Magnesite putties (MP) – are putties specially designed for magnesite boards. Their base consists of a magnesia binder (magnesium oxide), the same as in sheets, it guarantees a maximum affinity of the underlayer (magnesite sheet) and the coat (putty). Due to that, the maximally possible adhesion has been achieved between the given construction materials, as well as practically equal interaction with environment.
The major purpose of magnesite putties lies in leveling and repair work of magnesite boards, and sealing of joints between them. When leveling a surface, magnesite putties can be used as a starting and finishing coat layer.
Besides their major application, MP can be used for leveling of other construction surfaces, for example, brick, cement, concrete ones at the age of more than 28 hours. MPs are also recommended to be used as finishing when high antibacterial conditions are created in a room.
Main consumer properties of MP
High consumer properties of magnesite putties are conditioned by their use in production of a great quantity of binding substances – magnesium oxide which refers to a type of complex binders. This fact explains high strength of magnesite putties, good antiseptic and antibacterial properties, as well as the resistance to rapid temperature and humidity falls.
- Ecological aspect: magnesite putty does not contain harmful substances and additives, it is safe for people and food products.
- Antiseptic and antibacterial properties of substances forming a magnesite putty composition prevent from mould, fungi and insects.
- Incombustibility: incombustible material.
- Humidity-resistance: resistant to the influence of moisture, steam, dampness and direct contact with water.
- Strength: after its final hardening (28 hours), MP is characterized with good strength properties, in terms of these indicators they can be compared to magnesite boards.
- For inner and outer work
- Can be used as a starting and finishing layer
- High adhesion to mineral bases
- Reinforced with micro fibers
- Flexible, easy at application to surfaces of constructions
- Fine-dispersed (particles 0,2 mm)
- Thickness of a layer per one application is – up to 2 mm.
Sphere of application
Main sphere of application is leveling and repairing of magnesite boards, as well as sealing of joints between them.
It can be used in inner and outer works for high quality preparation of mineral surfaces (magnesia, concrete, cement, brick, gypsum bases for finishing coat), and for sealing of joints between mineral board finishing materials.
Thickness of a layer per one application is up to 2 mm. It can be used for filling of small cracks and holes up to 3 mm depth.
After hardening it can be paint with aqua-dispersive paints, wallpapered, tiled with decorative materials.
It is not designated for repairing of floors. The application in places of constant humid air influence can lead to salty appearances on a surface.
It is recommended to form a finishing layer in rooms with high sanitary and epidemiologic requirements.
Content and packaging
To improve quality indicators, magnesite putty is manufactured as two-component and is packed into two packages.
- Package 1: dry mix of white colour, packed in a bag. It consists of magnesia binder, filler and modified additives.
- Package 2: sealer – special liquid, poured into canisters. Sealer – is a salt solution of a special concentration with modifiers and reinforcement fibers.
After mixing of these two components a mortar is formed, similar to a cement one, which hardens in dry air conditions with a certain period of time (not more than 40 minutes).
Preparation of a base
The base should be strong, dry and minimally moistened (at high temperature and low air humidity). The base should be cleaned from dust, unfixed particles, oil spots and other substances which could worsen adhesion before the application of the mortar mixture. The base should be without hollows, holes and cracks of more than 3 mm depth. All precedent varnish coatings should be removed. Not strong bases and bases with high water-absorbance should be preliminary treated with coatings of deep penetration. Bases with smooth surface should be treated with abrasive paper to get rough surface.
Preparation of mortar mix
To prepare putty, you have to mix, by hand or with the help of a mixer, for example, a low-speed drill, the content of Package 1 (dry mix) and Package 2 (sealer) in a proportion of 1 kg of a dry mix with 0,5 liters of a sealer. It is recommended to add the dry mix from Package 1 (for example, 100 g) into the sealer of Package 2 (correspondingly 50 ml (61 g)), stirring intensively to a homogeneous state.
It is necessary to prepare such quantity of putty which will be used within 20-30 minutes, because the putty thickens quickly, it starts to harden in 40 minutes.
If less binding putty is needed, it is allowed to add water into mixed putty, but not more than 100 ml/1kg of dry mix.
Procedures of application
Leveling of a surface is performed by a traditional method. It is recommended to use a caoutchouc and a stainless steel putty knife or a plastic one.
The maximum allowable thickness of a layer per one coating should not exceed 2 mm. The leveling of 2 mm is done by multiple coating with putty layers using the technology of layer by layer application of the putty and fixation of glass fiber mesh for reinforcement.
On extremely water absorbent surfaces with a layer thickness of about 0,5 mm, the leveling should be done within one minute.
To seal the joints (2-8 mm) between magnesite boards, it is recommended, after putty application into a joint, to fix a calico strip with its smoothing on a fresh layer of putty. Just after the loss of stickiness, to apply finishing layer of the putty diluted to a minimal viscosity.
To enhance smoothness, 1-2 hours after the application of a leveling layer (when the putty layer loses its stickiness), the coated surface is smoothed with a soft moistened (but not wet) sponge (for example, a kitchen sponge from foam polyurethane).
After that, a wet layer of the putty is leveled with a plastic putty knife. If needed, the operation can be repeated several times, but before the moment of achieving of high hardness, when putty, wet because of water, does not become flexible any more. After these procedures, the smoothing of the surface is not required.
If the smoothing of the surface is needed, work is performed just after the loss of stickiness by the putty layer (1-2 hours), otherwise the putty acquires high level of hardness, and this work will be hard to fulfill. The smoothing is done with the help of a fine abrasive paper or tungsten mesh. Wash tools with warm water just after the end of work. Hardened putty can only be removed in a mechanical way.
Outer conditions of work performance
During the period of the putty hardening, to avoid fast drying, influence of direct sunlight and subzero temperatures. The recommended humidity and temperature for hardening is 70% and 10-25°C respectively not less than 16 hours.
|Quantity of the sealer, needed per 1kg of dry putty, l||0,5|
|Time of use of the mixed mortar, min, not less than||30|
|Maximal quantity of water used in the dilution of the prepared mortar, for 1 kg of dry mix, ml||100|
|Recommended thickness of a layer, mm, not more than||2|
|Filler value, mm, not more than||0,2|
|Crush strength limit in 28 days, MPа, not less than||7,0|
|Tensile strength limit at bending within 28 days, MPа, not less than||1,0|
|Cracks-resistance||Absence of cracks on a layer of 2 mm thickness|
|Vapor permeability, mg/m*hour*Pа, not less than||0,05|
|Contraction, mm/m, not more than||1,5|
|Adhesion strength with a base in dry air conditions, MPа, not less than||0,3|
|Frost-resistance, cycles, not less than||75|
|Approximate consumption of dry mix per layer of 1 mm thickness, kg/m2||1,5|
|Approximate consumption of dry mix per 1 liter of filled volume, kg||1,5|
To obtain a maximal quality mortar mix, the proportions, indicated in this instruction, should be strictly followed. The addition of water to the mixture, beyond the specified maximum, is not allowed.
To mix the putty with other fillers and binders is forbidden.
In the case of the use of putty in conditions that are not specified in this description, contact the producer.
Terms and lifetime
Shelf life – 6 months if stored in a cool, dry place in sealed original packaging. Do not store in open or damaged packaging. It is prohibited to freeze the product, to store it near heating appliances. Do not store the putty under the weight. After the expiration of the warranty period it is allowed to use the material only after the verification of its shelf life.
Avoid getting of the putty or its components into eyes. In the case of the contact with eyes, rinse eyes with water and if necessary address a doctor.
The rest of non-used dry mixture should be mixed with a sealer until you obtain a thick dough. Solidified mortar is ecologically friendly and disposed as construction waste. Packing is disposed as household waste.
Advantages of magnesite putty use
- The main technical advantage of magnesite putties is their strength comparable to magnesite board strength, and high adhesion, first of all, to magnesia bases due to the identical binders in their content.
- MPs are ecologically pure materials with strong antiseptic and antibacterial properties preventing the excessive development of bacteria, viruses and other unhealthy microorganisms. The presence of magnesium salts in magnesite putty prevents the development of colonies of insects and rodents.
- Application of MPs contributes to the creation of a favorable climate for a man in the room by means of the emission of air ions into the atmosphere (lung negatively charged molecules). Effect of salt caves.
- MPs are non-combustible materials.
- Short period of hardening can reduce the time and cost of putty work.
- High adhesion to mineral substrates.
- Improved durability.