Good day.

A lot of information available on the net; but seems the surfaces where it can be applied is missing details. What have you experienced or can comment/supply guidance ?

Read the surfaces to apply can range from bare concrete block walls; bare brick; old deteriorated paint of several types as latex, colors that may bleed out, oil based, limewash... After nail holes are filled, preparing white Portland cement plus water and nothing else to the consistency of 'toothpaste' and applying with paint roller, brush, scraper?, to a smooth finish that will even and cover irregular lines.

My specific case is 80 year old plaster walls with the corresponding scars and portions where painted layers have detached or turned dusty. (After wallpaper removed 🙄)

What white Portland cement paste paint would not stick to ? (obviously clean)

Recommended tools other than wide 'putty knives' for smooth finish application ?

Or, mixing it with paint for better color blocking ? I understand 'primer' paint does not fill hairline cracks, white cement paste would be much different ? Can it be painted over after set ?

Educate me, please.

Search 'portland topper coat'.

I've seen some beautiful work with stucco, which is the same mixture plus clean sand. Not on interior walls, though, only exterior, mainly because it's weather resistant and has a bit of texture to it.

Anything concrete is going to have some problems with cracking when the house shifts inevitably. Fortunately, it's a pretty inexpensive solution to maintain.