How is the putty layer foaming and empty drums, how should it be handled?

The main reason is that the putty layer is hollowed and foamed. The main reason is that there is gas between the base layer and the putty layer, and why the air does not diffuse into the normal layer and diffuse into the base layer, but appears in the middle. The main reasons are as follows: : improper treatment of the base layer, so that the contact between the putty layer and the base layer is not tight enough to form an interlayer; there is a dense layer between the base layer and the putty layer, such as interface agent or wall solid without water for interface treatment, so that the air cannot diffuse normally to the base layer.

Solution:

If the wall bubble or empty drum is small, it can be treated by sanding and then treated with wall solidification, and then scraped; if the wall is large, it has caused large area to fall off, it is recommended to use all the walls after eradication. Solid treatment, then batch scraping.