Nowadays, exterior wall coating is mostly used for decoration. Some problems such as peeling, blistering, bursting and discoloration appear on the wall, which reduces the beauty of the exterior wall. In addition to the quality problems of the coating itself, part of the reason is due to inadequate understanding of the primer or improper use
Problems such as peeling, blistering and bursting caused by base course pulverization, putty desalting, insufficient adhesion between coatings, poor sealing of base materials, etc. due to improper alkali resistance treatment of base course, pan alkali discoloration is caused by not brushing the primer, which causes base course blooming, which is caused by excessive water absorption of base course or uneven application of primer, resulting in poor film formation of top coat, and the blooming engineering is inseparable from the primer, Understand sealing primer, select primer to avoid these hidden dangers.
The function of applying alkali resistant sealing primer
No matter cement plastering or thermal insulation and anti crack mortar base surface of building exterior wall, the interior is mainly composed of cement, and the alkali content in many cement is relatively high. If the primer is not painted in place, or even the primer quality is not good, it will cause serious alkali returning phenomenon. Alkali branch will quickly corrode the coating film of exterior wall paint, causing quality problems such as fading, differentiation and cracking.
The biggest characteristic of alkali resistant sealing primer is that it has strong adhesion to concrete and can form a good sealing area with concrete. It is mainly used as the base material protective material of concrete. It can prevent water penetration, resist alkali isolation, effectively isolate the alkali in the base layer, and prevent the alkali from seeping out and damaging the coating. The loose and powdered basement is reinforced to strengthen the basement.
The importance of applying alkali resistant sealing primer
1. Sealing effect: cement is generally used for wall surface, and the cement will return to alkali, forming a layer of alkali frost on the surface, forming flakes of white or crystalline or powder, etc., resulting in flower wall. The basic reason for the appearance of Pan alkali is that the primer quality is not up to standard or the primer is not used or the putty wall is too alkaline. Other changes such as yellowing or color change are mostly related to this. Sealing primer can play a sealing role and alleviate this situation.
2. Ensure the same water absorption: the water content of the base must be paid high attention to, especially the same wall may be made of different materials, and the base materials with different water absorption will cause watermark or color difference in the final finish of the exterior wall coating. The safe and reliable prevention method is to fully coat the alkali resistant sealing primer produced by professional manufacturers before construction, so as to make the water absorption of the base uniform and consistent. In addition, the inconsistent water absorption of the substrate will lead to the inconsistent drying time of the coating, uneven absorption and color difference.
3. Wall firmness: the putty layer with poor quality will be powdered soon. If there is no primer protection, the surface layer will also be powdered or even fall off. The primer can seal the base, make the putty layer more firm, thus prolonging the service life of the surface layer and improving the construction quality.
How to choose alkali resistant sealing primer
Primer can be divided into transparent primer and black primer. Then, how to choose transparent primer and black primer? These two colors
What are the differences between different primers?
The main difference between the transparent primer and the black primer is the division of the wall. If the wall is divided into large divisions or not, the transparent primer should be used. If the wall is divided into large divisions, the black paint should be used to trace the line. If the wall is divided into small divisions, the black primer should be used.
As a user, it should be clear that the comprehensive performance of transparent primer is better than that of colored primer. A simple understanding is that colored primer is based on transparent primer, adding color paste of various colors, and the color paste itself only plays a role in changing the color. A certain amount of color paste will be included in the primer, which will reduce the performance of the product itself. Therefore, when selecting materials for the project, the construction unit should be specified as much as possible Transparent sealing primer shall be selected.
Construction guide of exterior wall sealing primer
1. Before the construction of exterior wall primer, certain maintenance shall be carried out for the exterior wall, and the wall shall be leveled as far as possible, without too obvious pits and bulges, or cracks and other hard injuries. After these are almost complete, the construction shall be started again.
2. When the primer is applied on the outer wall surface, the function of the primer is very important. It has a strong bonding ability. It can seal off the alkaline of the wall surface, so that the primer of the outer wall can be bonded firmly during construction. It can also integrate the ash layer and the putty bottom, which greatly improves the waterproof performance of the outer wall. Moreover, it can save the coating and make the coating more uniform, The final result will be very good.
3. After these finishes, the finishing coat can be applied, but before that, check whether the primer is missed or polluted. After these finishes, the first finishing coat can be applied. The finishing coat shall be applied evenly and in the same direction.
Sealing primer is just like the foundation of a house, which plays an important role in the coating system of exterior wall paint. Therefore, users should pay more attention to the material selection and construction.
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