Collapsible silicone mold for DIY casting. What and how to make molds from silicone sealant at home, its properties, where it is used What can be made from silicone

The article describes personal non-professional experience!

Silicone molds are used both in production and in everyday life. They are used to make gypsum products, such as decorative stone and souvenirs, in the production of soap, candles, jewelry, and in cooking for creating dishes and baked goods. For some applications, molds are produced from special types of silicone, for example, heat-resistant, for food and others.

In addition to silicone, polyurethane molds are also often used. We haven't worked with polyurethane, so we'll skip this topic.

There are many different silicone molds on sale, but it’s not always possible to find what you need. If you really want to, you can make a silicone mold yourself at home.

There are several ways to make molds with your own hands:

The most accessible way is using silicone sealant. Not the best option, but in some cases it can be useful. The only advantage that can be noted is the availability of sealant. The main disadvantage is that molds made from sealant quickly and easily lose their shape (stretch). In addition, silicone sealant in its pure form is inconvenient to apply to the product because of its stickiness, it takes a long time to dry, it needs to be applied in thin layers and before applying a new layer you need to wait for the previous one to dry completely (about 24 hours). Making the mold takes several days. To prevent silicone sealant from sticking to your hands and to make it easier to apply it to the desired relief, the sealant can be mixed with potato starch. The resulting mixture will be a bit like a thick dough and will be easier and faster to make into a mold. For silicone molds made from sealant, as well as for thin molds made from molding silicone, you need to make a rigid frame, for example from plaster, so that the mold does not deform when pouring.
Acrylic sealant is not suitable for making molds!
Use of silicone compound for making molds. It is a set of liquid silicone and a catalyst (hardener). The principle of operation is simple - 2 components are mixed in certain proportions and the resulting mixture is poured into the object from which the mold needs to be removed.

To fill the product, you need to make formwork around it. It can be made from anything: plasticine, plastic, wood and even CD boxes, the main thing is that it does not leak. Easy to seal with a glue gun.

The product itself does not need to be treated with anything (if it is not made of silicone) - silicone practically does not stick to anything and the mold is easily removed.

If the molded object has reverse angles or you need to make a 3D mold, you may (depending on the brand of silicone) need to make a composite mold from several parts. To do this, you must use a release agent.

The silicone must be poured in such a way that the molds can be smoothly joined together; for this, there must be holes in the first part and protrusions in the second. For this we used glue sticks from a hot-melt glue gun: the rods were cut in half and secured at the bottom of the formwork around the object being poured, before pouring the next layer, we remove them and cover the entire surface of the resulting part of the mold with a release agent so that the second layer does not stick to the first.

The photo shows a form made from Pentelast 710 after 45-50 plaster pours.

There are many varieties of silicone compounds, we only had the opportunity to work with 2 of them: Pentelast 710M and Pentelast 718. Both of these compounds are made in Russia and are available in 1 kg packages, and they are also among the cheapest.

Pentelast 710 M differs from 718 in its greater fluidity and longer reaction time with the catalyst (remains fluid longer). When cured, 718 is a little harder, no other differences were noticed.

Mix silicone with hardener strictly according to the instructions, quickly but carefully, so that
minimum air bubbles. If you add less hardener than necessary or mix it poorly, the silicone will remain in a “thick sour cream” state; if you add more, you may not have time to fill the mold.

After 24 hours, the resulting form can be used. These silicones are not the best in terms of strength, so for objects with reverse angles it is better to make composite molds. Unlike some ready-made commercial molds, which are initially cut to remove the resulting products
and do not tear when you stretch them, forms made from the above-described compounds will easily tear at the cut site. They stretch well without damage and you don’t have to worry about the shape breaking if you do everything carefully. We use these molds to cast souvenirs and figurines, and they can also be used to make soap.

Molds made from these silicones cannot be used for culinary purposes and polymer clay cannot be baked in them in the oven. There are special silicones for these purposes. They are also not very suitable for making decorative stone; for this it is better to use either molds made of more durable silicone or polyurethane.

Old and unnecessary molds can be used by adding them when making new ones; to do this, unnecessary molds need to be cut into small pieces.

To make composite silicone molds, it is imperative to use release agents.

By the way, the release agent has a shelf life of 6 months (indicated on the label), but it performed its functions quite well after more than 2 years
from the date of production. One bottle lasts a long time; you need to apply it in a thin layer.

Although we here describe methods for making molds at home, it is still undesirable to do this at home, because the catalyst is toxic and stinks very strongly, and the sealant also does not have the most pleasant smell. All work must be carried out in a well-ventilated area. As a last resort, you can use the balcony (like us :)).

Silicone is a soft and pliable material that is used to make molds. There is nothing difficult about making something like silicone at home from improvised materials.

How to make silicone at home - method 1

White Spirit;
pipette, spoon, plastic glass;
acrylic paint;
liquid glycerin;
silicone sealant.

All components are mixed in the following proportions: for 30 grams of sealant, take 150 grams of white spirit, 1 drop of paint and 3 drops of glycerin.

Place the sealant in a plastic cup.
Add the specified amount of paint and glycerin. If you don’t have a pipette at hand, you can use a straw.
Add white spirit.
Stir the solution until it is will not become homogeneous (paints will not should be visible).
Ready. You now have about 5 hours to use this silicone before it hardens.

How to make silicone at home - method 2

To make silicone you will need the following components:

ethanol;
liquid glass.

Sequence of actions when preparing silicone:

You need to prepare a suitable container in advance and create working conditions. The container can be any. Pour ethyl alcohol and liquid glass into it in equal proportions. Mix the ingredients with any tool (wooden stick or spoon). When the solution begins to thicken, it can be brought to the desired state simply by rubbing it with your hand. A white dense mass forms in the container, which after some time will become similar to plasticine.
The required shape needs to be sculpted only when the mass begins to harden. There will be no problems with this, since the substance will be plastic and soft, similar to rubber. Once you have the desired shape, set it aside until it hardens completely. The silicone will harden and the mold will become less susceptible to deformation.

How to make silicone at home - method 3

Add 3 tablespoons of silicone sealant and the same amount of potato starch to a plastic cup. The resulting solution must be stirred for 7-10 minutes. When the silicone begins to easily come off your hands and knead well, you can begin making the mold, which is very simple.

How to make silicone at home - method 4

Buy several packets of gelatin and the same number of vials of glycerin. The quantity depends on the size of the mold. Everything is mixed “by eye”, approximately 50/50. Try not to violate the proportions: if there is little glycerin, the mixture will be liquid, and if there is too much, it will stick like glue. 55/50 is the best option.

All this needs to be heated in a water bath, but an ordinary candle will do. Your main task is to prevent the gelatin from boiling. Otherwise it will start to stink a lot. You need to heat and stir the substance for about 10 minutes until you get a homogeneous mixture.

How to make silicone at home - copying an object

Prepare a mold that is slightly larger than the item you are copying. Pour some silicone into the bottom and leave to harden. This will be the basis for the item. The thickness should be at least 1 centimeter so that the “rubber” reliably envelops the object from all sides. If the mold is thin, it will tear when the prototype is removed or will not hold its shape at all.

Partially dip the prototype into a bowl of gelatin to remove any air bubbles. Quickly transfer the item and place it on the bottom of the mold, gluing it down. Fill the mold completely with silicone. Homemade resin from the 4th method hardens very quickly - before our eyes. Immediately after cooling, disassemble the mold. Make a cut and carefully remove the prototype.

Mix and pour epoxy resin into the mold. The frozen casting is quite difficult to remove, so you will have to cut the silicone in a circle or completely tear it apart.

Getting rid of silicone

Wash the surface using any detergent designed for grease. You may also need a piece of pumice and a knife to get rid of the silicone. The hardened silicone is cleaned off with a knife, and all its remnants are removed with pumice. This method is only relevant for non-scratch surfaces.

Silicone molds have recently become extremely popular. They are made very simply. If desired, you can even make them yourself. Their service life is very long compared, for example, with gypsum. However, of course, a high-quality mold can only be made from a material with good performance characteristics. What qualities should liquid silicone for molds have and what should you pay attention to when purchasing it?

Types of silicone and master models

Of course, when purchasing material for making molds, you should first of all pay attention to its technical characteristics. Today, only two main types of silicone are produced: coating and filling.

For both materials, master models made of metal and wood, as well as plastic, cardboard, or even just paper can be used in the manufacture of forms.

Coating silicone

This variety is very suitable for making molds. This is a very viscous silicone, applied to the master model with a special brush. An example of such a material is the heat-resistant auto sealant ABRO

Potting silicone

It is also a good material for making molds. When using it, the master model is installed in the flask and poured from above. Liquid silicone for molds of this variety consists of two components: a hardener and a base. Before pouring, they are thoroughly mixed and then placed in a vacuum chamber to remove air bubbles. A very popular material of this type is, for example, Pentelast-708S.

Elongation factor

What characteristics can be considered the most important when choosing a material such as liquid silicone? In principle, almost any variety of it is suitable for making molds. However, it is still worth paying attention to some indicators when purchasing. The most important parameter characterizing the quality of silicone is the elongation coefficient. For modern materials this figure ranges from about 200-1300%. The higher this number, the more the hardened silicone can stretch and the greater the number of castings a mold made from it can withstand.

In practice, 700-800 percent one- or two-component liquid silicone is usually used. It is usually ideal for mold production. Products made from material with this elongation coefficient can easily withstand up to 80 castings. This figure may be smaller or larger, depending on the complexity of the master model configuration.

Silicone viscosity

This is also an important indicator that has a huge impact on the quality of the finished form. Pouring liquid silicone for molds has a very low viscosity. During operation, it easily fills the smallest recesses of the master model. Therefore, it is advisable to use it for the manufacture of molds of very complex configurations.

Viscosity is measured in CPS. For potting materials this figure usually does not exceed 3000 CPS. For comparison: water has a viscosity of 0 CPS, sunflower oil - 500, honey - 10,000.

Other indicators

In addition to viscosity and elongation coefficient, when choosing silicone you should pay attention to:

Work time. The higher this indicator, the longer the material retains its viscosity.

Polymerization time. This characteristic is also quite important. It shows how long it takes for the poured form to reach the stated elongation factor.

Two-component liquid silicone for mold making typically takes longer to harden and polymerize than it does when viscous. This can be attributed to the advantages of the material. After all, when working with it, the master does not need to rush anywhere.

How to use

Liquid silicone is used to make molds as follows.

The master model is fixed to the stand with a drop of superglue and coated with a special release agent. At home, this could be, for example, Vaseline or machine oil.

The stand with the model is fixed in the flask. The latter can be made from almost any material: wood, plasticine, plastic, etc. Disposable flasks are made of paper. Its height should be twice that of the future form. The fact is that during the vacuumization process, silicone foams very much. One of the walls of the flask must be removable.

The evacuated compound is poured into the flask in a thin stream. This is necessary to ensure that as little air as possible gets into the liquid material.

The flask is placed in a vacuum installation for 1-2 minutes. Repeated processing is necessary in order to remove absolutely all the air from the silicone that got into it during pouring.

The form hardens in about 5-6 hours. The final polymerization occurs after a day or three. At the final stage, the mold is removed from the flask and cut in half. After this, the master model is removed from it.

Viscous silicone molds

In this case, a slightly different technology is used. A mold is not used in the manufacture of silicone molds. The master model is simply coated with the material using a special brush in several layers (2-3 mm each) with intermediate drying for 2-3 hours.

Liquid silicone for molds: price

The advantages of this material include not only the ease of making molds. It has earned great popularity due to its low cost. The price of high-quality silicone can range from only 450-750 rubles.

In specialized stores or on the Internet, you should look for silicone intended specifically for making molds. The fact is that today a variety of types of this material are produced. For example, liquid fishing silicone is sold. It is used to lubricate braided threads on gear, which extends their service life and increases casting distance. Such silicone, of course, is not suitable for making molds.

How to make at home

In order to make liquid silicone for molds with your own hands, you need to buy ethyl alcohol and liquid glass. You will also need a plastic bottle and a wooden stick. Since silicone components are quite caustic materials, you should wear thick rubber gloves on your hands. The manufacturing procedure itself is as follows:

Liquid glass and ethyl alcohol are poured into a plastic bottle in equal parts.

The mixture is thoroughly mixed with a wooden stick.

After it thickens, it needs to be removed from the bottle and thoroughly kneaded with your hands.

Silicone prepared in this way resembles plastic, sticky rubber and can be made into any shape.

Silicone molds for the oven

Of course, environmentally unsafe materials cannot be used to make such castings. In this case, liquid silicone for molds is made a little differently:

Three tablespoons of potato starch are poured into a yogurt cup.

Pour silicone sealant there in the same quantity.

Mix everything for ten minutes.

From silicone prepared in this way, you can easily make a simple baking dish. Before pouring the dough, it must be coated with vegetable oil.

Using silicone molds

So, liquid silicone is often used to make molds. The use of products made from “starch” material allows you to bake original pastries, cakes, etc. But how are molds made from ordinary silicone used? Most often they are used to make beautiful products from various kinds of two-component fillings. Any large items are usually not made using silicone molds. Therefore, ordinary medical syringes are used to mix the components of the fillings at home. Next, they are tinted with a drop of dye and poured into the mold through the injection hole stretched by a spacer.

Types of silicone and master models

Of course, when purchasing material for making molds, you should first of all pay attention to its technical characteristics. Today, only two main types of silicone are produced: coating and filling.

For both materials, master models made of metal and wood, as well as plastic, cardboard, or even just paper can be used in the manufacture of forms.

Coating silicone

Potting silicone

Elongation factor

Silicone viscosity

Viscosity is measured in CPS. For potting materials this figure usually does not exceed 3000 CPS. For comparison: water has a viscosity of 0 CPS, sunflower oil - 500, honey - 10,000.

Other indicators

In addition to viscosity and elongation coefficient, when choosing silicone you should pay attention to:

Work time. The higher this indicator, the longer the material retains its viscosity.

Polymerization time. This characteristic is also quite important. It shows how long it takes for the poured form to reach the stated elongation factor.

How to use

Liquid silicone is used to make molds as follows.

The master model is fixed to the stand with a drop of superglue and coated with a special release agent. At home, this could be, for example, Vaseline or machine oil.

The evacuated compound is poured into the flask in a thin stream. This is necessary to ensure that as little air as possible gets into the liquid material.

The flask is placed in a vacuum installation for 1-2 minutes. Repeated processing is necessary in order to remove absolutely all the air from the silicone that got into it during pouring.

Viscous silicone molds

Liquid silicone for molds: price

The advantages of this material include not only the ease of making molds. It has earned great popularity due to its low cost. The price of high-quality silicone can range from only 450-750 rubles.

How to make at home

Liquid glass and ethyl alcohol are poured into a plastic bottle in equal parts.

The mixture is thoroughly mixed with a wooden stick.

After it thickens, it needs to be removed from the bottle and thoroughly kneaded with your hands.

Silicone prepared in this way resembles plastic, sticky rubber and can be made into any shape.

Silicone molds for the oven

Of course, environmentally unsafe materials cannot be used to make such castings. In this case, liquid silicone for molds is made a little differently:

Three tablespoons of potato starch are poured into a yogurt cup.

Pour silicone sealant there in the same quantity.

Mix everything for ten minutes.

From silicone prepared in this way, you can easily make a simple baking dish. Before pouring the dough, it must be coated with vegetable oil.

Using silicone molds

Almost everyone is familiar with such a material as silicone. Men use sealants made from this material. Women often use molds made from it for baking. Many different items are made from it. I wonder if it is possible to make soft silicone on your own at home, as well as forms from it? Yes, you can! Read below to learn how to do it yourself. Production will not take much time, and the simple composition will make it easy to make at home.

What is needed to make silicone

The following materials are required:

Before you start making a rubber-like material, you need to ensure safe conditions. The work must be carried out with rubber gloves, because this material itself is very toxic.

It is also necessary to choose the right place to carry out the work. The room should be good ventilate. The ideal conditions for working on creating silicone products are outdoors. But if this is not possible, then you can do the work on the balcony.

It is also worth knowing the peculiarity of the material - fast hardening. Therefore, it is recommended to produce molding material in small quantities or to carry out all actions quickly.

Other materials can be used to make silicone:

Place sealant in a plastic cup. Add glycerin and paint to it. To do this, it is convenient to use a pipette or straw. Add white spirit. Now you need to mix the mixture thoroughly so that the mass is homogeneous. Silicone is ready! It will remain in a liquid state for about 4–5 hours, and then the pouring silicone will harden, and then it will be difficult to melt it.

First of all, to make the material you need to mix ethyl alcohol with liquid glass in equal proportions. This can be done in any plastic container. During mixing, you need to add dye to the mass according to your own preferences.

Both a wooden stick and a regular spoon are suitable for kneading. After kneading, you will get a mass reminiscent of casting, plasticine or rubber. It can be used in several ways in the future. For example, knead with your hands. You can also put the mass into a regular cooking bag, a gun for construction silicone or a syringe with the necessary attachments and squeeze out the amount that is needed. You can use regular cookie cutters or take some. Or another option is to cast the required shape.

Important! Repeating the shape of an object will only be possible if you apply silicone mass to the outside of the object. To put it another way, apply the mass not into the mold, but from the outside.

Another important point: before applying the rubber mass, the surface should be lubricated with vegetable oil or soapy water.

How to make a silicone mold

For this you will need special material - compound, which consists of:

catalyst (hardening agent)
silicone pastes.

Thanks to these components, any shape can be cast. True, this is not exactly injection-molded silicone (it is more reminiscent of rubber in its properties), nevertheless.

To make an analogue in the form of a silicone mold, you need to do a number of steps:

The required silicone mold is ready!

How to make a mold on a plate

To do this you will need liquid/cast silicone.

The stages of work are as follows:

A plaster or foam plate must be treated with soapy water.
Take a brush and apply silicone to the surface.
Now we need to work out the details. Particular attention must be paid to the top layer.
Wait until the silicone dries.

Now all that remains is to remove the silicone and the required shape on the plate is ready!

How to make a mold from silicone sealant

There are no difficulties here either. You will need any silicone sealant.

Stages of work:

You can also do this. Roll the silicone dough into a ball and press the dough into it. Align the edges. After a few hours, check whether the silicone has hardened or not. If yes, then the workpiece can be removed. The resulting homemade form is ready!

Work very interesting with the material, especially creative people. You can do whatever you want with this material, make various castings for makeup, make an unusual toy or figurine, make a silicone mask, and also use it as glue for crafts. The technology for making complex products, of course, requires certain skills, but simple figures are not difficult to make even for a child. However, if you want to use such a silicone mold for baking, then you should refuse such a desire; it is not suitable for food use. It is better to purchase an industrial silicone mold.

On the Internet you can find many videos that detail how to make silicone and molds with your own hands, as well as how you can replace some components.