Is it possible to put putty on different types of paint?

Many construction works are inextricably linked to this type of finish, as putty coating. And if it concerns a new building or premises, then often there is already a layer of paint on its walls. Then a logical question arises: is it possible to put putty on paint? The answer to it depends on what type of paint you are dealing with.

How to determine the type of paint on the walls

To determine the type of paint applied to the surface, a simple test is carried out - soak it with a sponge soaked in warm water. If it becomes covered with foam and begins to wash off, then this is a water-based paint, when applying putty under the influence of moisture, it will necessarily go off in layers.

Apply on such a coating putty meaningless, which means it will have to be removed completely. This is done simply: moisten the surface with a sponge or spray with ordinary water and leave it for 10-15 minutes. After that, the paint can be easily removed with a spatula, and wipe the surface with a damp cloth and dry.

If after wetting the color coating does not come off, then it is enamel based on drying oil or other non-aqueous solvents. Puttying on oil paint is possible after appropriate preparation, unless, of course, the painted layer holds well. To check this, scratch the surface with a metal spatula in several places. If the paint comes off in layers and falls off, it should be cleaned off.

Methods for removing paint from the wall

Distinguish the removal of the painted layer by chemical, thermal and mechanical methods. The first method involves the use of special compositions that soften the enamel to such an extent that it can be easily removed with a spatula. This method is inconvenient only in that the product consists of toxic solvents, that is, they can be used only in a room with good ventilation. By the way, a household substitute for such a tool can be, in extreme cases, a solvent.

The effectiveness of the thermal method is due to the property of the old paint layer to soften when heated. The paintwork is heated by a building hairdryer or a soldering iron, after which the paint begins to bubble and melt, and then is removed with a spatula.

Tip: in the absence of a building hair dryer, you can use a blowtorch, but this is much more dangerous and requires strict adherence to security measures.

Mechanical methods can be varied and rather unusual. You need to start with the ordinary peeling off a layer of paint with a spatula. Of course, this work is labor intensive and very dusty, in this regard, if the coating does not leave over the entire area, but only in certain places, it is better to clean just them. The rest the surface is primed.

If the layer adheres too firmly to the surface, use a metal brush to scratch the coating with it - this will increase adhesion before puttying. Another option is if there are no voids under the paintwork, make notches with a sharp object (say, an ax) (the main thing is that their depth reaches the surface under the paint).

This contributes to a better adhesion of the mortar to the surface when puttying is done on the paint. For the same purpose, paint stripping with coarse-grained emery is used manually or with grinding machine.

Tip: after this treatment, it is imperative to brush away the dust layer from the surface.

What to do if the paint could not be removed

If it is not possible to remove the paint, a special primer is used, which contains microscopic particles, it is they that improve the adhesion of the substrate to the putty. Quartz sand is often used as such particles, the liquid component of the product has the property of penetrating deeply into the paint coating layer, while simultaneously connecting with it. A similar primer designed to cover smooth surfaces is called Concrete Contact. Its main purpose is to provide a smooth surface with roughnesses that will facilitate the application of putty.

If there are cracks in the coating, they are “embroidered” with a spatula, that is, the exfoliated paint, as well as the plaster under it, is removed to a durable coating. In the process, large recesses can form, they need to be putty smoothened over the paint layer, and then after preliminary priming, begin to level the entire surface.

After applying the primer with a roller or brush, it is advisable to do plaster mesh installation, which will greatly facilitate the work. It is especially necessary if the future plaster layer on the walls exceeds 10 mm.

How to putty on paint

Further actions are identical to those that are produced when leveling and finishing a conventional plastered surface. However, there are specific features of this work.

• With a significant deviation of the wall from the level or the presence of serious defects, the surface is first leveled with a starting putty, which has a coarse-grained structure;
• Putty on the processed paint will hold on more firmly if it is applied in several layers, the thickness of which is up to 2 mm. Each subsequent layer can be applied after the previous one has completely dried;
• After the final drying of all layers, the surface is cleaned with a sandpaper or a special mesh so that it can remove the influx and traces of a spatula.

After this, the same principle is applied. finishing putty. After drying of its last layer, it is also subjected to grinding to a state of perfectly smooth surface. This operation is especially relevant if painting is to be done.

As for the technology of applying plaster, first a small part of the solution is applied by spraying so that a reliable base is formed. When this base is dry, proceed to the basic leveling procedure with a plaster rule or trowels.

At the final stage, a primer is applied to the walls. After that, you can color them or wallpapering.

Following all these recommendations, you will very quickly forget that a perfectly even layer of putty hides the peeling coating underneath.