Solutions to Common Problems of Waterproof Coatings

During the use of architectural waterproof coatings, various qualitative changes will be caused due to improper storage methods or incorrect construction methods

Storage lesions and treatment methods

After the waterproof coating enters the site, if it is not applied immediately or the production date of the waterproof material is far away from the entry time, the following qualitative changes may occur

precipitation

Pigments sink to the bottom and can no longer disperse paint online at coatingol.

(1) The paint is not stirred or shaken enough during the storage period;

(2) Stored for too long or the temperature is too high;

(3) Improper dilution or dilution with inappropriate materials

crust

During storage, the waterproof coating will form skin in the container because the container is not airtight and the storage environment temperature is too high

(1) Avoid unnecessary opening of paint buckets;

(2) Ensure the airtightness of the container;

(3) Store according to the specified appropriate conditions

Viscosity reduction

If the viscosity of JS waterproof coating decreases and produces peculiar smell during storage, it means that bacteria have degraded the ingredients and other thickeners in the raw material.
At this time, the coating has deteriorated and should be discarded
.

Diseases and treatment methods during construction

Slow dry and stick back

After the waterproof paint is brushed, the paint film still does not dry after the specified time, which is called slow drying
.
If the paint film has been formed, but there is still a sticky finger phenomenon, it is called back sticking
.
The reasons for this are as follows:

(1) The paint film applied by brushing is too thick;

(2) The second coat of paint has not been dried before the previous coat;

(3) Improper use of drier;

(4) The surface of the base layer is not clean;

(5) The surface of the base layer is not completely dry
.
The treatment methods are: (1) For slight slow drying and sticking back, the ventilation can be strengthened, and the temperature can be appropriately raised; (2) The paint film with serious slow drying or sticking back should be washed with strong solvent and repainted
.

chalk

After the paint is applied, the paint film becomes powdery
.
The main reasons are:

(1) The weather resistance of the coating resin is poor;

(2) Poor wall surface treatment;

(3) The temperature during brushing is too low, resulting in poor film formation;

(4) Too much water is added to the paint when painting
.
The solution to chalking is to clean up the powder first, then use an oil-based sealing primer with good performance as a primer, and finally apply two coats of interior and exterior wall coatings with better weather resistance
.

discoloration and fading

Discoloration or fading on the paint film is due to:

(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 base material is alkaline, which damages the pigment or resin with weak alkali resistance;

(3) Bad weather;

(4) Improper selection of coating materials
.
If you see this phenomenon during construction, you can first wipe or shovel off the surface in question, let the cement dry completely, and then add a layer of water-based or oil-based sealing primer
.

peeling and flaking

Due to the high humidity of the base material, the surface treatment is not clean, and the brushing method is incorrect or the use of inferior primer will cause the paint film to detach from the base surface
.
In this case, you should first check whether the wall is leaking.
If there is leakage, you should first solve the leakage problem
.
Then, peel off the peeled paint and loose materials, add a durable putty on the faulty surface, and then use an oil-based wall sealing primer to make a primer
.

blister

After the paint film is dry, there will be bubble points of different sizes on the surface, which can be slightly elastic when pressed by hand
.
The reason for this is:

(1) The base layer is wet, and the evaporation of water causes the paint film to blister;

(2) When spraying, there is water vapor in the compressed air, which is mixed with the waterproof coating;

(3) The primer is completely dry, and the topcoat is painted again when it encounters rain.
When the primer is dry, gas is generated to lift the topcoat
.
The treatment method is: slight blistering of the paint film, it can be smoothed with sandpaper after the paint film is dry, and then the topcoat is repaired; more serious paint film blistering, the paint film must be removed, and the base layer must be dry.
The cause of the blister is dealt with before painting
.

Sagging

On construction sites, paint can often be found sagging or dripping from the walls, forming a tear-like or wavy appearance, commonly known as teardrops
.
The reasons for this phenomenon are:

(1) The paint film is too thick at one time;

(2) The dilution ratio is too high;

(3) Brush directly on the unpolished old paint surface
.
The solution is:

(4) Coating multiple times, each time with a thin layer;

(5) reduce the dilution ratio;

(6) Sand the old paint surface of the object being brushed with sandpaper
.

wrinkled

The paint film forms undulating wrinkles
.
The reason is:

(1) The paint film is too thick and the surface shrinks;

(2) When the second layer of paint is applied, the first layer has not dried completely;

(3) The temperature during drying is too high
.
To prevent this, avoid applying too thick and brush evenly
.
The interval between two coats of paint must be sufficient, and it is necessary to ensure that the first layer of paint film is completely dry before applying the second coat
.

layer up

Layering is also known as biting the bottom
.
The reason for the layering phenomenon is that the primer is completely dry when brushing, and the thinner of the surface layer swells the lower primer, causing the paint film to shrink and peel
.
The solution is the same as the method to prevent wrinkles, the coating construction must be carried out at the specified time interval, the coating should not be applied too thickly, and the topcoat should be applied after the primer is completely dry
.