How to use cracks correctly
- 2019-06-24-

The crack lacquer process is to spray a crack topcoat which is obviously different from the color of the primer on the surface of the object to be coated. When the crack topcoat is formed into a film, due to the rapid evaporation of the solvent, the inside of the paint film may have a large crack due to volume shrinkage. At this time, an irregular crack gap appears on the surface of the coating film, so that the underlying color different from the color of the crack topcoat is revealed in the crack gap, thus forming the beautiful crack-like shape we need. Pattern.

But if the crack is too fine and even the crack is not cracked, what should we do?

Generally, since the crack pattern is formed by the cracking of the paint film, it cannot be sprayed too thick at one time, otherwise the crack will be fine or even the crack surface will not crack, and the oil amount should be carefully controlled to select a suitable pattern. Since the crack paint is sensitive to temperature and humidity, if the temperature is too low, the crack is small or not cracked; if the temperature is too high, the pattern is large. Therefore, when the ambient humidity is too high, the temperature is too high, and the temperature is too low, it is not suitable for construction. Generally, the temperature is 25 ° C, and the relative humidity is 75%, so as to avoid adverse effects. In addition, due to insufficient understanding of the basic characteristics of cracked paints, the use of non-nitro-based paints (including aluminum powder, pearl powder, gold powder and other colored primers) in the construction of the base primer caused the crack paint to be ineffectively blended with the primer. And show another crack characteristic. The solution is very simple. For the non-nitro-based paint primer (including aluminum powder, pearl powder, gold powder and other colored primer), spray nitro varnish 1-2 before spraying crack paint, etc. -20 minutes or so (depending on the ambient temperature) When the nitro varnish is in a semi-dry state, spray the crack paint once, and the crack effect can be produced.

First, try to make the bottom of the two-component paint before applying the primer to the crack. Then, when the cover is light, the clear top coat is mastered and sprayed many times, and it can be divided into two times. Then the crack paint should be used up within 4 hours. Then the crack bottom should be selected from single-component coatings, mainly in NC type or specially equipped with crack bottom, the time interval should be consistent, and the displacement and oil output should be well grasped.

The viscosity of the paint applied by the spray cracking should be uniform, and the air pressure of the air compressor should be consistent, not large and small. The orifice diameter is 1.5 to 2.0 mm. The oil outlet should be smooth.

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