I decided to write an article on the topic: how to make gypsum stronger, or rather, how to make a gypsum stone several times harder. In general, I don’t need a particularly strong stone, people buy it as it is and it doesn’t break and there were no complaints. Even thin-layer bricks with a thickness of about 6 mm are perfectly transported and laid. But during production, it remained on my polyurethane forms - this is all due to the insufficient strength of the products and because of this I decided to use an additive.

Experiment

I decided to do an experiment and took 3 tiles:

1. From gypsum Magma G6 B3;
2. Gypsum Magma G6 B3 + gypsum converter SVV-500;
3. From gypsum G16 (Samarsky).

Plaster Converter SVV-500

The G6 and G16 gypsum stone gained its strength, I cast them about a month ago, and I cast the stone with the addition of SVV-500 a day before recording the video. He has not yet gained his final strength, but I still decided to do an experiment, because. the effect is superb.
I added 4% converter to the solution. I got 2.4 kg of gypsum and 96 grams of SVV-500 per mold. I added the additive to dry gypsum, mixed it thoroughly, and only then dissolved this whole mixture in water. When pouring, the solution looked like liquid condensed milk, it took 2 times less water than usual. The time from filling to unforming increased by about 10 minutes. When pulling out the stone, I noticed that even the raw tile became much stronger and broke with effort. You can watch the experiment in the video below.

Conclusion

To be honest, I did not expect such an effect, I thought, well, the tile would become a little stronger, like from G16 gypsum no more. I'm afraid to imagine what will happen if you mix G-16 + SVV - there, in general, "concrete" should turn out.

I'll put the CBB tiles aside and shoot a new video in a month and add it to this page. I want to see if the stone becomes even stronger or not. Thank you all for watching, if you have questions, write them in the comments.

Second video

Reviews of other people (I am there too)

You can buy the additive SVV-500 on the official website of the company Emulsion angidrit.ru/products/gipsan

By the way, I tried another supplement, you can see the review.

Discussion: 2 comments

Gypsum is great natural material for the manufacture of various interesting things, but, unfortunately, products from it do not always turn out to be strong enough (even from high-quality gypsum). On the Internet you can find many ways to strengthen gypsum, but not all of them are clear and not all are suitable for home conditions.

The methods that we use ourselves and which really help to make gypsum stronger:

1. Adding PVA glue. In our opinion, this is the simplest and affordable way increase the strength of gypsum at home. Glue must be added to the water and stirred, then pour the gypsum. We usually use the following proportions: for 1 kg of gypsum - 0.5 liters of water and 50 grams of PVA glue. The solution becomes thicker due to the glue, but the products are noticeably stronger.

2. Addition of reinforcing fibers (polypropylene fiber). Fiber is usually used for reinforcement concrete structures, but it can also be used for gypsum. Polypropylene fibers significantly increase the resistance of gypsum to temperature changes and prevent cracks in the product. One kilogram of polypropylene fiber can be enough for 500-1000 kg of gypsum. It must be added to the water before mixing the solution, approximately 1-2 grams per kilogram of gypsum powder. Products with the addition of fiber do not crack so quickly and severely under the influence of frost and high temperatures. There is a small minus in the use of reinforcing fibers - in some places the fibers can be visible on the front side when the finished product is poured into the mold (not always and quite a bit, usually not critical) and are noticeably visible and can even stick out from the side of the filling and during molding. In Belarus, you can buy polypropylene fiber in small quantities with delivery to any locality(sellers are easy to find in search engines).

3. Finished goods can be strengthened coated with acrylic primer. If a craft even made of G-16 grade gypsum can be easily scratched with a fingernail, then after coating with a primer, it is much more difficult to do this without foreign objects.

The methods described above can be combined for maximum effect. There are also various plasticizers that change the properties of gypsum, including strength, but they are more suitable for large-scale production of gypsum products.

How to make strong gypsum or production technology and recipe decorative stone and 3D panels.

Good day everyone!

Time allowed and I got to the most intimate - how to make gypsum not just strong, but very strong.

I'll tell you right away! Forget about what is written on the Internet, about old-fashioned methods with lime, vitriol and shamanism with a tambourine. I'll tell you a little secret, most professional manufacturers of gypsum products do not work like that, they just joke on beginners, forcing them to slake lime and soak in vitriol))).

In reality, everything is much simpler many times over and the strength of gypsum can be very high.

During production, only a few additives are added to gypsum and a strong product is ready. What is this miracle supplement? You ask.

These are the so-called cement-polymer mixtures. Self-manufacturing such an additive is completely impractical, it is easier to buy it ready-made, since it is inexpensive, around 80 rubles / kg. and is added from 10-20% of the volume of any gypsum or alabaster.

Let's take a closer look at this supplement and who produces it.

The production of this additive is carried out by the Formako company (www.formako.ru), which, in addition to the mixture, produces various forms for plaster and concrete. Sold in bags of 10 kg. from 1 bag and anyone can buy.

How does Formaco supplement work?

5% additives- the gypsum is soft, but no longer dusty, less sticky to the mold. It pours unevenly.

10% additives- the plaster becomes stronger. It pours unevenly.

15% additives- a product made of gypsum is much stronger, the mixture begins to pour much softer, the formation of bubbles decreases.

20% additives- the product cannot be scratched with a fingernail, it pours very evenly and softly.

25% additives, the maximum is already an excessive fortress for gypsum, but someone might want to.

How this additive affects the strength of gypsum in more detail you can see in the table

The recipe for the preparation of strong gypsum for absolutely any product. From decorative stone to statues.

Please note that the data for water is slightly averaged, for different plasters or alabasters it may differ slightly

As you can see, it is enough to add this mixture and your gypsum product will become heavy-duty.

Which gypsum is suitable for the production of 3D panels or decorative stone

what formaco does is a cement additive based on kaolin and additives, in principle the recipe is known, the whole focus is on additives and percentages of these additives

I completely agree with you, here on the forum they already left a review about it

Categories

Fresh comments

• Ivan on How does gypsum differ from alabaster and which is better?
• gypsum master on Polyurethane mold for 3D panel - why is it good?
• back to Polyurethane mold for 3D panel - why is it good?
• Anonymous on Composition gypsum mixture for the production of 3D panels
• Alex on What is the difference between gypsum and alabaster and which is better?

Copyright 2017 Gypsum lover's blog. All rights reserved.

How to make gypsum stronger and increase the strength of gypsum?

Gypsum binder is one of the most ancient building materials. Building plaster has features that make it stand out. Such as, fast hardening, lightness and pleasant color. It has good heat and sound insulation properties. And most importantly, gypsum is a cheap material.

But there is one significant drawback, which "nullifies" all its wonderful qualities. Low strength!

Mankind has been trying to solve this problem for several centuries. Today, there are many ways to increase the strength of gypsum. But all of them are ineffective, because. growth is very small. Here are just a few of them:

• reduction of mixing water by introducing plasticizer additives;
• introduction of lime or various salts into the composition;
• administering PVA glue, liquid glass and other binders.

Exists good way increasing the strength of the gypsum binder by mixing it with cement and pozzolanic additives (GCPV). But this method is "dangerous", because. can lead to the complete destruction of such concrete. The thing is that the combination of gypsum and cement is unacceptable, because of the possible formation of a “cement bacillus” (etringite) in such a system, which destroys the formed structure. And even the neutralization of the "bacillus" with the help of pozzolanic additives cannot guarantee one hundred percent "safety".

The question, “how to make gypsum stronger”, remained unresolved until today, until a small company from Chelyabinsk was puzzled by it.

High-strength gypsum is a material that can replace wood or plastic in many cases. Its advantages are the low cost and availability of all components, ease of use, processing and preparation, the ability to adjust the cooking recipe (and hence the properties) to suit your goals. Areas of application - production of classic gypsum products, production of cabinets various devices and fixtures, cases, handles, assemblies, mechanisms, etc.

By building PVA glue, I meant anything, but not clerical in tubes, do I use PVA +, or PVA super?

From a comment:

Mikhail Mikhin

1. Release agent for gypsum castings is done as follows:

A paraffin household candle is planed and dissolved in kerosene in a water bath (a container with kerosene is in a pot of water and all this is on the stove). You check the density by dipping a stick into the solution and under water at room temperature - you need the density of oil or sour cream.

Such a lubricant, after drying, leaves no traces, but only the thinnest paraffin layer.

2. Deep impregnation of gypsum with epoxy and other materials is done as follows:

the part is heated in the oven, the air comes out of it and is immediately coated on all sides the right material. The part cools down and air under atmospheric pressure drives the impregnation into the gypsum to the maximum depth.

2. The threads should be soaked in water before immersion in gypsum, so that air would also come out of them.?

From comment: :

Dmitry YaGod

There are different PVA, on the water and not water based(carpentry) .... by the way, if you add PVA to cement mixture strength is crazy

From a comment:

For the form you can also use silicone sealant. A sealant is applied to the model so that a rigid shirt is made of plaster or boards (plywood or something else) so that it does not deform. And so that the gypsum does not stick to anything, you can also generously grease it with soap, Vaseline or even cover it with varnish. This, of course, if the products are not piece. Even for a fortress (and probably economy), sand was added to gypsum earlier. We somehow interfered with cement (a handful of cement for half a bucket of dry gypsum).

From a comment:

Darius Verbitsky

Interesting technology, thanks for the idea, I also added color for the paint, the result is a bomb, and dried the tiles in the microwave with wax paper for the oven?

From a comment:

Was the mixture cement-sand?

Answer: +Bernard Friedman yes?

From a comment:

Ivanovich Ivanov

When preparing the mixture, I always first dissolved the PVA in water until a homogeneous suspension, and only then added either gypsum or this suspension to the prepared cement mortar- there is more time to work with the finished solution and the solution is more homogeneous.?

I worked in a printing house for several years and found out about glue: do not take stationery PVA, there is still a hodgepodge, it is diluted (and very strongly) with kmts glue + chalk (or something else) is added, this is done to reduce the cost. Just take building pva, and if it seems too thick to you, dilute it with water, does it affect its adhesive properties in any way?

Answer: I agree by pva glue (construction) I meant anything but clerical in tubes, do I use pva +, or super pva?

From a comment:

It is better to immediately dissolve PVA in water and not one fourth, but one tenth is enough, I think it is better to take a primer not for deep penetration, but fortifying ... the same ST-17 or Bolars. This one is cheaper...

Instead of fittings, you can try fiberglass. Just make the mixture thinner?

As reinforcement, you can add fiber (fiberglass) sold in hardware stores to add to the floor screed mortar.?

From a comment:

Pavel Fedorov

Can! if you use reinforcement. let's say you have tiles a centimeter thick and two meters in size. firstly, you need to take care of the form, and the separating composition, as mentioned earlier. I'll add my 5 cents - experiment with glycerin. it does not leave stains and retains adhesion in the molded surface.

So, the reinforcement can be in the form of a frame - glass mesh or fiberglass, and here I remind you that gypsum is an alkali, and we need alkali-resistant reinforcement. wire and thread also go. yes, they can be cut, so we move on to without frame reinforcement - cellulose comes to the rescue - paper brought to a state of porridge, fiber, which will make the surface hairy. there are also recipes for the introduction of minerals and various polymer additives - as a result, you will get plaster. pay attention to the knauf nr-start mixture. it just has a base thickness of 10 mm and a favorable cost.

And, of course, external reinforcement! for this purpose, we go to a building materials store and choose the so-called dry plaster sheet, and in the common people drywall. he is already 9 mm and already handsome! however, if this is not our method, then I suggest you take thick paper _ in this case, the solution should be extremely dry - (take plaster, you won’t have time to mix it with gypsum), because it will distribute paper from moisture, cardboard in the flesh to karst or binding, do not stretching fabric like matting, tulle with an intricate pattern or glass-paper with original weaving and in the absence of a die, we roll out the decor of our dreams with a roller, a smooth kelp or a rule for this purpose is also suitable. you can take a stretchy fabric and artistically emboss it with stamping or a palette knife, and finally, building glass canvas or interlining or wallpaper - these are also our methods. all these reinforcement methods are fully compatible in one project.

Next, we should be interested in the balance of properties of gypsum. a denser and more resistant to deformation-mixture is achieved with the supply of vibration during pouring, however, it does not have elasticity for solidification. any shear or breaking load will break it. and here I want to remind you that gypsum itself is not hard at all, this property is introduced with zinc sulfate at the production stage. you can push yourself and soak in a solution of copper or iron sulphate found in a gardening store. the authentic color will be lost in this case.

The property of elasticity appears in gypsum after creating a porous structure in it, but this does not mean that it will become like rubber! it will simply be less critical for shear and tear, but its deformation strength will also decrease. the cellular structure of the pores gives it these properties and it can eventually be pushed through with a finger. this is achieved by the introduction of an air-entraining additive, such as soap. since the porous liquid loses its flowability, we add a plasticizer - soap, and an anti-separation additive in the form of soap to hold the suspension of crystallizing mineral conglomerates.

industry (here, of course, "Soviet industry" suggests itself - but no, Chinese ...) produces a wide range of additives for gypsum mortars that make it hydrophobic, weather-resistant, refractory, antifungal and even reasonable!

splash any primer into the mixture to increase the working time with it, a pva solution is also suitable and always rinse the tool every 30-40 minutes of work - the setting time of gypsum dry mixes. add white or ordinary Cement to increase strength if texture and color sand is not important - it will also increase reactive properties.

Let's define the concept: gypsum (aka alabaster) is a substance of natural origin obtained as a result of heat treatment gypsum stone.

According to the degree of grinding of gypsum stone, the following fractions are divided:

• fine grinding;
• medium grinding;
• coarse grind.

By setting time:

• fast setting (2-15 min.);
• medium setting (6-30 min.);
• smoothly setting (20-30 min).

It should be remembered that gypsum is a perishable product, after 3 months of lying it loses its properties by 25-50%.

Solution preparation

Water is poured into the dishes and, stirring constantly to avoid lumps, gypsum is added. When preparing the solution, foam is formed, which must be removed, as it makes the future gypsum rather fragile. The ratio of water to dry matter in ready solution may be different.

1. Liquid gypsum mortar- 0.7 l of water to 1 kg of gypsum.
2. Moderate density solution - 1 liter of water to 1.5 kg of gypsum.
3. Thick gypsum mortar - 1 liter of water to 2 kg of gypsum.

Why increase setting time? Why not use a slow setting mortar? Slowing down the setting of plaster is necessary for working with a large volume of material, for example, in an art workshop, etc. If, after preparation, the gypsum mortar begins to harden, then the addition of water or simple stirring will cause the mortar to be ineffective, it will no longer set and will not harden. For this, various moderators are used. Do not forget that gypsum during hardening warms up and slightly expands.

Ways to slow down the setting of gypsum

1. Using carpentry or wallpaper glue CMC (other wallpaper glue not applicable in this situation). A 25% adhesive solution is added to the water and the gypsum is closed.
2. The second way to prepare an adhesive solution: dissolve 1 dry part of animal glue in 5 parts of water and leave for 15 hours, you can for a day. Then add 1 part of the lime dough and boil well over low heat, stirring occasionally, for 5 hours. In order for the solution to foam less, it is necessary to put a layer of gravel or pebbles 2 cm thick on the bottom of the dish. The resulting mass is added to the water immediately before work and the gypsum is closed with it. The quality is 2 times higher than the usual adhesive solution.
3. The next way is to use a 5-6% sugar solution. But sugar slightly reduces the strength of gypsum products.
4. Usage citric acid also slows down the setting of the plaster. A solution of 0.05% citric acid slows down the process by 30 minutes. A solution of 0.1% citric acid slows down setting by 1 hour. It is not recommended to use a large concentration of citric acid, since the strength of the gypsum product sharply decreases.
5. Quicklime or slaked lime is another of the retarders. In addition, lime is a good plasticizer, and this is very important for working with stucco. Better to use slaked lime in a ratio of 1:6 (we take 1 part of lime and 6 parts of gypsum).

You can use ready-made plasticizers that slow down the setting time. Remember that reagents will affect the quality of the plaster product in different ways.

Convenience and increased comfort in the bathroom is determined not only by new or recently changed plumbing, but also by decorative image gizmos that can bring a touch of piquancy and sophistication to an ordinary interior. There are a wide variety of bath mats on the market. And all of them are united by one thing - the ability to decorate a home, making it more comfortable for existence. Manufacturers offer...

Cottage village "Prozorovo" of the elite class has collected all the advantages and pluses country life with close access to metropolitan amenities and the business center of the capital. The new building is located 12 km from the Moscow Ring Road in the direction of one of the most prestigious areas of the Moscow region. You can get here along three modern and equipped highways - Novorizhskoye, Ilyinsky ...

"Vnesh-Komplekt" - repair of refrigeration compressors in Ukraine The refrigeration compressor is the main component of any installation designed to reduce the temperature environment in a closed space or freezing of various products and materials. Such equipment is used in almost all enterprises and in a variety of institutions - therefore, the effectiveness of their work largely depends on the serviceability ...

Gypsum. Working with plaster
Gypsum or gypsum binder is obtained as a result heat treatment natural gypsum stone and subsequent grinding. Depending on the grinding, gypsum is divided into groups: I - coarse grinding, II - medium and III - fine. According to the setting time, gypsum is divided into: A - quick-setting (2-15 minutes); B - normally setting (6-30 min); B - slow-setting (20 minutes or more). The tensile strength of gypsum is determined by 12 compression grades. Gypsum grades are as follows: G-2, G-3, G-4, G-5, G-6, G-7, G-10, G-13, G-16, G-19, G-22, G- 25. In the manufacture of stucco, gypsum grade G-7 and higher is used. The peculiarity of gypsum is that when dried, the strength of gypsum products increases 1.5 - 2 times 2 hours after mixing.
Gypsum is the only construction work a binder that expands and heats up during hardening while being warped, particularly in thick and long products. In the manufacture of stucco, the expansion of gypsum is a positive feature, because. at the same time, it penetrates into the smallest reliefs of the form (when casting parts). To reduce warpage, gypsum is prepared with lime water (slaked or quicklime is used for its preparation).
Gypsum is not recommended long time. The maximum storage period is three months. It has been established that after 3 months the gypsum loses its strength by 25-50%.

Gypsum mortar
A gypsum solution is prepared as follows: first, pour into a container required amount water, and then pour gypsum and mix quickly. Gypsum. the solution is prepared in various densities. To fill the molds, a liquid solution is used (0.7 kg of gypsum is taken per 1 liter of water), a medium or thick solution is used for pulling (1.5 - 2 kg of gypsum is taken per 1 liter of water). It is better to mix a large volume with an electric mixer. It is better to mix a small amount with a spatula or an ordinary tablespoon, or, if the solution is liquid, with a paint brush. Then plaster. the solution will quickly turn out homogeneous without lumps. The brush should be rinsed immediately with water. It is better to use a container made of polyethylene (for small volumes it is very convenient to use half a rubber ball). After the gypsum has set, it is easy to clean them by slightly deforming the container. At the same time, the remnants of the seized gypsum crumble and depart on their own.
Gypsum should be prepared very quickly and used immediately. If the gypsum dough (gypsum mortar) that begins to harden is again mixed with water or simply stirred for a long time, the gypsum rejuvenates and ceases to harden or set. It is no longer possible to use such a solution.
To slow down the setting of gypsum, retarders are used. A good retarder is a weak adhesive solution, which also gives increased strength to gypsum products. For the preparation of glue water, you can use CMC wallpaper glue (it is still found in stores, not to be confused with the usual wallpaper glue) or wood glue. You can use a 5-6% sugar solution, but remember that sugar slightly reduces the strength of gypsum products. Lime water also slows down the setting of gypsum, in addition increases its strength and prevents warping of products. There is another simple way to prepare gypsum so that the solution does not set quickly and there is more time to work with it. Gypsum should be poured into a container with water, but do not mix, but let it soak in water. This solution can be used a little longer.
If you want to speed up the process of setting gypsum, then you can add to the water table salt 1-4 g per 1 liter of water, or mix gypsum in hot water.

ps I'm not sure that all the materials listed here will be harmless to ants.