Why do we need a primer: technological nuances of finishing work
Do I need to primer GKL and screed, performed by the plaster method, and how much primer is needed per 1 m2?
In finishing technologies associated with wet processes, surface treatment with soil is mandatory. This should be known to everyone who plans to make repairs with their own hands, or to finish new housing.
We hope that the video and a small instruction in this article will provide answers to these, and many other questions, of interest to our readers.
The content of the article
In what cases is soil needed
The quality of the performance of many types of work depends entirely on the soil - it is he who provides the maximum adhesion of the layers (adhesion). Everyone, probably, had to see the stucco falling off in pieces; wallpaper (seeWallpaper decoration: choose the right one), which are removed from the wall without much effort; or as in the picture below, peeling paint from the base.
So:
- Such situations arise when, when performing rough and finish finishes, the necessity of applying the primer was simply neglected. Exfoliation can occur quite quickly, immediately after completion of work.
A problem may appear after some time. In any case, such a coating will not last long, and sooner or later it will be necessary to redo everything. - But the price of a universal primer is low, in the range of 200-250 rubles per 5l canister. This amount is enough to process almost 50 squares of the area in one layer (seePrimer consumption per 1 m2 - approximate data for determining the required volume).
The process of applying the soil does not take much time either, so there is no reason to try to save on it. On the contrary, this primer, reducing paint consumption, will save your money and save you from unnecessary problems.
- Now on sale there are such paints that are also primer at the same time, and this is confusing for many. In this regard, readers have, for example, the following questions: "Using acrylic paint, do I need to prime the base?", Or: "Do I need to prime the bark beetle before painting?"
- The answer to these questions should be unequivocal: of course it is. Without additional treatment of the base, the paint primer can be used on metal and wooden surfaces.
Usually these are alkyd paints, but for wall decoration and ceilings, they do not fit. - Here you need a water-based composition, and one of the options you see in the photo below. In fact, this is pigmented soil, and the purpose of its application is to tint the base in white.
In some cases, it is necessary to do this: for example, if thin-layer plaster, such as Venetian or decorative paint in one layer, is applied. There are other situations.
- For example, in a panel house, the walls are fairly even, and you do not need to level them. It is quite possible to glue wallpaper on them right away, but if they are thin and light, a dark concrete base will be visible under them.
In this case, the water-dispersion primer with white pigment, which you see in the photo above, will eliminate the need to putty. So to say, "two in one." - The concentration of pigment in such a soil is low. If it is used as a full-fledged paint, then in order to achieve the necessary intensity of the shade, it would be necessary to apply many layers.
This, as you know, is not practical.The painting of walls and ceilings in residential premises is mainly carried out with latex and acrylic paints.
In this regard, readers most often ask the following question: “Do I need to primer acrylic paints?”.
The answer is: it is necessary to do this. But, if you are going, for example, to paint the ceiling in traditional white color, the use of pigmented soil will make it possible to do with one coat of paint instead of two.
Types and purpose of soil compositions
Now we will tell you a little more in detail what are the soil compositions. Indeed, some of them can be made independently - which is often done by professional builders and homegrown craftsmen.
So:
- Today, few are already using lime to whitewash a building, at least in cities. In general, the basis for such coloring is also required to be primed, and the composition is used as follows: 2.5 kg of 50% lime dough and 100 grams of table salt or alum are added to 10 liters of water.
- When you need to whiten a previously painted surface with lime or chalk solution, you need a glue primer. In this case, 250 g of household soap is rubbed onto 10 l of water, 200 g of copper sulfate is added, and the same amount of PVA glue (you can use carpentry glue).
- This type of primer is often used when painting industrial premises. After all, they have huge areas, and the compositions sold in cans are simply impractical to use in such cases.
- Under adhesive paints, the composition is different. For the same volume of water, you need 400 g of soap and glue, plus 200 ml of natural drying oil. The base for silicate paint is primed with a solution of liquid glass and chalk, at the rate of 10: 1.
- As for prefabricated soil compositions, each of them also has its own purpose. Impregnating primers are intended for processing plastered, brick and concrete surfaces, and are used before applying water-based paint or wallpaper glue.
- They fill the pores, forming a transparent colorless film on the surface of the base, and are consumed in the range of 100-150g / m2. At normal room temperature, the soil layer dries in one to two hours.
- If the surface of the base is unstable, for example, old brickwork, and it needs to be strengthened, deep penetration soil is used. Such compositions have anti-corrosion properties, stopping the destruction process in the thickness of the structural material.
- Impregnations intended for wooden surfaces can protect them not only from decay and the formation of mold and fungi (seeAntifungal primer - purpose and characteristics of the material), but also from rodents. They are applied two to three times, with intermediate drying, and grinding the top layer with felt or felt.
- For mineral plasters, which include the notorious "bark beetle", also has its own type of soil.
This composition regulates the absorbency of the base, provides uniform drying of the layers deposited on top of it. A pigment can be added to it, as, as in the case with painting, to prepare the desired color shade.
As you can see, soil compositions play an important role in the technology of finishing work. It remains only to add that they are applied to a clean and dry surface, at plus temperature.
This is done in any way convenient for you: brush, roller, or spray gun. If the surface is plastered, then in addition to the base, each applied layer should be primed.
