For improved adhesion of the base of the ceiling and finishing material, as well as for uniformly applying the coloring composition, it is necessary. When drying, the primer forms an inconspicuous film on the surface, which helps to repulse moisture and creates additional adhesion.
Primers can be universal, which perform several tasks. There are primers that are designed for a certain method of finishing. So for adhesive coloring, it is necessary to use a soil-moillar. To prepare such a composition, you need to configure 250 g of soap and dilute with hot water (liter). 300 g of dry glue are diluted with two liters. The prepared mixtures are mixed, after which you need to add 30 g of olifa, from one to three kg of chalk and a little more water to achieve the desired consistency. The composition is filtered. If a coupor primer is required, then copper sulfate is added to the resulting composition. For this, 150 g of sulfate is diluted in hot water (liter).
If the ceiling should be painted with oil paint, then the base of the ceiling is treated with an Oliph. Before applying to the Olifa, you need to add dry pigments or grated paint their amount should be 10% to the bulk of the olifa mass. For better absorption, the olifa warms up.