Recurring stain on newly painted ceiling
by Phil Cheers
I applied a white emulsion (latex or water based paint) to a freshly plastered ceiling, which had been `sized` with no problems. There was a frieze spot between the ceiling and a picture rail that I cleaned and applied a white emulsion paint.
After the emulsion dried a brown stain started showing which looked as if the emulsion had reacted with something underneath it. I lightly sanded and washed the area prior to repainting it but the stain still appeared...??