Renovating a living room with part of the wall consisting of plastered chimney and need to apply new plaster on top to smooth out/build up. Have torn down all the old wallpaper and wet/scraped away all remnants so the old plaster is exposed.
Now to the problem, twice the plaster has neither cured nor adhered properly. Thought the first time it was poor plaster mix and therefore added more cement. Have primed several times and even "painted" with cement-mixed water, but it didn't help. The plaster cured in places where the brick was visible.
Any input is valuable on what I can do to make it cure. The house is from 1946.
