knauf easy sand over existing painted surface

[Donzo]

Hi guys' filled a joint on ceiling that customer had existing vinyl silk paint on,once dry sanded. Customer painted it a month later and it bubbled. They painted it with matt paint. Did I get it wrong by not using a setting compound or should I have sealed it before hand.I often touch up painted drywall and do not want to be making this mistake again if its my fault. :RpS_confused:

 

[Trevthespread]

Sorry did the paint bubble or the filler.

 

[Donzo]

Hi,it was the paint. I asked was it watered down. They replied no.I think the paint was too strong,but a decorator said to me if he was using filler over a painted surface he would PVA it. I don't agree but if I'm wrong then I can change method in future.