to make many people in the industry accept it and use it widely. Although it is so, there are still many people do not have a correct understanding of water-based paint, so there will be some misunderstandings when using it. Below we will introduce you to the use of water-based paint.
1. Use clean water to adjust the coating to a suitable spray viscosity, measured with a Tu-4 viscometer. The appropriate viscosity is generally 20 to 30 seconds. If there is no viscometer for a while, the visual method can be used: stir the paint with a rod (iron rod or wooden rod) and then lift it to a height of 20 cm to stop and observe. If the paint liquid is continuously lined for a short time (a few seconds), then it is too thick; if the broken line is too thin from the top edge of the barrel, it is too thin; when the paint is stopped at a height of 20 cm, the paint liquid will be in a straight line, and the flow will immediately drop to drop. This viscosity is more suitable.
2. The air pressure is best controlled at 0.3-0.4 MPa (3-4 kgf / cm2). If the pressure is too low, the atomization of the paint will be poor, and pits will form on the surface; if the pressure is too large, it will sag and the paint mist will be too large, which will waste materials and affect the health of the operator.
3. The distance between the nozzle and the object surface is generally 300-400 mm. Too close and easy to sag; too far paint mist is uneven, pitting is easy to occur, and the nozzle paint is far away from the object surface and the paint mist is scattered on the way, causing waste. The specific size of the distance should be adjusted according to the type of paint, viscosity and air pressure. The spraying distance of slow-drying paint can be farther, the spraying of quick-drying paint can be closer; when the viscosity is thicker, the distance can be closer; when the viscosity is thinner, the distance can be farther; Closer and farther refers to the adjustment of a small range between 10 mm and 50 mm. If it exceeds this range, it is difficult to obtain an ideal paint film.
Operation Skills Of Water-Based Paint Spraying Construction
4. The spray gun can be moved left and right, up and down, and it is best to operate evenly at a speed of 10-12 m / min. The nozzle should be sprayed straight to the surface of the object to minimize diagonal spraying. When spraying to both ends of the object surface, the hand that pulls the trigger of the spray gun should be loosened quickly to reduce paint mist, because the two ends of the object surface often receive more than two sprays, which is the most likely place to cause sag.
5. When spraying, the next layer should be pressed against 1/3 or 1/4 of the previous one, so that there will be no spray leakage. When spraying quick-drying paint, it needs to be sprayed in sequence at a time. The spraying effect is not ideal.
6. When spraying in an outdoor open area, pay attention to the wind direction (not suitable for operation in high winds). The operator should stand in the downwind direction to prevent the paint mist from being blown by the wind on the sprayed paint film and causing an unsightly granular surface.
7. The order of spraying is: difficult first, then easy, first in and then out. First high and then low, first small area and then large area. In this way, the spray paint sprayed afterwards will not be splashed onto the sprayed paint film and damage the sprayed paint film.
Any object or thing is not perfect, and the water-based paint is the same. Although it has its own advantages, there are still many problems, but we can continue to improve through the above processes and technologies, and some problems can be well prevention.
