Glue paints: features and applications

Glue paints are a group of paints based on organic adhesives (animal, bone, casein, carboxymethyl cellulose, gum arabic and others). Chalk, kaolin, iron blue, talc are the pigments and fillers.

Such paints are similar in properties to emulsion paints: they dry quickly, are vapor permeable, environmentally friendly, and inexpensive. However, they do not differ in water resistance (with the exception of casein). Therefore, they are mainly used for ceilings and walls. It is important that the room in which adhesive paints are used is well ventilated, otherwise the applied layer will begin to gradually deteriorate and mold may appear. For this reason, it is not recommended to work with this paintwork material in basements, warehouses, and they are used quite often for decorating residential buildings.

Glue-based paints are watercolor and gouache, well known to everyone, as well as glossy mica additives, which are great for decoration.

Casein paints

Casein paints stand out as a separate subgroup of adhesives due to the presence of some specific properties. It contains casein, alkali, phenol, and lime. Resistant to rainfall, moisture, very durable, therefore they are used for outdoor work on concrete and wooden surfaces. When applied, they form a matte surface and look very aesthetically pleasing.

How to apply

Finished formulations of adhesive paints are sold in the form of powders. The color scheme is diverse. Before painting, the base is cleaned of old paint, cracks and bumps are covered with gypsum, putty or fiberglass. Glue paints do not have elasticity, and existing defects will remain visible. If the surface is plastered, then it must be primed to improve adhesion.

For this purpose, solutions of copper sulfate or aluminum-potassium alum with the addition of drying oil and dry animal glue are used.
The powder is diluted with water in 1: 1 proportions and mixed thoroughly, lumps should not remain. The resulting solution is left to swell for 10-12 hours (for casein inks for 40-60 minutes, then strain) and add more water before use. The resulting mixture is used for 12-24 hours (less common are paints that can be used for two days). They work with a roller or brush, painting in two layers. When applying decorative elements use a rubber roller.

The advantage of adhesive paints is that although they are unstable to moisture, they can be washed off with water if necessary. The casein base is washed out with a solution of hydrochloric acid, vitriol primer.