How to choose and correctly use a putty

Recommendation points

• Composition of putties
• Dry and ready-made putties
• Application of putties in various conditions
• Base and finish layers
• What color to choose
• Price and manufacturers of putties

Not a single important repair is complete without the use of putties, with which you can make the surface of walls and ceilings even and smooth. The correct choice and competent use of this material in finishing works will be discussed in the following chapters..

Composition of putties

Putty or, which is the same thing, putty is a finely dispersed paste-like mixture used for the finishing leveling of ceilings and walls. After application to the prepared surface, it hardens and forms a strong and reliable base.

The main components of the putties are:

• a binder (powdery substance) with the help of which the material hardens within a short period of time;
• fillers (chalk, limestone, crushed marble, etc.);
• modifiers that improve the properties of the composition;
• water.

Depending on the type of binder, putties can be gypsum, cement and polymer. Organic glue is sometimes used as a bond.

The smaller the filler fractions, the thinner the putty layer can be. Formulations with coarse ingredients (up to 0.6 mm) are used to apply the first leveling layer. Mixtures with fractions up to 0.3 mm are used already for finishing. Smaller inclusions (up to 0.2 mm) have polymer putties, which form the smoothest and thinnest leveling layers. The higher the level of gypsum grind, the smaller the particles and the thinner the finish. To determine what the minimum thickness of the finishing layer is permissible for a particular material, it is necessary to find the numerical size of the fraction on the packaging of the finished composition and multiply it by three.

Modifiers make the putty pliable, flexible and easy to use. It is important that during the finishing process it is easily applied and smoothed, does not run off and does not form visible seams. To do this, you should know well the time during which the solution remains “efficient”, until the moment when it begins to thicken.

Before buying a putty, you should especially carefully read the recommendations and instructions on the product packaging..

On average, such performance remains (per bucket of solution) for gypsum mixtures – about 30-60 minutes, cement – up to two hours, and polymer (in a closed container) – up to several days. Also, you need to know the time of final hardening of the putty layer applied to the surface. All these parameters are primarily affected by modifying additives..

Each manufacturer has its own technology for preparing modifiers. That is why, before buying a putty, you should especially carefully read the recommendations and instructions on the product packaging. Disregard for these simple rules leads to disastrous labor results. For example, if cracks appear on the newly hardened layer of putty, you should not immediately judge the poor quality of the material. It is possible that the work was carried out:

• at an air temperature of more than 300C or less than 50C;
• with air humidity exceeding 80%;
• the application of the putty took place under the influence of wind, rain or direct sunlight.

In general, the most optimal conditions that meet the requirements of many instructions are an air temperature of about 200C, and a humidity of 60%. All other conditions require the adjustment of the technology of work in one direction or another.

Dry and ready-made putties

Manufacturing companies produce putties that are ready-to-use or simply in the form of dry mixes.

The powdered material is easy to transport and can be stored even in cold (but dry) warehouses. To prepare a solution, the product, in strictly defined proportions, is poured into a container with water. Then everything is stirred until a certain homogeneous mass. The higher the skill of the painter, the higher the quality of the putty. To obtain a homogeneous mixture without lumps in large volumes, use a drill mixer. A skilled craftsman knows that the rotational speed of the tool nozzle should not exceed 800 rpm. If this condition is violated, a large amount of air will enter the solution. The result is a loose mix.

In the putty layer, voids (shells) are formed from such a batch. In any case, after stirring, the mixture should be left alone for 5 to 15 minutes. During this time, the ligament will dissolve, the modifiers will “work” and air bubbles will come out. Then the whole mass is stirred again for five minutes. To avoid direct skin contact with the mixture, it is necessary to carry out the entire procedure in protective rubber gloves.

Ready-to-use mixtures are intended for those who want to get a thinner putty layer during finishing, and in this case there will be much less dust and dirt. To obtain such a filler, manufacturers use a particularly fine filler (fraction size from 0.002 mm to 0.1 mm). Kneading is done using special equipment. It is almost impossible to make such a solution with a simple mixer, since after the “manual” method, dry small places will remain in the mixture. And at the factory everything is done in accordance with the production technology, after which the products are packaged in sealed packages.

Ready-made putties are made on an aqueous vinyl or acrylic mixture, as well as on organic solvents. Unlike dry products, the finished mass cannot be transported and stored at negative temperatures. The only exceptions are putties with special additives..

Application of putties in various conditions

Before buying a putty, you should decide where and in what conditions it will be used: inside a building or on its facade, in a cold, humid or dry room.

For cold and damp conditions, moisture resistant cement putties are used. They withstand repeated freezing and thawing well, do not swell from moisture and damp air. And if you prepare the base correctly, then they are also suitable for dry rooms..

In general, compositions based on organic, polymer or gypsum bonds are intended for normal operating conditions. Gypsum fillers, for example, have natural beneficial properties. They know how to “breathe”, that is, they can absorb and give off excess moisture, thereby smoothing the level of humidity in the room. However, constant, pronounced temperature and humidity changes, such a product will not withstand for a long time – the finishing layer will sooner or later begin to crack.

On the packaging of each putty there is a technical description, which gives detailed instructions on where and how this material can be used. However, the most common mistake many finishers make is using the wrong type of product chosen for a specific location and environment. A typical example – ceilings, walls in damp or cold rooms, and sometimes facades, many are finished with polymer fillers. And moisture is contraindicated for such material. As a result, the layer swells, loses its strength – with all the ensuing consequences. Will decorative paint applied on top help in this case? The fact is that most paints are hygroscopic, that is, they do not create an absolute obstacle to moisture. Therefore, it will only be a delay in time for inevitable negative changes..

Another common mistake of repairmen is the application of cement putty to gypsum or cement-lime plaster. It would not have existed if these workers knew one construction axiom that the foundation in its strength should always exceed the level of strength of the material applied to it.

All putties (dry and ready-made) are usually used for leveling grooves, filling small cracks and final high-quality surface finishes. Most often, they work on a layer of plaster. Also, putties are applied on flat surfaces treated with special primers designed to increase the contact area (for smooth concrete) or reduce and evenly distribute absorbency (for brick walls). If the putty is applied to a brick wall without any primer, the layer will crack due to its uneven drying, since the brick and cement joints between the masonry absorb moisture differently. Therefore, to obtain a high-quality result, you should correctly select and combine building elements – base, plaster, primer and putty..

Base and finish layers

Putties are not cheap. It is ineffective to apply them in several layers or in one thick layer – expensive material is consumed, and drying requires a long working time. For preliminary smoothing of unevenness of various substrates, you can use plaster, which is cheaper in cost. And already directly on it, the base (1 – 3 mm) and finishing (up to 0.5 mm) putty layers are applied. Material compatibility will be best if they are all from the same manufacturer.

But other finishing technologies are also possible. Only one final layer of putty can be applied to high-quality, even plaster. In general, you can do without plaster when finishing smooth but porous cement bases. For this, the surface is first primed, and then a base putty layer is applied to it. After it dries, the surface is sanded, dust particles are removed and covered with a finishing layer of putty.

You can get by with one base layer if, after finishing, dense, embossed wallpaper will be glued to the surface.

For very thin and light wallpaper or for the subsequent painting of the surface, finely dispersed finishing putties are used.

How neatly the repairmen do not work, after finishing, sagging, trowel marks and other flaws remain on the surface. Therefore, sanding of the dried putty layer should be a must. To save time, you may not sand the entire surface, but only some individual areas. The best result is obtained when sanding layers of finished putty with a fine-grained filler (up to 0.015 mm). When carrying out a similar operation with layers of plaster from dry mixes with coarse-grained fillers, the product particles will fly out and scratch the surface..

What color to choose

The color of the putty is not so important when finishing the surface, which will then be painted or pasted over with thick wallpaper. High-quality paint and varnish material has good hiding power and any even contrasting color of the putty is completely painted over. The same can be said about ornamental and dense types of wallpaper – under them not only the color of the putty material is not visible, but also small surface flaws are invisible. But for thin and light wallpaper, and some other cases, you should use more expensive colored cement putties. With the help of these compositions, you can save on decorative materials..

For example, white putties, in which polymer glue is present as a bond, can be applied to ceilings and walls by spraying. The “fur coat” obtained in this way is usually not painted over. Such a surface, even for a long time, will not turn yellow.

Price and manufacturers of putties

Of course, a significant factor affecting the choice of filler material will be its cost. Traditional claims that ready-made compounds are more expensive than dry products, and gypsum putties are cheaper than cement putties are not always true..

There are different price segments – expensive and budget. It should be borne in mind that a more expensive putty may have a lower consumption than a material in the same package, but cheaper in cost. The real price can be calculated by the cost of an expensive and cheap composition per square meter of surface, provided that the thickness of the putty layer is the same.

A trusted and reliable manufacturer of quality products usually has a higher price..

On the domestic market of building materials there are putties for various purposes and price ranges from such companies as: Russian – GLIMS-Production, Ural Construction Mixes, Volma, Prospectors, Yunis; Polish – “Atlas”; German – “Henkel” and “Kreisel”; Swedish – “Beckers”; Finnish – “Tikkurila”; American – “United States Gypsum”.