21 common construction problems and solutions for exterior wall coatings, pure dry goods!

There will be various problems in the construction process of exterior wall paint.

01 Slow drying and re-adhesive

After the paint is applied, the paint film has not dried for more than the specified time, which is called slow drying

Causes:

1.

2.

3.

4.

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Approach:

1.

2.

02 Chalking: the paint film becomes powdery after the paint is applied

Causes:

1.

2.

3.

4.
The paint is mixed with too much water when painting
.

Solution to chalking:

Clean the powder first, then use a good sealing primer to make the primer, and then re-spray the real stone paint with good weather resistance
.

03 Discoloration and fading

cause:

1.
The humidity in the substrate is too high, and the water-soluble salt crystals cause discoloration and fading on the surface of the wall
.

2.
The inferior real stone paint is not natural colored sand, and the base material is alkaline, which infringes the pigment or resin with weak alkali resistance
.

3.
Bad weather
.

4.
Improper selection of coating materials
.

Solution:

If you see this phenomenon during construction, you can wipe or shovel off the problematic surface first, let the cement dry completely, and then add a layer of sealing primer, and choose a good real stone paint
.

04 peeling and peeling

cause:

Due to the high humidity of the base material, the surface treatment is not clean, and the incorrect brushing method or the use of inferior primers will cause the paint film to detach from the surface of the base layer
.

Solution:

In this case, check the wall for leakage first, and if there is leakage, solve the leakage problem first
.
Then peel off the peeled paint and coniferous material, add durable putty to the defective surface, and then seal the primer to make the primer
.

05 Foaming

After the paint film dries, there will be blisters of different sizes on the surface, which is slightly elastic when pressed by hand
.

cause:

1.
The base layer is wet, and the evaporation of water causes the paint film to bubble
.

2.
When spraying, there is water vapor in the compressed air, which is mixed with the paint
.

3.
The primer is not fully dried, and the topcoat is painted when it encounters rain.
When the primer dries, gas will be generated to lift the topcoat
.

Solution:

Slight blistering of the paint film, after the paint film is dry, smooth it with sandpaper, and then make up the top coat; if the paint film blisters, the paint film must be removed cleanly, and the base layer should be dry and deal with the cause of the bubbling.
, And then spray real stone paint
.

06 Starting layer (also known as undercutting)

The reasons for the stratification phenomenon are:

When brushing, the primer paint is not completely dry, and the thinner of the surface layer swells the lower primer, causing the paint film to shrink and peel
.

Solution:

The coating construction must be carried out at the specified time interval, the coating should not be applied too thick, and the topcoat should be applied after the primer is completely dried
.

07 Sagging

At the construction site, it is often found that the paint sags or drips from the wall, forming a tear-like or corrugated appearance, commonly known as tears
.

cause:

1.
The paint film is too thick at one time
.

2.
The dilution ratio is too high
.

3.
Brush directly on the old paint surface without sanding
.

Solution:

1.
Apply a thin layer each time
.

2.
Reduce the dilution ratio
.

3.
Use sandpaper to polish the old paint surface of the brushed object
.

08 Wrinkles: The paint film forms undulating wrinkles

cause:

1.
The paint film is too thick and the surface shrinks
.

2.
When the second coat of paint is applied, the first coat has not dried completely
.

3.
The temperature is too high during drying
.

Solution:

In order to prevent this situation, avoid applying too thickly and brushing evenly
.
The interval between two coats of paint must be sufficient, and the second coat must be applied after the first coat of paint is completely dry
.
 

09 Existing cross-contamination is severe

cause:

During the construction process, the surface layer did not notice the distribution on the grid, which caused the shape to be out of rolling
.

Solution:

During the construction process, every construction step must be followed to avoid cross-contamination damage as much as possible.
At the same time, we can choose auxiliary coatings with anti-aging, high-temperature resistance and strong radiation resistance to fill, which can also ensure the reduction of cross-contamination
.

10 There is a lot of unevenness

cause:

The large area of ​​cement mortar causes slow drying time, which will cause cracking and hollowing.

Solution:

Carry out an even division treatment, and evenly match the mortar during the plastering process of the foundation house
.

11 It turns white when exposed to water, and has poor water resistance

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It is required to select paints with anti-ultraviolet, anti-aging, anti-sunlight pigments, and strictly control the addition of water during construction, and do not add water at will to ensure consistent color; in order to prevent surface pollution, apply a topcoat in time after 24 hours of coating completion
.
When brushing the top coat, pay attention to prevent it from flowing or forming a flowery feeling when it is too thick
.
During the construction process, the construction should be organized in accordance with the construction procedures to avoid professional cross-contamination or damage during construction
.

21 The yin and yang corner cracks

Phenomenon and main reasons:

Sometimes cracks appear at the yin and yang corners.
The yin and yang corners are crossed between two sides.
During the drying process, tensions in two different directions will act on the paint film at the yin and yang corners at the same time, which is easy to crack
.

Solution:

If the yin and yang corners of the cracks are found, use the spray gun to spray again thinly, and spray again every half an hour until the cracks are covered; for the newly sprayed yin and yang corners, be careful not to spray thickly at one time when spraying, and adopt a thin spray multi-layer method , The spray gun should be far away, the movement speed should be fast, and can not spray perpendicularly to the yin and yang angles, can only use scattering, that is, spray two surfaces, so that the edge of the fog flower sweeps into the yin and yang angles
.