What determines the drying rate
The drying speed of any material is directly dependent on temperature and humidity.
The peculiarity of obtaining mixtures for leveling surfaces is the need for dilution of dry ingredients with water. During the set of strength, water evaporates, and the treated surface acquires the necessary characteristics. High temperature and dry air accelerate this process, while low temperature and high humidity slow down.
In construction, there are standards at which the process of curing occurs in the optimal mode:
- the temperature should be positive, from 5 to 25oFROM;
- humidity from 50 to 75%;
- coating thickness;
- features of the base material.
We’ll talk about the last two points in more detail.
At low temperatures, the process of curing is practically stopped and special additives must be used to restore it. Too high a temperature leads to premature and uneven drying of the solution, which reduces the strength of the coating.
A layer with a thickness of 3-4 mm will dry longer than a layer with a thickness of 2-3 mm, and therefore it is customary to impose several thin layers, which ultimately form a strong and smooth surface.
On a porous surface, the process of gaining putty strength is faster than on a denser basis, but the rapid absorption of moisture can also lead to uneven solidification. In this case, it is important to properly treat the surface with a primer before starting work.
How much putty for walls dries
The full set of strength process depends on the conditions (temperature and humidity), as well as on the type of binder.
Polymer
Acrylic or latex-based leveling compounds are used for all types of surfaces. These binding elements do not lose their properties at high humidity, and therefore they are used both for interior decoration and for leveling the outer surfaces. But the high cost of the material narrows the scope of application to extremely responsible rooms where it is necessary to obtain a perfectly smooth surface.
Due to its exceptional ductility, the material is easily applied with a thin layer of up to 1 mm, which, accordingly, affects the timing of the final polymerization.
Depending on the thickness of the coating, the drying period of the surface with the possibility of further processing for painting is from 3 to 4 hours. In this case, the unused mass can maintain its properties in a tightly closed container for up to 10-14 days.
Gypsum plaster
Compositions with gypsum as the main binder are used only for internal work, as whole layers of putty can fall off with increasing humidity from the leveled surface.
This disadvantage is compensated by the drying speed of gypsum putty, excellent adhesion and its relative cheapness. Also, due to the lack of shrinkage of the material during drying, no cracks form on the surface.
When working with this material, you can manage to apply several layers per shift. Depending on the thickness of the coating, the drying time may vary. from 3 to 6 hours.
The only inconvenience is the quick drying of the finished material in the storage tank. Because of this feature, you have to cook the mixture often in small portions.
Cement
The drying time of cement-based grout is - not less than 24 hours. The indicator is valid for normal temperature and humidity conditions and with a coating thickness of not more than 4 mm.
It should be remembered that this type of putty is used to smooth the surface of facades, and therefore, in conditions of low outside temperature and high humidity (for example, in winter), the period for a full set of strength for further processing can stretch to 2-3 days.
The long drying time is compensated by the possibility of leveling the surface for painting in rooms with difficult operating conditions. In addition, it is the cheapest type among the putties under consideration.
How much wood putty dries
Regardless of the type of material for leveling wood, its drying time is approximately one - 4 hours. During this period of time there is a sufficient set of strength required for further processing with sandpaper or a grinding machine with subsequent painting.
The instructions for finished putties on wood, as a rule, indicate a period of complete drying of 1 day, but you can work with the treated surface earlier.
For metal
Putty drying speed for metal is the highest among the materials under consideration.
The main determining factor here is the volume of thickener used in the preparation of the mixture. The final drying period, as in the case of wood putties, can be 1 day, but for processing with sandpaper or a sanding machine, the surface will be ready in 0.5 - 2 hours.
Polyester materials reach readiness for processing in 15 minutes, and recovery white putties, such as Colomix, up to 2 hours.
How to determine if putty is dry
When determining the drying time of the material, take into account the manufacturer's instructions, but, in addition to it, you can also focus on the external signs of complete drying of the surface.
In practice, two signs of the readiness of the leveled surface for further processing are taken into account:
- It has no cracks, chips, lumps. Perfectly smooth wall without defects will provide good adhesion when applying paint.
- It has no color shades. If the wall or ceiling is the same color, it means that the drying process went evenly. If darker spots are found on the surface, the putty is not completely dry.
When you can carry out further work
Any subsequent operations should be carried out no earlier than the complete drying of the putty layer.
Painting
To determine the start date for painting, you should know how much the finishing putty dries. At normal room temperature and humidity, a topcoat up to 3 mm thick will stand up not less than 24 hours. Deviation in temperature and humidity increases up to 48 hours. It is this time that is usually required to properly paint the walls in the case of plaster or drywall (read also about priming GKL before putty here).
The same period will be required to start laying tiles in the toilet or bathroom.
Before starting work on painting walls or ceilings, after the putty layer has completely dried, it is recommended to treat the surface with a primer and begin work after the final drying of the soil.
The second layer of putty
The application of a second putty layer requires that the hydration be completed in the starting layer. The first layer will surely shrink, so applying the next layer to it is impossible without loss of appearance (cracks, chips).
Sometimes manufacturers recommend that the first coat be primed before the next coat is applied. In this case, you need to wait until the primer is completely dry (about 4 hours at normal humidity).
Wallpapering
Wallpapering is possible only after a full set of strength of the putty layer. Depending on the temperature and humidity conditions in the room, the drying period may vary 12 to 48 hours. So how long after putty can wallpaper be glued? Given the above, this is usually a period of 2 days.