Features universal silicone sealant

It has been a very few years since when putty, bituminous mixtures and self-made mastic were used for filling cracks, joints, seams, for bonding and combining. The emergence of such a substance as a sealant made of silicone, at once solved a lot of problems because of its universality.

Silicone sealant is a dense, viscous antibacterial and elastic hydrophobic mass. Sealants are environmentally friendly mixtures that are safe for human and pet health.

Here are some basic characteristics:

• temperature regime of use from -40 to + 120 ° С (for heat-resistant species up to + 300 ° С);
• can be used outdoors - resistant to UV rays;
• high degree of hydrophobicity;
• highly adhesive to the main types of surfaces;
• ambient temperature when applied from +5 to + 40 ° C;
• maintains the aggregate state when the temperature difference from -40 ° C to + 120 ° C;
• can be used at temperatures from -30 ° C to + 85 ° C;
• storage temperature: from + 5 ° С to + 30 ° С.

Composition of silicone sealant:

• silicone rubber is used as a base;
• the amplifier provides a level of viscosity (thixotropy);
• plasticizer is used to give elasticity;
• the vulcanizer is responsible for changing the initial properties of the pasty form into a more plastic, rubber-like;

• the dye is used for aesthetic purposes;
• fungicides - antibacterial substances - prevent the development of mold fungus (this property plays a large role in rooms with high humidity);
• To improve adhesion, various quartz-based additives are used.

Table of approximate calculations of volumes.

Here are some negative aspects of the use of sealants:

• wet surfaces are inefficient to handle;
• if the color is not added initially, some types of sealants cannot be painted;
• poor adhesion to polyethylene, polycarbonates, fluoroplastics.

There are several areas where silicone sealants are used:

• at isolation of drainpipes, at repair of roofs, a siding;
• when closing the joints of drywall constructions;
• with glazing;
• when sealing openings of windows and doors;
• during the sanitary works in bathrooms and other rooms with high humidity.

Sealants are divided into one-component and two-component.

Single components are classified by type:

• alkaline - based on amines;
• acidic - based on acetic acid (for this reason it is not recommended to use them in combination with cements and a number of metals because of the corrosive activity of such sealants);
• neutral - based on ketoxime, or alcohol.

The composition of such sealants, as a rule, includes various additives:

• colorants;
• mechanical fillers to increase adhesive properties;
• extenders to reduce viscosity;
• fungicides with antibacterial properties.

Two-component sealants (another name - silicone compounds) are less popular and diverse. They are mixtures used only for the needs of industry.However, if desired, they can be purchased in regular retail chains. Characterized by the fact that their layer can be of unlimited thickness, and they cure only by a catalyst.

Sealants can be divided by the scope of their highly specialized use.

• Automotive. Used for car repairs as a temporary replacement for rubber pads. Chemically resistant to engine oils, antifreeze, but not gasoline. They have a low degree of fluidity, short-term refractories (up to 100 310 ° C).
• Bituminous. Mostly black. Used in the repair and installation of various parts of buildings and structures. Also used when laying drains.
• Aquarium. Used in aquariums. Usually colorless, high adhesion. Connect and seal the joints of the surfaces of aquariums and terrariums.
• Sanitary. One of the components is a biocide - antifungal agent. Used in plumbing. Usually, these are white or transparent sealants.

First of all, the proportions of the components should be estimated.

Sealant should consist of:

1. silicone - 26%;
2. rubber mastic - 4-6%;
3. thiokol / polyurethane / acrylic mastic - 2-3%;
4. epoxy resins - no more than 2%;
5. cement mixtures - not more than 0.3%.

Excess sealant can be removed from the surface with:

• white spirit (until the sealant has hardened);
• special flushing agent (it will completely dissolve the sealant);
• soaps and rags;
• knife or spatula (with a certain risk of damage to the surface).

The rule applies to all items: it is possible to dissolve or erase only a layer of insignificant thickness. In all other cases, you will have to resort to paragraph 4.

When sealing the seams, we recommend the following sequence of actions:

• we clean the work area from all contaminants and dry (metal surfaces are additionally degreased);
• insert a tube with a sealant into the silicone gun;
• open the package and wind the dispenser, the cross section of which is determined by cutting the tip, depending on the required width and volume of the seam;
• if we are talking about the processing of decorative parts,masking tape protect them from accidental ingress of sealant;

• apply sealant slowly evenly;
• after the seams, remove the masking tape;
• immediately after the application is finished, remove the unnecessary sealant with a wet material until it hardens.

Sealant cure depends on various conditions: type, layer thickness, humidity, ambient temperature. The seam surface hardens in approximately 20-30 minutes, which does not mean that the seam is fully ready for operation. As a rule, the time for complete solidification is 24 hours.

When working with silicone sealant be sure to follow the following recommendations:

• it should be stored at medium temperature;
• keep away from children;
• the storage period is indicated on the package;
• Silicone in the eyes and on the skin is not recommended, the site of contact should immediately be washed with cold water;
• if an acid-based sealant is applied, which in the process of work produces vapors of acetic acid, then individual PPE (respirator, gloves) should be used, and the room should be carefully aired to avoid irritation of the mucous membrane.

Of course, preference is better to give solid and proven brands of manufacturers, such as Hauser, Krass, Profil, or Penosil. The most common packaging options: tubes of 260 ml, 280 ml, 300 ml.

When choosing between “universal” or “special” compositions, give preference to the second option, if you have an exact idea of ​​the surface material where this substance will be applied.

Keep in mind that specialized sealants are not as resilient as neutral ones.

How to work with sealant without using a special pistol is described in the video.