How to deal with blistering and empty drum of the wall putty

Q: What causes blistering and empty drum of the wall putty layer and how to deal with it?
A: The main reason for the blistering and empty drum of the putty layer is the presence of gas between the base layer and the putty layer. The main reasons why the air does not diffuse to the surface and to the inside of the base layer as normal, but appears in the middle, are the following: improper treatment of the base layer, so that the contact between the putty layer and the base layer is not close enough to form a sandwich; the presence of a dense layer between the base layer and the putty layer, such as with glue, Jimbo or wall captivity without adding water The interface treatment prevents the air from diffusing normally to the grassroots.
Solution: If the air bubbles or empty drums on the wall are small, the wall can be treated by sanding and then treated with wall captives and then shaving ; if the drums are large and have caused a large area to fall off, it is recommended to remove them all and then treat them with wall captives and then shaving .