Super practical seven water-based fireproof coating spraying construction operation skills

The spray method is Water-based fire retardant coating is one of the most important methods in the construction. The surface of the object is painted by spraying to obtain a thin and uniform coating film. For different geometric shapes, there are small holes. , gaps, unevenness, the paint can be evenly distributed; for spraying large surfaces, this method is faster and more effective than painting. However, some operating skills must be mastered for construction by spraying:

First, use a clean Water-based fire retardant coating should be adjusted to a suitable viscosity for spraying, and measured with a Tu-4 viscometer. The suitable viscosity is generally 20 seconds to 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 up to a height of 20 cm to stop observation. It is too thick; it is too thin if the line breaks as soon as it leaves the upper edge of the barrel. When staying at a height of 20 cm, the paint liquid will be in a straight line, and the flow will be cut off instantly and will become dripping down. This viscosity is more suitable.

Second, the air pressure is best controlled at 0.3~0.4MPa (3~4kgf/cm2). 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.

Third, the distance between the nozzle and the object surface is generally 300mm~400mm. When it is too close, the paint film is easy to sag; if it is too far, the paint mist is uneven, and pitting is easy to appear, and the nozzle is far away from the surface of the object, and the paint mist scatters on the way, causing waste. The specific size of the distance should be appropriately 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 fast-drying paint can be a little closer; when the viscosity is thick, it can be closer, 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 closer 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.

Fourth, the spray gun can move up and down, left and right, preferably at a speed of 10~12m/min. 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.

Fifth, when spraying, the next layer should press 1/3 or 1/4 of the previous one, so as not to Leakage will occur. When spraying quick-drying paint, it needs to be sprayed in sequence at one time, and the effect of re-spraying is usually not ideal.

Sixth, when spraying in an open space outdoors, pay attention to the wind direction (do not work in strong winds), and the operator should stand Downwind to prevent unsightly grainy surfaces from wind blowing paint mist onto the already sprayed paint film.

Seventh, the order of spraying is: first difficult and then easy, first inside and outside. High places first, then low places, first small area and then large area, so that the paint mist sprayed after spraying will not splash on the sprayed paint film and damage the sprayed paint film.