Blistering Matt emulsion paint.

[rockingrodders]

Hi. Just prepared a room for painting. Removed all the loose flaky paint, then filled in as necessary, sanded down the entire wall areas, washed with sugar soap then clean water.
When I painted with a crown Matt emulsion the paint immediately started to blister with air bubbles some of which disappeared but many didn't. The resulting finish is a wall covered in small blisters.
Any suggestions as to why this happened and how to overcome it, before I go any further as I stopped after 1 wall.
Thanks

 

[joe-90]

You need to spot prime the filler with watered down emulsion.

 

[rockingrodders]

Thanks Jo. But it's not just where the filler is. It's pretty general all over. I didn't water down the first coat because it had previously been painted and it was only a couple of spots that needed filling.