Water-based paint spraying skills of paint spray gun

There are many methods of water-based paint construction, such as rolling, spraying, brushing, etc. Among them, spraying is one of the most important methods of water-based paint construction. Coating the surface of objects by spraying method can obtain a thin and uniform coating film. For objects with different shapes, small holes, gaps, and unevenness, the spraying method can be used to obtain a uniformly distributed coating film. Also, spraying is faster and more effective than brushing for large areas to be painted.

Next, let me tell you about the skills of using a paint spray gun for water-based paint spraying:

1. Use clean water to adjust the paint to a suitable viscosity for spraying, and measure it with a viscometer. The appropriate viscosity is generally 20-30 seconds. If there is no viscometer for a while, the visual method can be used: stir the paint with a stick (iron or wooden stick) and lift it to a height of 20 cm to stop observation. It is too thick; if the line is broken as soon as it is separated from the upper edge of the barrel, it is too thin; when it stops at a height of 20 cm, the paint liquid is in a straight line, and the flow stops instantly and becomes dripping. This viscosity is more suitable.

2. The air pressure of the paint spray gun is best controlled at 0.3-0.4 MPa (3-4 kg force/square centimeter). If the pressure is too small, the atomization of the paint liquid will be poor, and the surface will form pitting; if the pressure is too large, it is easy to sag, and the paint mist is too large, which not only wastes materials but also affects the health of the operator.

3. The distance between the nozzle and the object surface is generally 300-400 mm. Too close is easy to sag; too far, the paint mist is uneven, and pitting is easy to appear, and the nozzle is far away from the object surface, and the paint mist scatters on the way, causing waste. The distance of spraying should be adjusted according to the type of paint, viscosity and air pressure. The spraying distance of slow-drying paint can be farther, and the spraying distance of quick-drying paint can be nearer; when the viscosity is thick, it can be nearer, and when the viscosity is thin, it can be farther; when the air pressure is high, the distance can be farther, and the pressure can be nearer when the pressure is small; A little farther refers to a small range of adjustment between 10mm and 50mm. If it exceeds this range, it is difficult to obtain an ideal paint film.

4. The water-based paint spray gun can be moved up and down, left and right, preferably at a speed of 10-12 m/min, and the nozzle should be sprayed straight on the surface of the object, and oblique spraying should be minimized. When spraying on both ends of the object surface, the hand that pulls the trigger of the spray gun should be loosened quickly to reduce the paint mist, because the two ends of the object surface often need to be sprayed more than twice, which is the most likely place to cause sagging.

5. When spraying, press the next one to 1/3 or 1/4 of the previous one, so that there will be no leakage. When the water-based paint spray gun is spraying the quick-drying paint, it needs to be sprayed in sequence at one time, and the effect of re-spraying is not ideal.