Source Lei powder tell you "why can't interior wall paint be used for exterior wall"!

Release time:

2024-01-29 09:38


Source Lei powder tell you "why can't interior wall paint be used for exterior wall"!


Interior wall paint

Why can't it be used for exterior walls?

Water-based interior wall coatings are composed of water, emulsion, pigments and fillers, additives, interior wall coatings and exterior wall coatings are different because they are not the same as the environmental resistance. Generally speaking, outdoor coatings need to have certain resistance to wind, frost, rain, snow and sunshine (water resistance, alkali resistance, UV resistance, frost resistance, fading resistance, pollution resistance, etc.), so the requirements of the selected raw materials in the formula are higher than those of interior wall coatings. The environment experienced by the general interior wall paint is more moderate than that of the exterior wall, so the general interior wall paint can not be used for the exterior wall.

exterior wall paint

Can it be used for interior walls?

The performance requirements of exterior wall coatings are higher than those of interior walls. Of course, exterior wall coatings can be used for interior walls. Because the price of exterior wall coatings is higher than that of interior wall coatings, the general consumers do not use them, but sometimes when the requirements for interior wall coatings are more stringent or have special requirements, exterior wall coatings can be used, such as bathrooms, toilets, kitchens and interiors, to make them more magnificent.

Before painting

Are there any requirements for wall humidity and wall maintenance period?

The wall is wet, on the one hand, the moisture in the cement or mortar that has just been constructed has not completely faded, and on the other hand, the environment is too wet or rain causes excessive humidity. The wet wall will affect the adhesion of the coating surface, which will cause the coating surface to blister, crack, fade and promote the growth of mold. And in the process of water evaporation and drying will make the wall salt alkali exudation and accumulation on the surface, it will damage the coating surface and make the color fade. Therefore, the humidity of the wall before construction is limited to less than 6%.

There shall be a curing period of at least 28 days after the cement wall is formed and plastered, so that the cement is completely cured, dimensionally stable and the wall alkali is seeped out and cleaned before painting.

Surface treatment

How many ways are there?

No matter how high the quality of the coating used, if there is no adequate and proper surface treatment in advance, the resulting coating surface will not be perfect in performance and efficiency. The surface treatment varies depending on the substrate, but the purpose is the same, that is, to give a dry and stable substrate.

Surface treatment methods: high-pressure water washing, grinding, temperature control, required substrate maintenance period, shedding, pickling, solvent degreasing, sawing, sandblasting, repair, etc.

Water-based interior wall paint with high viscosity

Can direct spraying?

High viscosity of water-based interior wall coatings, not diluted or a small amount of dilution, can be directly sprayed with airless, and the effect is better. If the use of air spray, the water-based interior wall paint must be diluted to the corresponding viscosity, because different spray guns, different air pressure, the viscosity of the water-based interior wall paint required. Water-based interior wall coatings require large spray gun paint volume and fog width, and large spray width.

How to choose a brushing tool

Use should pay attention to those problemsWhat?

According to the size, nature and paint material of the painted surface, different bristle brushes and pens are selected. The primer and blending paint shall be applied with flat bristle brush; the varnish shall be applied with flat brush with thinner bristles and better elasticity; the bristle brush has greater elasticity and strength than the pen, and is suitable for painting with higher viscosity.

When using a new hard brush, before painting, the hard brush should be placed on No. 1 sandpaper, and the head of the bristles should be sanded back and forth. After the bristles are polished smoothly, a small amount of paint should be dipped on the surface of the old object, and the bristles should be brushed back and forth several times to make the floating and broken hairs fall off, so as to ensure that the bristles do not fall off easily during brushing.

When using a new pen, in order to reduce hair loss, before use, use your fingers to move the pen hair back and forth to make the unglued wool fall out, then soak it in hot water, smooth the pen head, and wrap it with paper to dry itself.

When water-based interior wall paint is applied

Brush more than twice?

The water-based interior wall paint is painted twice mainly in order to achieve its due hiding power and coating surface performance. Because the hiding power of the coating and the surface performance of the coating have a certain relationship with the thickness of the coating surface, in order to achieve the best decoration and protection effect, the water-based interior wall coating is best painted twice. The premise is that the construction is carried out in accordance with the substrate treatment and dilution rate required by the instructions.

After the water-based interior wall paint is brushed once

How long can be recoatedWhat?

The interval time between two times of water-based interior wall paint brush shall be determined according to the specific construction conditions. The main thing is to apply the second time after the first time is all dry. Some coatings dry slower will extend the recoating time.

Apply a thick layer

Can achieve the effect of coating thin two layersWhat?

Water-based interior wall coatings are generally required to be coated twice (under normal dilution). Too thick coating will cause cracking on the surface of the coating, and the appearance and leveling will not be good. Although the formulation is designed to consider the condition of the thicker coating surface, it does not mean that the water-based interior wall coating can be overdiluted and brushed many times, because the excessive dilution of the water-based interior wall coating will cause the coating surface to powder.

After the batch of putty

How long does it take to paint?

There are many putty suitable for building walls, mainly water-based putty and nitro putty. If it is water-based putty, it should be brushed after 24 hours. If it is nitro putty, it should be brushed after 5 hours. The specific basis is to brush the coating after the putty is dry, otherwise the coating surface is easy to bubble and peel.

  • a. How should substrates such as gypsum board and asbestos cement board be treated?

Gypsum board, asbestos cement board should be fully dry before brushing the surface, because they have a certain degree of alkaline, it is recommended to use the first layer of sealing primer after finishing paint.

  • B. does it affect the old wall not to brush primer when painting water-based interior wall paint? how should the wall be handled?

If the old wall surface is relatively strong and the wall alkali is not serious, you can sweep the wall surface and brush the topcoat directly. If the coating surface is loose and the surface is uneven after shoveling, the putty shall be re-approved and the primer shall be used to ensure the quality of the topcoat.

Tell, paint, interior wall, brushing, water-based, surface, putty, requirements, wall, dilution

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