Is it possible to pour plaster in the gypsum form. How to breed the building gypsum. How to dilute plaster: not only the proportions are important

The use of gypsum in construction and everyday life has such deep roots that it can be easily attributed to the oldest building materials. But it is not easier to work with it - you need to know not only how to dilute the plaster, and what proportions to use, but also many other subtleties associated with this material!

Building gypsum - quickly grasps, holds for a long time!

IN repair work Gypsum is used very widely: both as part of other solutions as a binder component and "solo". Gypsum you meet in plastering mixesA modern modeling and sculpture is made of gypsum, as well as. Building gypsum is a white powder with a grayish tinge, which is enhanced by adding water. It is obtained by this material from a gypsum stone, which is born in the furnaces at a temperature of about 150 ° C and is crushed to obtain a homogeneous powder.

Depending on the grinding, you can meet gypsum of fine grinding, middle and coarse - only thin grinding for construction and repair goals! Powder that is used in construction is divided into three temporary groups:

the group "A" denotes the highest setting speed - from 2 to 15 minutes;
the group "B" is the materials that grab no faster than 6 minutes and no later than half an hour;
the group "B" - to this group include gypsum, which freezes no earlier than 20 minutes.

On the brand gypsum shall be divided by its degree of compression. For example, material with marking M-6. It is easy to guess what denotes the letter, but the figure tells us about how the tensile strength of this material in this case is 6 MPa. As a reminder school program, 1 MPa (megapascal) is a pressure that is 10 kg per square centimeter.

For construction work, material from M-2 to M-7 is used, which belong to the B. Group By the way, the alabaster is a generalized name that covers all construction stamps, and in professional terminology from this term has long been refused, preferring to specify information, using marking. The noteworthy feature of the building gypsum lies in its ability to expand when hardeningwhereas other materials give shrinkage. Expanding slightly - the volume increases by 1%, which fully fits the needs of builders and repairmen.

The even enough plaster is quite high strength at low density 1200-1500 kg / m 3. Speaking on understandable languageThis material will be 2 times lighter than the same cement! In addition, it has minor heat-conducting characteristics. It all applies to the pros, but there are also cons! The most important is too fast frosted speed. Therefore, in his work it is impossible to store for a long time in such a state, or rather, with all the desire you will not work, because the gypsum will freeze in the tank.

Does not save and constant mixing, moreover, it is impossible to do this, because the plaster with each minute will lose its characteristics.

That is why the gypsum is kneaded by "factory", so the masters are called small portions of mixtures. On the use of the "factory" at the master only a few minutes, during which it should not only apply it to the surface, but also to dissolve. If this is not done, and the material will freeze at least partially, it is no longer suitable for serious works! This is also called the "dead" plaster, after drying it will crack and causing you by spoiling you all the work.

Since the gypsum powder has low hygroscopicity, its use is rational only in rooms with low humidity. If you are afraid for the condition of the coating, it is better additionally after its complete drying to cover it with moisture-proof composition. Since the structure of the material is quite porous, first the surface will need to be prepared - apply the appropriate primer.

Storage conditions - What is the shelf life?

Stopping in plaster - an extremely bad idea! Firstly, this material cannot be called scarce, secondly, no matter how you try to provide him with the proper storage conditions, the treacherous moisture will still find a crack, through which it will penetrate into a bag or a different container with plaster and merges with it in strong Soyuz. Even in perfectly dry room, he will lose his qualities over time. The same applies to derivatives - if you are going, try after buying materials, do not postpone work in a long box.

But even if you purchased bags with plaster with the point, to use it in the coming days, attention to the storage conditions of the powder should be paid special. The most important and obvious condition is dry! It is best to put bags with a material of 30-50 cm above the ground level, for example, on pallets or bags with another material. If the holes were formed during transportation in bags, then it is better to close them with slices of polyethylene.

If you are in doubt for some reason as a powder, we have simple tests before using it. All you need to do is stir a small amount of material and apply it to metal surface. Try to move exactly from the moment of stirring before the start of solidification - these indicators must comply with the stated on the packaging of the brand.

How to breed plaster construction - simple calculations

Whatever the brand you have chosen for work, it is necessary to breed the building gypsum on the contrary - not water is added to the powder, but powder into the water! Before proceeding to work, select a suitable container, plastic or metallic solution to create a solution, most importantly, then from its inland walls It was convenient to lift the remnants of the material.

In the container, pour water - one piece into two parts of the powder. Then slowly, trying to distribute the powder across the water area, stir the mixture until the water is completely absorbed into the powder. At least a bit of the resulting solution should stand out - if the material is slightly heated and thickened, it's time to use it! It is very important to remember - in the already beginning to seize the solution cannot be added none of the components separately! Having done this, you will spoil the entire mixture, having obtained a solution with extremely low knitting characteristics.

How to breed gypsum - proportions of different compositions

The lack of a mixture of plaster powder and water is a very high speed of frost. It is worthwhile to go to the master, or make too big kneading, and write gone! That is why ways were invented to slow down the speed of solidification of this material without loss of its remaining characteristics. The method is first - preparation of plasterboard mastics. For this composition, 15 g of glue is divorced on the bucket of water. Instead of joinery glue, you can also use another, more complex solution from lime and metering glue.

First you will need to prepare a lime-adhesive mixture. To do this, take 1 kg of metering glue, soak it in five liters of water and leave for 15 hours - during this time it will wet and acquire the necessary consistency. 2 kg of limestone test is added to this mass, it is well stirred and boiled 5 hours on slow heat. As a result, you will receive a finished concentrate that can be completely or in parts in water (for the entire mass - 20 liters of water) and mix with plaster.

On one liter lime adhesive solution, stirred with water, you need to add 8 kg of plaster. Calculate how many water can be needed on this mass - as you already know, it is better to add powder into water, and not vice versa, so it is recommended glue composition Stir with liquid immediately per gypsum. Such mastic begins to capture no earlier than 20 minutes after it is prepared, which gives enough time for "maneuvers". By the way, adding an ordinary cook salt will allow you to get the opposite effect, namely - to speed up hardening!

Smooth walls are a guarantee of high-quality repairs. And one of the simple and reliable ways to align and decorate the walls is their plastering. In this article we will analyze all questions related to gypsum plaster: What is needed for which its features and specifications, pros and cons, and applications. And also clearly show how to work with this material.

Application of plaster plaster

Plastering mixes based on plaster apply to finishing first of all walls and ceilings residential roomsAs well as other rooms with normal humidity.

It can be put on such bases as:

brickwork and clay walls;
over concrete walls and (need treatment with concrete contact);
on old gypsum plaster provided its good strength;
on cellular foam concrete, aerated concrete and ceramzit concretes;

Since the plaster is able to absorb moisture, it is used only for interior decoration dry premises during surface preparation or.
Gypsum plaster can be produced in the form:

starting mixtures or finished solutions;
fine-grained finish;
decorative compositions.

Currency prices:

Plaster plaster

What is part of

The main component of this type of plaster is the building gypsum - calcium sulfate hydrate, obtained by firing a gypsum stone and chopped to the state of the powder. The composition can also add:

fillers that reduce weight and increasing heat insulating properties light plaster: perlite, vermiculitis, foam glass or polystyrene foam;
plasticizers and seders of setting;
additives Increasing White Surfaces - Salt various metals (zinc or titanium bleel) or lime;
components that increase their strength;
additives, regulating the time for setting the solution and its hardening.

Gypsum plaster refers to environmentally friendly materials and is absolutely not dangerous to health. Moreover, due to its hygroscopicity, it is able to "breathe", that is, absorb the surplus of moisture and, on the contrary, to give it, thus adjusting the microclimate in the room.

A separate type of gypsum plaster is a plaster emergency. It is used to align brick and concrete surfaces. Gypsum compounds in some cases can also be used for external finishing works.

Specifications

The quality of mixtures on plaster binder is regulated . According to this document, the main indicators of dry material include:

humidity: moisture content is allowed not more than 0.30% of the total mass;
the limit size of the granules (grains);
volumetric weight: 800-1100 kg / m3 (in a loose-sufficiency state) and 1250-1450 kg / m3 (in a compacted form).

Properties of cooked solutions:

water consumption when kneading - 0.6-0.65 l / kg
mobility: the ability to spread under the influence of its own weight; According to GOST 31376, the diameter of the vague sample of the prepared solution (~ 600 g) should not exceed 165 mm (± 5);
setting time - at least 90 min for machine application mixtures and 45 minutes for shocking manually;
time of complete drying - in 5-7 days; This indicator depends on the additives in the mixture and differs from different manufacturers; To find out how much the plaster dries, you can in the instructions on the package;
the ability to retain moisture, not allowing it to drain: at least 90%;
consumption at a layer of 10 mm - 8.5-10 kg / m2 (manual application) and 7.5-9 kg / m2 (machine).

Properties of plaster plaster in the solidary form:

compression strength - 2.5 MPa;
the clutch force with the surface is 0.3 MPa;
density - 950 kg / m3;
parry permeability - 0.11-0.14 mg / PCPA;
thermal conductivity - 0.25-0.3 W / m * C;
shrinkage - does not give a shrinkage

Although the vapor permeability (the ability to pass water pairs) of plastered surfaces is not regulated by GOST, it is also an important technical characteristic that determines the scope of application of plaster.

When purchasing gypsum mixtures, close attention should be paid for their expiration date. Due to the ability to easily absorb moisture longer than 6 months from the date of release, they are not stored. After this period, their properties change, they begin to compete, and the qualitative alignment of the walls is becoming problematic. It is necessary to pay attention to the tightness of the packaging that protects against excess moisture is not to acquire plaster in torn bags should not be purchased.

Pros and cons

The main disadvantages of this material include Low moisture resistance and strength - surface plastered with plaster, can be easily scratched or tired. The cost is slightly higher than cement-sand mixture, approximately 15-20%, but this is a non-essential minus.

But still the benefits of gypsum are much more:

high plasticity: working with plaster mortar is easier than with others; The laboriousness of the process is significantly reduced, and this is a significant plus;
no shrinkage: in cement mixtures, it makes a couple of millimeters per square meter;
surfaces placed by plaster are obtained smoother, without pores and graininess;
good adhesion: the gypsum solution sticks to the surface is much better than sand-cement; Therefore, the reinforcing mesh for strengthening the surface can not be used; It is required only in new buildings due to a possible shrinkage of the building;
good heat and sound insulation properties: The wall covered with a layer of plaster keeps heat and protects from noise better than concrete surfaces;
it is allowed to impose a thicker layer (up to 50 mm) without reinforcing mesh;
light weight: Gypsum covered walls give a smaller load on the foundation;
efficiency: when comparing the cost, many pay attention only to the weight of the pack; However, it is necessary to take into account specific gravity The mixture - after all, the consumption of gypsum per 1 m2 is 9-10 kg, while cement for plastering the same area will already need 16-18 kg.

Opinion expert

Alexander Guryanov

Plasters and Master of Decorative Finish

Many refer to the benefits of plaster and more high speed Grappling than in cement-sandy solution. However, it is difficult to call this significant dignity. Indeed, the surface treated with gypsum plaster solidifies 1-1.5 hours faster than covered with cement composition.

I don't have to slow down when working with it, it is not necessary to block the novice to stick the solution will be problematic. Do not dive too much a mixture if you work yourself. Better, if one person is prepared, and the second plasters.

How to breed a dry mixture

Consider the process of preparation and proportion of a gypsum solution. The dry mixture of the bag is shrinking into the prepared container, already filled with water. According to instructions on 1 kg, 600-700 ml of fluid is required, that is, there will be about 20 liters of water on a 30-kilogram bag of plaster.

A small amount of solution can be simply mixed with a cylma or trowel. If large volumes do with your own hands, it is better to use a perforator with a mixing nozzle or a construction mixer.

The solution must stand 3-5 minutes (component response time). Then he again thoroughly mixed up to the complete disappearance of all lumps. The solution should be viscous and plastic, but in no case flush from the tool.

Plasticizers Gypsum

However, at home, it is possible to make a mixture based on plaster with your own hands, for example, a fairly plastic. But the reaction between the plaster and water occurs quite quickly, so the gypsum plaster quickly hards.

To make a convenient solution to work in it be sure to add one of the plasticizers:

diluted glue plow, about 1% of the total;
lime, used as a plasticizer and to increase the time of frozen;
wine lemon acid Also slow down the grasp. FROM pecial fluids, for example, Plast Retard PE are able to extend the time of setting to several hours, prevent the appearance of cracks and improve the wear resistance of the gypsum.

Application in wet premises and on the street

As we have already mentioned, the gypsum plaster can absorb moisture, so its use in wet premises and especially for facade finish Not desirable.

If it is necessary to make the surface of gypsum moisture resistant (for example, when prepared for cladding tiles in the bathroom), it is covered with primer deep penetration on acrylic basis. Under the tile perfect suited primer Conconduct.

The polymer waterproofing mastic, for example, "hydroelast plophonite" has good moisture protection properties. It is applied over a thoroughly dried layer of plaster with a brush or roller in several layers. Each of them needs to be applied after the height is previous. The tile sticker is allowed only after the day after applying. The same mastic is recommended to fill out the places of pipe output and corners of various designs.

How to plaster with a gypsum solution (video)

You can work with plaster plaster using a plastering station or manually. Machine application is a separate topic for a conversation, and consider it in another article. And here we will analyze the nuances of manual application.

the thickness of each layer can be 30-50 mm; If necessary, a new layer is allowed to apply only after drying the previous one;
consumption of a dry mix in the absence of large irregularities with a layer thickness of 1 cm - an average of 9-10 kg / m2;
gypsum solution is allowed to be applied not only on brick, concrete surfaces and aerated concrete, but also the previous layer of cement or plaster plaster;
the surface alignment is carried out with the help of beacon profiles or gypsum beacons - a small amount of a mixture, which is pointing point or along the line and is aligned in terms of level; After their drying, a solution is thrown between them, and then the entire plaster mass is spread construction Rule; The thickness of the layer will be equal to the height of beacons;
for dedusting, protection against shuffling of small particles and strengthening the surface after plastering, the surface must be projected;
to obtain a flat plane before painting or gluing thin wallpapers, the walls are additionally putty;

The video below shows all stages of finishing: how to properly knead, apply and rub.

Grouting and shiny

Grout is the removal of manually small irregularities, seams, transitions between layers. Usually rubbed after drying plaster. For this take a metal or plastic grater. The tool is wetted with water or primer intended for applying after plaster, and process the surface with circular or vertical and horizontal movements, periodically cleaning the grater from the solution. Special attention is paid to the corners.

On the video above (time 5:35) the process of glossing the surface is shown - creating an ideal plane without finishing putty. Glossy and rub - Very similar methods, the same tools and techniques are used. But the difference is that it is for just climbing and still wet plaster. This saves time, and there is no need to apply putty.

Finishing aligned walls

After applying the layer of plaster, it is necessary to determine how further finishes will occur:

As you can see gypsum mixes V. Extremely in demand finishing and repair work And used everywhere.

We hope that this article was useful to you, and you have found the information you are interested in. Please leave your questions and comments in the comments below.

Or for making small sculptures. The technology of preparing the solution is quite simple. The main thing is to know what kind of ratio components are mixed. It is worth noting that the gypsum is the main material for making crafts.

What is plaster

Before answering the question, how to properly breed plaster for crafts, it is worth understanding what kind of material it is. First of all, it is very plastic. Gypsum can be applied to almost any kind of surfaces. The material is easily processed and quickly solidified. Gypsum is used in many industries: as a fertilizer, as one of the components of paper and cellulose production, as component of enamels and paints. Use the material also for the manufacture of internal decorative elements. Often, the gypsum is used as a binder component in construction.

Disadvantages of material

So how to breed plaster for crafts - simple process, It is worth considering certain disadvantages of the material. This will greatly facilitate work with him. First of all, the gypsum has low hygroscopicity and strength. Therefore, use decor elements made from this material, indoors with high humidity Not recommended. Such situations require additional processing. For reliability, ready-made crafts should be coated with a layer of coatings protecting from moisture.

Before starting work, the hygroscopicity of gypsum products should be taken into account. They absorb any coating well. Therefore, it is recommended to apply a layer of primer to the surface of the product. Only then you can use a coating that protects against moisture.

How to breed plaster for crafts: proportions

There are several basic methods for making a gypsum solution for making crafts. The easiest method is water breeding with water. In this case, it is important to observe all the proportions. At 7 parts of the gypsum requires at least 10 parts of water. It is worth noting that it costs to prepare a solution with extreme caution so that there are no lumps. It is recommended to add plaster to water, and not vice versa. This method also eliminates dust formation.

Such a solution is easy to use. From it you can make products almost any form. However, it is worth considering that the crafts are not very strong. They will easily break and crumble. So how to breed the plaster for crafts?

The second method

So, how to breed plaster for crafts. This method Preparation of the solution is a bit more complicated than the previous one. However, the mixture allows you to produce stronger and reliable products that retain your appearance over the years.

To prepare the solution: 6 parts of the gypsum, 10 parts of the water, 1 part of harated lime. The components are gently mixed until the formation of a homogeneous mass.

Manufacture of colored gypsum

How to breed plaster for crafts different colors? This will require:

Gypsum.
Gouache.
Ordinary water.
Bank with lid.
Dishes for the preparation of the solution.
Spoon, shovel or wand.

Entering process

So, how to breed plaster for crafts from a multicolored solution? In fact, the process is quite simple. To begin with, it is worth pouring a gouache in the bank and the amount of water required for the preparation of solution. To paint dissolve completely, it is recommended to close the can with a lid and shake a little.

The painted water should be pouring into the dishes, where the preparation of the solution will occur. Here, by observing all the proportions, you must gradually add plaster. Put the powder into the liquid is a thin flowing, constantly stirring the components. This will make it possible to achieve a homogeneous consistency of the solution. The mixture should resemble a thick sour cream. Stir the solution in the cooking process is carefully so that there are no lumps and air bubbles. Otherwise in ready product Middles are formed.

How much craft drows out

Now you know how to breed plaster for crafts. How much does the product dry? Grapples and gradually pouring the gypsum solution 4 minutes after its manufacture. Therefore, working with ready Material It should be quickly and neat. Full solidification of the gypsum occurs after half an hour. To set the solution to occur more slowly, it is worth adding a slightly water-soluble adhesive on an animal basis.

What can be replaced by plaster

On the this moment Many sets for creativity are for sale. How to breed the plaster for LORI crafts, and the material from other sets to create figurines, as a rule, is always indicated in the instructions. It should be studied before starting work, as the solution quickly dries. It should be noted that in some sets for creativity analogs of gypsum are applied. The most common one is alabaster.

This powder has a grayish shade and has a finely dispersed structure. The material is obtained as a result of thermal processing of two-wheel gypsum. Due to this, the finished solution received completely different characteristics. It is worth noting that externally alabaster and plaster are very similar.

Than alabaster differs from gypsum

Among the main differences between these substances it is worth allocating:

How much drowned crafts from alabaster

Determine the timing time of the material by studying the technical characteristics of the mixture. In general, the decay of the alabaster solution is observed 6 minutes after the dilution of the substance. Partial frost occurs after 30 minutes. It is worth noting that the faster and dried solution is able to withstand the load of 5 MPa. Fully alabaster dries over 1-2 days. Despite the fact that products from this material are stronger, it is not recommended to use a solution for classes with children, since it is not entirely safe for health. Gypsum in this case is preferable.

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"Gypsum (from Greek Gypsos - chalk, lime) mineral, aqueous sulfur salt calcium.

It is found primarily in the form of solid grainy (alabaster) and fibrous (selenit) masses, as well as various crystal groups (gypsum flowers and other).

Gypsum is widely used to obtain binding materials, for the manufacture of hypsobetone, as an amicing (selenite) and a facing stone; in the production of paints, enamel, glaze; In medicine and optics.

Gypsum serves as a source material in solutions intended for the fulfillment of hollow spheres from the sculptural original ... "

Big Soviet Encyclopedia, Third Edition, Volume 6, Page 549.

Artists and craftsmen have long appreciated the properties of the gypsum, which is simply indispensable for the manufacture of forms for casting sculptures, copies of models, coins, etc. from various casting materials (wax, bronze, plaster itself), plastics ( organic glass), epoxy resin.

Lubricant

When working with plaster forms, an important role is played by lubricant, separating the shape of the casting.

For example, when casting a relatively simple gypsum objects in the gypsum forms, the lubricant consisting of a solution of steaarin or paraffin in kerosene is most common, but for a fine-thin transfer of the relief of plaster castings, soap foam is used (for the same purpose, the shape is washed with sweat, calcined by soda or mortar. copper sipop).

How the lubricant showed itself an emulsion consisting of soap, vegetable oil and water taken in a 2: 1 ratio (parts by weight). When coating the sphere of this emulsion, an insoluble calcium oleate is formed (calcium soap). With mass castings on plaster forms, a solution of epoxy resin in acetone is caused.

Grappling

The molding gypsum is a quick-conchive binder, and according to GOST, the launching began to occur no earlier than 4 minutes from the date of the chipping test, and the plaster hardens no earlier than after 6 minutes, but no later than in 30 minutes.

Special substances are used to regulate the timing setting of gypsum - inhibitor and catalysts - from which the first slows down the reaction, and the second - accelerate the grasp.

5-10% carbon black, as well as some solutions: 2-3% - borants are used for the indion as inhibitor solutions; 5-6% - sugar; 5% - ethyl alcohol.

3-4% solutions of catalysts, sodium sulfate, sulfate of potassium, etc. are used as secluding catalyst solutions.

Hardness

To increase the hardness of the product from the gypsum to the latter in front of the shutter, the lime of the membrane is added, sifted through a thin sieve. After that, the gypsum is embossed, the solution is thoroughly mixed and poured into the form. After grapping plaster castings dried in a warm place.

It gives the fortress of plaster impregnation of its products for a day with a solution of 5% boron acid ammonium heated to 30 degrees. Note that the boring ammonium must be prepared correctly. And they do it. First in warm solution boric acid In the water added when stirring in small portions ammonia Until the lactium paper starts painted in blue colour (The liquid has pH \u003d 6-7). After that, the fluids are given to stand.

Increases the strength of the casting the glauble salt, the solution of which is treated with the finished cast.

The hardness of the gypsum will increase significantly if it is created by water containing up to 50% of flintic acid, and the finished cast is then heated to 60-80 degrees.

Another way to impart gypsum gypsum is embeded in an almost saturated drill solution. The finished casting is first impregnated with barium chloride, and then coated with a hot soap solution and washed with water.

One of best ways The production of high-end gypsum is a 2-hour impregnation of a gypsum casting with zinc or iron vigor.

It is permissible to produce plaster castings by alumokalia alum, which also increases the hardness of the gypsum. Having rolled around the day the product in a saturated solution of alum, it is given to dry, after which the casting is heated to a temperature of 550 degrees. Gypsum treated with alum solidifies slowly, but hardened, reminds the strength of ceramics.

Note that with an increase in the amount of water added to the lave plaster, the lastness of the latter decreases, since the excess of water evaporates, as a result of which pores are formed in the gypsum.

Cleaning contaminated gypsum castings

Gypsum castings are contaminated with time. The reason for this is dust and a rag, which this dust with castings are brushed. Here are some tips, how to clean the contaminated gypsum surface and give it a fresh look.

Tip # 1. The surface of the gypsum sculpture is treated with a vacuum cleaner, then impregnated with low-fat milk. The latter is absorbed by the surface of the gypsum, creating a thin film on it, representing casein. Then they apply a layer of mastic consisting of a white wax dissolved in the turpidar and a small amount of oil zinc. Mastica is applied to a bristly brush gradually, a thin layer, as if rubbing the mastic into the surface of the gypsum. After drying the first layer of mastic after 4-5 days, the second is applied. After such treatment with mastic on the surface of the plaster, a white matte film is formed.

In the future, the plaster sculpture covered with mastic can be washed with water.

Tip # 2. A simple composition that removes pollution with a gypsum sculpture is diluted in water starch (hubber), which is applied to the gypsum surface and give dry. The film formed as a result of this sculpture scrape the wooden scraper together with the mud sticking to the starch.

TIP # 3. To impart a plaster sculpture of a snow-white type, it is coated two or three times with zinc white, divorced in adhesive water (weak solution of joinery glue).

Tip No. 4. A method for removing pollution with plaster and marble sculptures is very effective. synthetic materials based on polyethylene wax.

For the preparation of 5-15% paste polyethylene wax (it turns out to be so!) Dissolve in xylene at a temperature of 40-50 degrees. The prepared paste is applied with a soft durable brush so that there are no hairs from the brush on the casting. After formation on the surface polyethylene film last with pollution remove

Instructions for the preparation of solutions for casting decorative stone

Gypsum - the only thing in construction work A binding substance that expands and heats up when hardening, simultaneously undergoing warping, in particular in thick and long products. In the manufacture of stucco, the expansion of the gypsum is a positive property, because At the same time, he penetrates the smallest reliefs of the form (when casting parts). To reduce the charges, the gypsum is prepared on lime water (lime water is obtained by mixing 1 kg of lime test from 6 to 8 kg of water).

Gypsum Solution

Prepare a solution: first in the container poured required amount Waters and then pour the gypsum and mix quickly. For filling of forms, a liquid solution is used (1 liter of water takes 1.5 kg of plaster), an average or thick solution is used for pulling (1 liter of water takes 1.5-2 kg of plaster). Large volume is better mixed with a mixer. A small amount is better mixed with a shovel or a conventional tablespoon if the solution is liquid - painting tassel. Then the solution will be quickly homogeneous without lumps. Tassel should be immediately rinsed in the water. Capacity is better to use made of polyethylene or plastic. After grapping the gypsum it is easy to clean, slightly deforming the container. At the same time, the remnants of the grab gypsum crumble and depart themselves.

Gypsum should be prepared very quickly and immediately use. If it starts to harden the gypsum dough (gypsum solution), mix again with water or simply mix it for a long time, the gypsum is rejuvenated and stops hardening or grabbing. It is impossible to use this solution.

To slow down the timing of gypsum sedels apply. A good retarder is a weak adhesive solution, which, moreover, gives the increased strength of plaster products. For the preparation of adhesive water, you can use the luggage glue CMC (it is still found in stores, not to be confused with the usual looping glue) or carpentry glue. For the preparation of the adhesive solution, it is necessary to do the following: 1 The weight of the dry animal glue is soaked in 5 weight parts of water for 15-16 hours or more. After the glue is completely dissolved, 1 weight of the limestone test is added to it and the mixture is boiled in a water bath 5-6 hours, after periodically stirring it. The resulting concentrate before use is bred by water, and plaster is bred on the resulting adhesive water. By its effectiveness, such water is 2-3 times higher than water prepared on a conventional adhesive solution.

To reduce the boobing of gypsum and slowing it, it is also used by a boor, which takes 0.5% by weight from the total amount of water on which the gypsum is indulge. After drying, immerse the gypsum product into a solution of copper sulfate (tight blue color), after re-drying (it will be long!) Strength will increase significantly.

To facilitate the mass of gypsum products, they are prepared from gypsum mixed with sawdust, which slow down the grasp of gypsum. Products can be made with the addition of coarse sand or rubble (fractions 3-5 mm) in the gypsum of coarse sand.

Drying gypsum products are necessary in a warm room with a temperature of not lower than 16 ° C, but in no case on a draft, which contributes to the warping of cast products.

Lime water also slows down the grasp of plaster, in addition, it increases its strength and prevents product stamp. In the production of gypsum products, high-quality harated lime is necessarily applied.

Lime in the production of plaster artificial decorative stone, and other all kinds of gypsum products are applied necessarily and is one of the most important components in the production of gypsum products.

In the production of gypsum solutions for the manufacture of gypsum products, it is possible to use lime dough, as well as a long-haired membrane, but the best effect gives the quality of the gypsum solution with a limestone dough. The quality of the products, the fortress, drying time and many other qualitative indicators depends on the quality of the gaured lime in the composition of the gypsum finished products From gypsum. Lime significantly affects the quality of gypsum products, even if the stone falls into a wet or raw room, it does not absorb moisture and has significant strength.

In the manufacture of artificial stone from the gypsum using painting, it is necessary to take into account that if there are lime in the composition, then the rate of pigments and dyes should be slightly increased, because the lime that is located in the composition of the gypsum is able to partially discolour pigments, dyes and applied caloring pastes for Coloring of gypsum products. The increase is necessary by 15-20%, while discoloration occurs only in the first days after the manufacture of artificial stone and painting, and in the future dried fake diamond No longer loses color.

There is another simple way to make gypsum so that the solution is not quickly grabbed, and there remains more time to work with it. In the water capacity, you need to pour the plaster, but do not mix, but give it to be impregnated with water. Such a solution can be used a little longer. If you need to speed up the process of setting the gypsum, then you can add a table salt 1-4 g per 1 liter of water, and / or breeding plaster on hot water.

The setting of the gypsum is significantly accelerated when it is stuck with a reduced amount of water compared to what is required for the test of normal lugs, and vice versa. But it requires an additional vibration of flooded forms, for the distribution of a thick solution throughout the form and increased degassing.

The increase in the temperature of the gypsum test to 40-46 ° C contributes to the acceleration of its setting, and above this limit, on the contrary, slowing down.

To change the properties of stone (strength, frost-resistant, etc.), various additives are used, the most popular of them is a plasticizer. Plasticizer is an additive that allows you to increase the fluidity and plasticity of the mixture with a decrease in the watercraft ratio. This increases the final strength and density of the hardened solution. The plasticizer is sold in two types - liquid and powder. And both for ease of use need to be diluted in water.

The weight of the supplements used, including dyes and plasticizers, are determined in the percentage ratio from the solution. The average weight is 1-2% of the total weight of the solution, unless otherwise indicated in the instructions for the substance.

Cement-lime solution

Preparing the same as the usual, but instead of water uses liquid diluted lime. The cement-lime solution is sufficiently durable and plastic. For the manufacture of durable lime solutions M400 - M500 cement brands use the following cement / lime / sand / sand / crushed stone fractions 3-5:

cement White M400 - 1 / 0.1 / 2.5 / 2.5

cement gray M500 - 1 / 0.3 / 2.5 / 2.5