The free alkali in new lime and cement plaster rapidly destroys the oil in paint and prevents it from drying. For this reason it may not be possible to paint a plastered wall until 12 months after its completion and in such cases the wall should be white-washed in the first instance.
The walls should be primed with boiled linseed oil or glue size (glue mix with water); glue size should not be used if the walls have been white-washed. First two coats should consists of white lead and boiled linseed oil. Third coat can be of white lead tinted to approach the desired colour and mixed with raw linseed oil and a small proportion of turpentine. The finishing coat should contain a large proportion of turpentine with a little varnish to serve as a binder and applied when the previous coat is still tacky. This will give a flat finish as a glossy finishing coat shows up the irregularities in the plaster.
In the case of new cement plaster walls, a solution of 2 kg of zinc sulphate in 4 litres of water should be applied to the surface and when dry given a coat of pure raw linseed oil; (one part acid to 50 parts water) and the washed down with water. (Acids should be added to the water and not water to the acid).
Two coats of paint thinned with turpentine and having a little varnish as a binder should serve as first and second coat. Third coat paint should be thinned with a mixture of three parts boiled oil to one of turpentine. The finishing coat can be the same as for lime plaster walls.
Paints are now available in the market which can be applied directly on newly plastered walls.
