During the coating process of architectural coatings or during the period of use after coating, the coating defects are generally related to the state of the object to be coated, the coating process, the type of coating, the coating method and operation, and the coating environment and other factors. The common disadvantages of architectural coating coatings include sagging and flowing, exposed bottom, poor hiding power, brush marks, cracks, cracks, peeling, fading and blooming, etc. The specific causes and prevention measures are as follows:
cause:
1. The density of the coating is high, and the coating contains pigments and fillers with high density.
2. If the coating is too thick, the difficulty of sagging and flowing is proportional to the third power of the coating thickness.
3. The viscosity of the coating is too low or the stirring is uneven.
4. The temperature of the construction environment is too low, the humidity is high, and the paint dries slowly.
Precaution:
1. Properly adjust the formula, and use caution with high-density pigments and fillers.
2. Strictly control the thickness of the construction coating, according to the construction requirements of different coatings, not too thick.
3. Control the construction viscosity of the coating. Different types of coatings should be constructed according to their required viscosity.
4. The temperature of the application environment should generally be kept above 10°C, and the relative humidity should be less than 85%.
cause:
1. The pigment content in the paint is too low and the filler content is too high.
2. The paint is not evenly stirred.
3. The viscosity of the paint is low and the paint is too thin.
4. The color difference between the substrate and the paint is too large.
Precaution:
1. Properly increase the amount of pigment used, and adjust the ratio of pigment and filler.
2. Fully stir the paint before and during construction to make it even.
3. Appropriately increase the amount of thickener to achieve product viscosity. Careful operation should be performed during construction to strive for uniform thickness.
4. When the color of the substrate is too dark and the color of the paint is too light, the process of painting the paint can be appropriately increased or the amount of pigment in the paint can be increased.
cause:
1. The leveling property of the paint itself is poor.
2. Brushes and rollers are hard.
3. The pigment/binder ratio of the paint is not suitable, and the content of pigment and filler is too high.
4. The base material is too dry and the construction environment temperature is too high.
Precaution:
1. Use organic thickening rheology agent with good leveling property to improve leveling property.
2. Select the appropriate brush and roller according to the paint used
3. Adjust the pigment/binder ratio of the paint and increase the amount of base material.
4. Apply back-sealing liquid to the base material, and avoid construction under high temperature conditions.
cause:
1. The base layer has not been properly treated, with dust, oil, etc.
2. The base material used in the coating is too little or the amount of film-forming aid is not enough.
3. The construction temperature is too low and the coating is too thick.
4. Apply the top coat before the base coat is dry.
Precaution:
1. Handle the base layer according to the construction specifications.
2. Increase the amount of base material or film-forming additives to ensure that the base material used can form a film at the construction temperature.
3. The construction temperature is preferably above 10°C, and the coating thickness is strictly controlled according to the process requirements.
4. The base coat needs to be dried before the top coat can be applied.
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