Machines for mechanical plastering, the advantages of automating the wall finishing process, typical finishing instructions.
The device and principle of operation of machines for plastering
The device for the mechanical supply of mortar to the wall consists of the following units: a hopper for receiving plaster components, a chamber for mixing the mixture, equipment for supplying mortar from the hopper to the place of work, a product control system, a compressor for air supply.
Depending on the method of supplying the solution to the walls, plastering stations are of three types:
- Manual machine … The mixture is sprayed on the wall with a brush that rotates with a handle. The car is also called a hurdy-gurdy. It is bought for decorative finishing.
- Pneumatic machine … The solution is squeezed out of the hopper by high pressure air generated by a compressor.
- Electric machine … Fully automated products. They are divided into mobile and stationary. The former are equipped with wheels and can be towed. Used for machine plastering of external walls. Stationary products are transported on trailers.
In automatic devices, human participation in the preparation of the mixture is minimal: the master only pours the powder into the hopper and turns on the device. In semi-automatic and manual machines, dry mix and water are added to the mixing chamber manually in certain proportions. Such devices are equipped with cartridge guns for applying mortar to the wall.
It is convenient to machine plaster over 90 m2, in this case, the products will quickly pay for themselves. In other cases, it is better to rent a car.
Surface preparation of walls before plastering
In order for machine plaster to be well fixed on the wall and to be used for a long time, the surface is prepared in traditional ways:
- Remove old covering from the wall and inspect for loose wall sections that need to be removed.
- Clean the surface from oil stains, mold, mildew. Wipe the greasy areas with solvent.
- Remove corrosion from metal parts and coat with an anti-corrosion agent.
- Cut or knock off protrusions that rise 1 cm above the surface.
- Thoroughly clean the wall from dust and prime it.
- Saturate surfaces made of sand-lime bricks, aerated concrete, cinder concrete with fixing and penetrating agents using a spray gun. The liquid hitting the wall under high pressure removes dust effectively.
- Prime the painted surfaces with a brush or roller.
- Cover visible cracks and joints from above with a reinforced nylon mesh with cells of 5x5 mm or 10x10 mm.
Check the curvature of the wall. In the corners of the room, screw in long screws and pull the thread through them along the diagonals of the wall and around the perimeter of the room. Set the threads in a vertical plane using a plumb line. Measure the smallest distance between the cord and the wall, and move all the threads this distance towards the wall, leaving a gap of 5 mm. Check the corners of the room with special patterns or corner rule.
In the corners of the walls, fix the first beacons vertically, place the rest between them. The distance between the bases should be less than the length of the tool (rule) for leveling the plaster. With a rule length of 2 m, the distance between the profiles should be 1800 mm.
Mechanical wall plastering technology
The fully automated plastering machine works as follows:
- The dry mixture is poured into the receiving hopper.
- The water supply hose is connected to the water tap of the apartment or to any container. In the latter case, to pump water, you will need a pump, which is often supplied with the plastering station.
- The product is connected to the electrical network.
- Water and dry mixture in a predetermined proportion, according to the program of the control system, is supplied from the receiving hopper to the mixing chamber, where the auger rotates.
- The mixture is stirred until a pasty state. At the end of the process, pressurized air is introduced into the mixing chamber, which loosens the solution. The mixing process does not stop throughout the working day.
- After saturating the mixture with air, you can plaster the wall.
To obtain a high-quality result, follow the recommendations of the machine manufacturers and plaster mixes:
- Plastering the wall by machine is allowed at temperatures from +5 to +35 degrees. Work stops in case of frost.
- Do not plaster concrete walls with a moisture content of 60%.
- The joints of walls made of different materials must be covered with a polymer mesh.
- First of all, areas are processed near the corners, in all directions. Then the remaining area is leveled.
- There should be a gap of 20-30 cm between the gun (or hose) and the wall. The jet should hit the wall at a right angle.
- The hose can be fitted with a variety of attachments to increase productivity.
- The faster the gun moves, the thinner the plaster layer will be.
- Each layer should overlap the previous one by 50%, which will ensure that there are no grooves on the surface.
After plastering the walls by machine, a procedure for manually smoothing the mortar is carried out using a broad rule, which should be based on beacons. Smoothing should be started after 25 minutes. after applying the plaster, but no later than 40 minutes, when the solution begins to harden. For work, you will also need construction trowels, trowels of different widths.
Cut the mortar 15-20 minutes after finishing smoothing the wall. For the operation, you will need a trapezoidal rule, with the help of which the shape of the surface is completely brought. Lay the rule against the wall and pull it. If the solution is pulled behind the tool, you must wait until the plaster hardens. If you are late with cutting, the rule will not be able to clean the surface of minor defects.
To eliminate minor defects, you will have to use a sponge. At this stage, the corners of the wall are cut and they are putty with a special device for corners. After trimming, check the flatness of the wall. Allowed deviation of a flat surface from flatness within 2 mm by 2 running meters, figured - 2 mm from the shape of the template.
After 1, 5-2 hours after applying the solution to the wall, start filling the plaster. Moisten the surface with cooking spray and let sit for 5 minutes. When the surface is no longer shiny, you can grout. The procedure is performed with a spongy float. After processing, a thin liquid layer of plaster forms on the surface, which is smoothed with a wide spatula to an ideal state. The operation is repeated several times until the desired result is obtained.
The next day, remove the beacons and seal the cracks that opened after them. After use, rinse the stirring chamber and hose with water. For cleaning, you need 2-3 buckets of water.
Safety regulations for machine plastering
When the solution is supplied, a lot of pressure is created in the hose. To avoid injury, follow simple safety rules:
- Wear safety glasses. If dirt gets into your eyes, rinse with plenty of warm water.
- You carry out work in overalls.
- Before switching on the device, check the condition of the hoses, bends and squeezes are not allowed.
- Do not point the hose at people.
- Do not bend the hose, it may burst and injure people.
- Solid objects cannot be added to the machine while it is turned on.
How to plaster walls by machine - watch the video:
There are more and more models of plastering machines, the number of functions is increasing, and the operation is simplified, so the popularity of the device grows with each new development. For a high-quality result, it is enough to study the rules for operating the device and observe them during operation.
