I'm working right across the street this week, literally. I am removing PBV from a two story hall, dining room and kitchen. I remember this job that I did in 1994. I had just started using Muralo 8900 Wall Protecting Primer (gold can.) The house built in 1987 had extremely crappy builder's flat. I did a one coat of 8900 everywhere at the time.
Hall and DR came off like a dream. But the kitchen was tougher. I recall that I had had to remove a vinyl coated paper in 1994 before hanging the new. There was no primer underneath that paper...it was hung directly on garbage. I suppose I washed it down the best I could at that time before priming with 8900.
What happened this week is that I sprayed the paper backing and after the backing was wet for more than 5-10 minutes apparently the removal solution was making its way to the garbage paint thereby loosening the foundation of the 8900.
Having sat through many an hour of paint rep talk at the BCM one thing I have learned about paint is that two coats are better than one especially when water is an issue. When paint dries there are all sorts of pinholes in the coating for various reasons. When a second coat is applied there are also pinholes but due to the randomness of them the pinholes of the top coat do not line up with the pinholes of the botome coat. This renders the two coat job more impervious to water no matter what the "perm rating" of a paint is.
IMO when the pores of very porous garbage paint is loaded with paste that dries, it is impossible to fully "clean" this surface no matter how much water is used. For this reason as of 2011 I am going to change my procedure for this type of situation and "first coat" prime with Gardz and second coat it with a white acrylic.
