Sgraffito plastering technique
Sgraffito is a colored decorative plaster consisting of a primer and two or more colored layers of a nakryvka on which a silhouette drawing is scratched. This plaster is mainly trimmed with architectural elements and facades of buildings. Sgraffito plaster is prepared from lime dough, pure quartz sand, pigments, cement (as an additive in the amount of 10 … 15%). To make graffito, we scrape the upper layers of the plaster or apply the plastic plaster mortar using stencil templates.
We prepare the surface for the application of sgraffito, then apply the primer that we scratch, withstand it before applying the coating, then moisten it with water.
The nakryvochny layer we smear or we throw. In order to avoid the formation of voids, all applied layers are carefully leveled and compacted. The first nakryvochny layer do in thickness not more than 5 mm, and the remaining color layers – 1 … 2 mm, they are sometimes applied with a brush, without applying poluterki. After 2 … 4 hours, when the color layers of the coating harden, the graffiti plaster is scratched with tools that have different shapes. After that, we brush over the entire surface with a brush or with a brush.
Portland cement, marble, granite or ceramic crumb, the fraction of which is 3 … 5 mm, is necessary for the preparation of decorative plasters with stone chips imitating hard rock. Using alkaline and light-resistant pigments (ocher, iron minium, etc.) and colored cements, we make colored crushed stone and mortar, from which we later obtain colored decorative plaster.
The technique of applying plaster sgraffito Decorative plaster arrange with spray and primer, aligning it carefully. Basting, made from a complex solution, we apply either under the rule, or at the beacons. For a better hitch covering with the ground, the last one is cut into grooves intersecting with each other. We apply the decorative layer on the dried preparatory layer. The solution of the finishing layer is applied to the dried soil moistened in advance with water from a sleeve or from an airbrush. Finishing the facades in sunny and hot weather, the surface of the plaster is covered either with wet bags or matting. After a day, the treated surface is flushed with water until clean water flows from the surface. By washing, we remove cement dust and create a clean surface with a pronounced tiny texture.
Sometimes we make decorative plaster from bastard, made from ordinary mortar without a stone crumb, which we apply to the ground with the help of mechanical or air crumbles. This increases productivity and improves the quality of the finish. The stucco and color solution should be of the same consistency.