What is the difference between the composition of decorative plaster and other similar mixtures?
Let's start, as usual, from the very beginning: how to prepare this or that plaster solution. Cement-sandy practically does not differ from the mortar for bonding bricks, the ratio of cement, sand and water varies, but the first two components are usually mixed in a ratio of 1 to 3.
Based on this composition, a cement-lime mortar is made, although the proportions when addingLime dough in the amount of 0.2 to 1 part significantly change - the sand is then put more, from 4 to 6 parts. If you do not use cement, you will get a clear lime solution, and if you add gypsum to it, the name of the plaster will change to the corresponding one, derived from the main constituents.
In principle, all of the above is sufficient to have an idea of the percentage ratio of constituent plasters and their components. Decorative plasters are manufactured in approximately the same way. As for the main ingredients, the decorative plaster usually includes the main binding elements - cement or lime.
Gypsum as a main component is rarely used due to the fact that this composition freezes in the next 10 minutes, which creates some difficulties when working with it .In addition to the base composition, fillers are used, among which sand, marble dust, cellulose fiber, as well as various plasticizers, antifoams, pigments, determining the properties of the plaster.
What consistency should the composition of the plaster solution have?
How well the solution will lie on the wall, and how much it will last there, determines primarily its viscosity. In this case, it should not be excessive, otherwise the plaster will roll down during application, but will not be distributed evenly by a uniform layer.
Therefore, adding the next components in the solution for plaster, watch for its density. It is best to knead and test the mixture with a special meter-long paddle, lifting it from the mass, you will immediately see how good the mixture is. For machine plastering, the mixture should be slightly lighter than for manual plastering.
If the plaster strongly adheres to the oar, it is desirable to add a filler to it, which is usually sand. If, on the contrary, the solution does not stick at all, it is necessary to introduce into it an astringent component - cement, lime or gypsum. In general, the composition should be of medium fat content, so that only slightly, not too thick layer, adhered to the oar .It is not difficult to prepare such a plaster composition with your own hands, it is enough only to mix the necessary components from time to time to the required proportion.
Composition of Venetian plaster and what are complex solutions of
The price of building material depends primarily on its composition, and not always natural components contribute to the rise in price. Take for example the composition of the Venetian plaster. The main binding element in it can be lime or a synthetic component. The simplest option is a hydrated lime with marble flour, vegetable dye and water as a diluent, is much cheaper than a synthetic analog.
Decorative plasters, including Venetian, are water-based or with epoxy resins as bonding elements.
If, however, you prefer a more expensive mixture with synthetic fillers, keep in mind that( God forbid, of course), if there is a fire, the resin plasters begin to decompose with the release of harmful substances.
For example, epoxy resins at 140 degrees chlorine, and polyurethanes - cyanide. Therefore, despite all the advantages of synthetic additives providing better viscosity and plasticization, try to adhere to the natural fillers that make up the mixture for the plaster.