How to prepare a gypsum mortar for construction work. Is it possible and how to put a cast at home on an arm or leg

Unique natural material, which is gypsum, is indispensable in construction, medicine and architecture. Consider the preparation of building gypsum mortar.

Gypsum and its properties

is obtained after grinding gypsum stone burned in rotary kilns, which is mined in quarries with gypsum-containing rock.

There are many varieties of gypsum: building, polymer, acrylic, polyurethane, sculptural, architectural and refractory. In construction, gypsum of the same name is mainly used.

One of the main advantages of gypsum is its fast setting and hardening, which significantly speeds up and facilitates the execution. finishing works with its use.

During the curing process gypsum mortar slightly increases in volume, densely filling all the recesses and pores of the surfaces treated with it.

One more useful property gypsum is that the walls plastered with it absorb from the air excess moisture, giving it away when the air becomes too dry.

In addition, gypsum is a highly environmentally friendly building material, it does not emit harmful substances and does not pollute the environment.

Preparation of gypsum mortar

To prepare the solution, pour into a bowl right amount water, and then pour gypsum powder into it in a thin stream, constantly stirring the mixture.

A small amount of poured gypsum, passing through a layer of water, will quickly be wetted and after 1 minute a gypsum dough is formed in the dish, ready for use. The solution obtained with this method will be homogeneous, with the same density.

If, however, gypsum powder is first poured into the container, and then water is poured into it, it is unlikely that it will be possible to avoid the formation of lumps.

For manual mixing of the solution, it is better to use a spatula made of wood, plastic, rubber or of stainless steel. In case of preparation large volumes gypsum mortar, it makes sense to arm yourself with a special nozzle.

In order to avoid the loss of its properties by gypsum, never stir the solution for more than 1 minute - immediately put it into operation. The fact is that it is after such a short interval of time that the process of setting the gypsum begins.

Neglecting this advice and stirring the solution more long time with the addition of water to the hardening gypsum dough, the solution will begin to rejuvenate. The strength of the surface finished with its use will be very, very low.

How to stretch the process of gypsum hardening in time? Use gypsum mortar setting retarders.

Adding to the water during the preparation of a solution of bone or skin glue, a keratin retarder from the waste of processing horns and hooves, calcium caseinate allows you to increase the hardening time of the gypsum up to several hours.

Home craftsmen often use CMC wallpaper glue, PVA glue, sugar, milk, washing powder, soap solution, shampoo or dishwashing liquid.

For the opposite effect - to accelerate the setting of the gypsum mortar, dissolve potassium alum (5 g per 1 liter of water) or table salt (1 g per 1 liter of water) in water before kneading it.

Good luck to you! May you succeed!

What is gypsum used for? Artists have long used this product to make masks, sculptures, and other voluminous projects. You can also do crafts at home, such as bubble painting and making pavement chalk using plaster. Thus, it is a multifunctional product that can be used in a variety of ways.

Gypsum can be purchased at different places. It can be ordered online, from art catalogs, and arts and crafts stores. You can buy plaster bandages, but you will need to submerge them in water in order to use them to make the crafts you intended to use the cast for, whether it be making a piñata or a mask. In addition, you can buy gypsum in powder form, which will need to be mixed with warm water to use to create a variety of artistic crafts.

You can make a variety of plaster - depending on how inventive what you have planned to do and what kind of craft you want to make. Most experts will agree that it's easier to go out and buy a package or Plastic container with powdered gypsum to be mixed with water to create your own piece. However, you can also make your own own plaster for simple projects.

Making plaster at home is a great experience for preschoolers, from students primary school. In addition, if you are doing crafts at home and are on a budget, PVA glue or flour are great option, replacing the purchase of powdered gypsum in arts and crafts stores.

In order to make plaster at home, you probably have everything necessary materials at home and you only need time to make a product for your craft. There are two recipes for making gypsum at home for your choice.

First, you can knead the composition, which is diluted with PVA glue and warm water. At the base of this recipe you use 2 parts PVA glue and 1 part warm water. Pour glue and water into a plastic bowl. Add water while stirring the mixture until it becomes a slightly thickened substance. The final product should be liquid and similar to the consistency of PVA glue.

Secondly, you can knead the paste to use it, just like plaster. Take two or three cups of white flour and one or two cups of warm water. Mix flour and water in plastic cup, mix until the lumps disappear, its consistency should be homogeneous, namely easy to mix.

1. masks;
2. papier mache;
3. piñata;
4. bubble drawing;
5. suspension structure;
6. chalk for drawing on the sidewalk.

Caution: You may need additional drying time adhesive mixture. And make sure you get the newspaper or gauze strips completely wet before applying them to the mold you will be using for your project.

Your final product will be completely man-made, from your own plaster of paris. By devoting enough time and attention to preparing a plaster of paris of the required consistency, you will successfully complete the job and be satisfied with your craft or handmade project.

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Alder (common) Family: Betulaceae Commercial names: black alder (UK); gray alder (Europe); Japanese alder. Other names: aune (France); eis (Netherlands); Erle (Germany); hannoki (Japan). Spreading: Northern Russia, North Africa and West Asia, throughout Scandinavia and Japan, and throughout the United Kingdom of Great Britain. Description of Alder wood The color of the wood is dull, light reddish brown with darker lines…

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Building gypsum is versatile material, from which it can be made plaster mixture, and a solution for casting decorative elements. You only need to keep proportions and know how to breed building or finishing composition. And in this article we will talk about the methods of preparing gypsum mixtures and the technology of working with this material.

Varieties of building gypsum - what do the letters A, B and C mean?

Granular gypsum (alabaster) is used in construction business, decoration and even jewelry art since time immemorial. However, today this material is supplied to construction sites and workshops not in its pure form, but in the form of a loose mixture prepared by roasting the sedimentary mineral. With the help of this technology, modern industry produces three types of material labeled as "building gypsum", namely:

• Composition of type "A" hardening in two minutes. Castings obtained from such a mixture completely harden in a quarter of an hour.
• Composition of type "B" that sets in six minutes. It freezes within half an hour.
• Beginning to harden after 20 minutes type "B" compound. The timing of the final solidification of such a solution depends on the proportion of the dry part and water in the proportion according to which the gypsum is diluted, and on the level of humidity in the room.

Due to the too rapid hardening of type "A" compounds and the long setting of type "B" mixtures, they are not used on construction sites. In the construction industry, gypsum type "B" is used, which retains plasticity for half an hour and begins to set in 6-10 minutes. Moreover, not just B-type gets to the construction site, but special formulations, capable of withstanding pressure from 20 to 70 kilograms per square centimeter of area. How much a particular variety can withstand can be found by the alphanumeric code in its labeling. For example, the composition with the designation G-7 can withstand a pressure of 7 MPa or 70 kg / cm 2.

However, the final properties of the solution depend on the method of its preparation. Therefore, further down the text we will tell you the basic proportions and rules according to which you can dilute gypsum, getting the basis for decorative elements(stucco, etc.) or plaster compositions.

Two ways to prepare gypsum for castings

Even a primary school student can prepare a solution at home. To do this, do the following:

• take a bucket of 5-10 liters;
• pour a liter of water into a bucket;
• pour 0.7 liters of B-type dry composition into water;
• Stir the mixture thoroughly to a creamy consistency.

The composition diluted according to these rules can be poured into molds, but the resulting product will not be very durable. Therefore, most decorators follow a different recipe:

• take a liter of water;
• pour 0.1 liters of loose slaked lime into the water;
• add 0.6 liters of gypsum "B" or "C" type.

After curing, such a composition will not crumble so much, and if it is covered protective composition, having previously primed, then such a casting can be used not only in the interior, but also in the exterior (outside the house). If you cannot remember how much water, lime and gypsum are needed in liters, use the proportion 10:1:6.

Moreover, the quality of the solution depends not only on the components, but also on the very process of preparation, or rather, on how to add the dry part to the water and how to mix this mass in order to dilute the gypsum correctly. According to most builders, at the very beginning it is necessary to add water to the bucket. Then a dry base is poured into the water, but not immediately, but in a thin stream. The mass obtained at this time is mixed, but not with a mixer, but with an ordinary stick. The mixer can only be turned on after the last grains have fallen into the water.

How to prepare plaster with chalk and wood glue

Compositions for plastering surfaces are sold in the form of ready-made mixtures, the basis of which is gypsum. In addition, the recipe contains lime, mineral fillers and dry adhesives. Store mixes are divided into starting and finishing varieties. The former are used for drafting and leveling walls, the latter for final finishing. But if you didn’t have enough ready-made mixture to complete the plastering of the surface, then you can prepare the plaster with your own hands. To do this, you need to take a kilogram of B-type composition, three kilograms of chalk and 200 grams of wood glue. Dry components are thoroughly mixed, and it is better to add glue to water.

Alternative recipes involve using lime paste (1:1) instead of chalk, or sawdust(1:4). In the latter case, one part of dry tile adhesive is added to the composition.

Liquids for any home-made composition need no more than 300 ml per kilogram of dry mix. Stir the plaster better mixer inserted into the chuck of a screwdriver (mains, not cordless). And, as always, water is first poured into the container, and then plaster is poured into it. In a word, a recipe for making homemade plaster mortar assumes the same implementation conditions as the technology of mixing store dry mix.

Making colored plaster - a 4-step job

The standard color of gypsum casting or plaster is yellowish grey. If the mixture is made from pure material, the color can be white-gray. This combination does not suit all designers. However, this shortcoming is easily corrected using recipes for the preparation of colored solutions. To do this, we need a classic set of components: water, pigment for water-based paints, lime and gypsum. The process of preparing a colored solution is as follows:

• Take a bucket with a tight lid with a volume of about 3 liters. An empty water-based paint container is best suited for these purposes.
• Pour a liter of water into the bucket and dissolve the paint pigment in it. In this case, the density and color saturation will have to be maintained "by eye", controlling the consistency of the pigment visually.
• Mix a 100-gram glass of dry slaked lime into the water. And carefully beat this mass to a creamy consistency, getting a lime dough. If the color of the dough differs from the desired one, add pigment and mix the composition again.
• Mix in half ready solution six 100-gram glasses of gypsum, pouring it into the dough in a thin stream and mixing thoroughly. At the end, turn on the construction mixer and achieve a uniform solution.

The composition obtained in this way can be used for pouring into molds. If you are planning to get colored plaster, mass fraction lime in the solution should not differ from the volume of gypsum.

How to slow down the solidification of the solution - vinegar, soap and drying oil will come in handy

Working with gypsum requires a very high qualification from the plasterer or decorator. Indeed, even a relatively plastic B-type compound hardens in 6 minutes, and the most durable mixtures based on A-type compounds lose their plasticity in literally 100-150 seconds. Although such a solution takes from 30 minutes to an hour to completely solidify. Of course, too rapid solidification does not suit either professional builders nor homegrown lovers.

Professionals are forced to mix the solution in microscopic portions, breaking away from their main work every 5-10 minutes. Amateurs have an even harder time - they cannot use up even a microscopic portion of the solution in 4-5 minutes, which forces them to throw away the remnants of the frozen material. Therefore, before diluting gypsum, professionals and amateurs add special additives to the water that slow down the setting and hardening of the solution. And if such additives are not at hand, then home-made compositions prepared according to the following recipes are used:

• Pour 4 tablespoons of vinegar essence into a liter of water. After that, the composition will harden for 40 minutes.
• 100 shavings are added to a liter of water laundry soap. On this basis, the solution will solidify within 20 minutes.
• 100 grams of drying oil are mixed into a liter of water. Such a solution will retain plasticity for 15-20 minutes.

In addition, the base can be kneaded not on water, but on wallpaper glue (paste). In this case, the solution can be used for at least half an hour. And during this time, even an inexperienced finisher will cope with a portion of the solution.

The best solution when needed gypsum is that this procedure is done by a doctor. Unless, of course, you are going to simulate a broken limb. However, there are times when this knowledge and skill can be very useful.

With the use of bedding-free dressings, gypsum is applied directly on the skin of the hands. Gypsum hardens to the required hardness in twenty minutes, but complete hardening occurs somewhat later. One of the reasons for the need for the presence of a doctor is the need to check the correct connection using x-rays. You may have to remove the plaster and redo everything.

For the same reason, it is desirable that the physician participate and during plaster removal. You need to take a second shot and be sure that everything has grown together correctly. In addition, it would be absolutely useful to receive the doctor's recommendations on methods for treating the fracture site for successful healing.

How to make your own plaster

To apply gypsum, gypsum powder, bandages are needed different widths with a total length of up to three meters, warm water.

To begin with, make sure that the powder is suitable for use, for which mix a little gypsum and water in equal proportions and after about six minutes, make sure that the mass has hardened. If so, then the first stage was successfully completed. Even when buying, check that the gypsum is finely ground and white.

Water heated to 40°C should be prepared.

If you have not mastered enough plaster technique and if you want to slow down the process of gypsum hardening, add 3% solution of glycerin.

Immerse the bandages in the basin until they are completely covered with water. The bandage should be completely saturated after a while.

How to apply plaster

The bandage should be slightly squeezed and applied, slightly overlapping the turns. Wrinkles that appear must be smoothed out immediately. Twenty minutes later, when the primary hardening of the gypsum occurs, X-ray control is very important, but if it happens in field conditions and in a short time it is not possible to carry out this operation, it should not be forgotten. As soon as possible, at the first opportunity, this control must be carried out.

If offsets are found, remove plaster and do everything right. However, if you have already reached the X-ray machine, then the doctor should be somewhere nearby.

Plaster fixation

If the misfortune, after which a cast is needed, happened somewhere outside the city, and by all indications it is a fracture, be sure to fix the ankle joint with a tight bandage in the form of a figure eight, when the bandage passes from the foot to the lower leg, leaving it open. Further, during transportation, the patient should be seated in the back seat of the car so that the injured leg is stretched (horizontal). It is good to apply some kind of cold to the fracture site and hurry with delivery to the hospital.

If you are a supporter of such outdoor activities, which can lead to fractures, it is very appropriate to attend first aid courses. medical care and bring all necessary materials with you. This will save you from unnecessary unnecessary and unprofessional hassle and you high level help yourself or a friend. This operation is simple, accessible, but, as in any business, there are, of course, subtleties.