Hi everyone, I stripped my old plaster walls, removing wallpaper, old paint, etc. This weekend I attempted to prime them, only I discovered that some of the primer wouldn't stick. Any idea what the problem could be? Someone I talked to said I should use the Original Kilz versus Kilz 2 (which is what I was using). What's the difference? Is one better than the other for old plaster walls? Another thought I had is maybe the primer didn't have anything to adhere to because the plaster is smooth. Could that be the case? Should I sand the wall before priming? My house was built in 1925. The plaster is 80+ years old. Any advice is appreciated.