Casein

Casein glue

Casein glue is a binder and adhesive of organic origin (cheese, milk egg white) The Egyptians used it to glue their wooden chests, and later it was widely used as a color binder. Casein is extracted from milk, which is an emulsion consisting of water, fat, milk sugar and various salts. After recovery, the casein is "washed" thoroughly with water to remove any water-soluble substances. The casein is pressed, dried and crushed into a powder form.

Casein is used for the production of eg glue paint, lime casein paint or tempera.

Casein is in itself completely insoluble in water. The actual casein glue is only formed when the casein is added to alkalis, such as, deer antler salt, ammonia water, borax or slaked lime and mixed with water. By adding color to such a solution, a casein glue color is obtained.

Casein color is transparent immediately after application, but dries beautifully, matte evenly.

Casein can also be added lime color, thereby increasing the bonding strength of the lime and a stronger surface is obtained. Lime casein is therefore usable on surfaces where the lime does not bind as well as, for example, concrete, trusses, on cement plaster or on plinths. By adding casein, however, the lime is transformed from mineral color to glue color and some of the lime's antiseptic, moisturizing and self-cleaning properties are lost and are therefore recommended primarily for areas where the lime has difficulty binding.

By adding casein to the lime outdoors, it is also achieved that the lime can bind more dry matter, so that you can get a stronger hue.

Casein glue is open to diffusion and binds on most substrates, even plastic paint.

Areas of application

Indoors, casein glue is typically used for glue paint, where you want a stronger surface than glue paint based on carrageenan or cellulose. On woodwork, for example visible ceiling boards, casein paint even has the advantageous property that the knots in the wood do not penetrate the paint layer. The paint insulates for the resin rash, so you do not need to treat with cam varnish before painting the surface. Casein glue paint can be used both outdoors on planed wood and plaster, and indoors on plaster, base paper, plasterboard or wood.

compatibility with other binders

Together with oil and oil varnish, casein glue can form emulsions, as in tempera. Addition of casein glue to plant glue makes the latter more adhesive strong.

compatibility with pigment/colors

Casein glue can only be used with all pigments, but if the casein glue is used for the production of lime casein dyes, the pigments must be calcareous.

Drying

Dries by the water evaporating, the actual hardening only takes place after a long period of time. Lime casein becomes water insoluble after drying.

Weather resistance

Lime casein is quite weather resistant. Approx. 5-10 years.

Storage

Powdered casein should be stored dry and cool.

Safety

Casein is described as non-toxic.