The base is too dry, the water absorption rate of the wall is too high or the base with high cement grade is easy to produce bubbles.
The base is too rough and not polished, and the wall batch speed is too fast in the process of putty construction, which makes the putty layer not in close contact with the base and forms an interlayer; A batch of putty is scraped too thick and bubbles easily.
The moisture content at the grass-roots level is too high and the density is too large or too small. The putty is rich in gaps, high in moisture content and airtight, so it is easy to make the lower part of the putty powder layer contain air during construction, which is not easy to be discharged, so it is easy to foam.
But after a period of construction, it burst and bubbled, which was mainly caused by uneven mixing of putty powder. The mud with uneven stirring contains powder particles that cannot be dissolved in time. During construction, the wall surface was not too bad to be painted, but after a while, the powder particles began to absorb a lot of water and then expanded and burst. As a result, the surface of the putty layer bubbles.
Solution:
Grass-roots treatment should be clean and smooth. If necessary, brush a layer of interfacial agent for surface treatment, and emulsion type is better for environmental protection.
After the putty powder is stirred evenly, let it stand for about 10 minute, so that all the ingredients are fully wetted and dissolved, then stir it again with an electric mixer, and then go to the wall.
During the construction of putty, it should be scraped repeatedly on the wall surface to make the putty fully contact, wet, permeate and diffuse with the grassroots.
If bubbles appear on the second or last surface of the construction, the bubbles should be broken with a scraper before the watermark is removed to ensure that no bubbles appear on the surface of the putty.
If there is a large area of foaming putty surface, directly crush the small bubble nozzle with a shovel and re-smear the foaming surface with inner putty.