1. Adjust the coating to a suitable viscosity for spraying with clean water, and measure it with a Tu-4 viscometer. The appropriate viscosity is usually 20-30 seconds. If there is no viscosity meter available at the moment, visual inspection can be used: stir the paint evenly with a rod (iron rod or hammer) and lift it to a height of 20 centimeters to stop and investigate. If the paint liquid does not line continuously for a short period of time (a few seconds), it is too thick; If the line breaks immediately after leaving the upper edge of the bucket, it is too thin; When stopping at a height of 20 centimeters, the paint should form a straight line, and in an instant, it should break off and drip downwards. This viscosity is more suitable.
2. The optimal control of air pressure is 0.3-0.4 megapascals (3-4 kgf/cm2). Insufficient pressure can cause poor atomization of the paint, resulting in the formation of pitting on the surface; Excessive pressure can cause sagging and paint mist, which not only damages materials but also affects the health of operators.
3. The distance between the nozzle and the object surface is usually 300-400 millimeters. Too close is prone to flow and hang; The paint mist is uneven when it is too far away, and it is easy to present pockmarks. In addition, the paint mist is scattered along the way when the nozzle is far away from the object surface, causing damage. The detailed size of the interval should be adjusted appropriately according to the type, viscosity, and air pressure of the coating. The interval for slow drying paint spraying can be farther, while for fast drying paint spraying, the interval can be closer; When the viscosity is thick, it can be closer, and when the viscosity is thin, it can be farther away; When the air pressure is high, the interval can be farther, and when the pressure is low, it can be closer; The so-called 'closer and farther' refers to small-scale adjustments between 10mm and 50mm. If this scale is exceeded, it will be difficult to obtain the desired paint film.
4. The spray gun can move up, down, left, and right. It is best to operate uniformly at a speed of 10-12 meters per minute. The nozzle should be straight to the surface of the object for spraying, and diagonal spraying should be minimized as much as possible. When spraying on both ends of the surface, the trigger of the spray gun should be quickly released to reduce the paint mist. As the two ends of the surface usually need to withstand more than two sprays, it is the easiest place to form a sagging.
5. When spraying, the next layer should press down on 1/3 or 1/4 of the previous layer to avoid any missed spraying. When spraying fast drying paint, it is necessary to spray it in sequence at once. The spraying effect is not ideal.
6. When spraying in spacious outdoor areas, attention should be paid to the wind direction (not suitable for work in strong winds), and the operator should stand in the downwind direction to avoid paint mist being blown by the wind onto the already sprayed paint film, forming an ugly granular appearance.
7. The order of spraying is: difficult first, easy second, inside first, outside second. First high, then low, first small area, then large area. This will prevent the formation of spray paint mist from splashing onto the already sprayed paint film and damaging it.

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