Preliminary activities
Grinding is getting rid of minor defects, therefore, before starting the process, you will have to attend to getting rid of major flaws:
- These are different types of tubercles. If it is noticeable with the eye, then it is better to cut it off with a grinder. The maximum permissible tubercle size is 1 mm.
- Seams. The seams should not be visible. No amount of sanding will get rid of a seam or dent in the screed. In this case, you will have to re-fill or pour an additional layer on top.
- Depressions. It is better to cover the depressions. There should be no visible cracks, depressions, dents.
- Mark the areas where sanding will take a little longer, i.e. irregularities of the screed itself. To do this, you need to use the level.
- After that, you need to check the voltage in the network. From a sharp jump or fall, the grinder may fail, the grinding may fail, and the hand may tremble. Because of this, it may be necessary to create a floor from scratch.
- The floor itself must be tested for strength. To do this, you will have to make a test run with a grinder. If the floor is crumbling too much, you need to take a nozzle with a smaller grain size or re-fill the floor.
It is very important to use crushed stone of fine fractions in the pouring, since no discs are enough to grind a large stone, which will surely be in the most inappropriate place for this.
If a small but visible crack has formed, then with the help of a diamond disk, the crack is expanded and sealed flush with the floor level. Grinding can only be started after such fillings have dried.
The expansion is carried out to a depth of 10 cm, after which a piece of concrete is removed, the surface is treated with a primer, and only after that a layer of embedding is applied.
Technology and stages of the grinder grinding process
- Preparation: cleaning of surfaces, marking of grinding, sealing of seams, sawing of protrusions, etc. Be sure to take out all the debris before grinding, since it will be extremely difficult to do this during work. Nothing should distract you from your work. The cover on the grinder must be put on in advance, as well as turn on and prepare the vacuum cleaner. The attachment of the attachments to the grinder is checked.
- Rough grinding. Rough grinding is performed 3-5 days after the screed was monolithic. It is necessary to remove 2.5-3 cm in order to get rid of the most coarse blemishes, cracks and protrusions. After checking the tool, grinding is performed. The rule of 15 minutes applies to the grinder: work is carried out for 15 minutes, after which the tool turns off. You can turn on the grinder again only after the disc has completely cooled down. The heating temperature of the nozzle should not be felt at all. That is, the disc will reach a temperature approximately equal to the ambient temperature.
- The next step is impregnation. Special construction impregnations are used to strengthen concrete. The impregnation is literally poured onto the surface of the screed and slightly leveled over its surface. Concrete will absorb this composition for another 10-15 days. The amount of impregnation is calculated in advance. Do not be surprised if, immediately after pouring, a certain amount of liquid remains above the concrete surface. Over time, the concrete will absorb it too.
- Only after this is the final processing carried out. For this, a thinner disc with a higher abrasiveness value is taken. If a disc with abrasive 25 is used for roughing, then for the final one you will have to use a nozzle with an indicator of 40. The glossy effect is revealed only when using tools with abrasive 1400-1500.
How is concrete grinding with a grinder
Sanding the floor is not that difficult. The main thing is attentiveness when correcting draft defects, adherence to safety rules and the correct choice of tools.
How to Cut Concrete with a Grinder Without Dust
At one time, repair or construction, when it is required to carry out work on concrete: cut out an opening for a window, a niche, gouge walls for wiring. The masters understand how many small particles appear with all this. Cleaning after similar activities is very laborious. We propose to figure out whether it is possible to cut concrete without dust and how to organize the myth process.
Concrete is a strong material, therefore it is quite difficult to work with a child. To perform cutting, in most cases, use an angle grinder (angle grinder). the myth is not just a tool known in everyday life as a "Bulgarian".
A diamond wheel is used for the attachment. Depending on the design features, they are divided into several varieties:
- segment,
- solid;
- combined (turbocharged).
Option 1 is a solid base with a segmented edge. Such a circle is distinguished by a low price, alas, it is not very suitable for performing work with strong materials. It must also be borne in mind that it is used only for dry cutting. The solid disc has a continuous diamond edge, so no chipping occurs during operation. Such a nozzle heats up rapidly, therefore it must be cooled with a continuous water jet.
The combined turbo-diamond disc, as it is also called, is universal. It can handle critical loads and is even suitable for cutting reinforced concrete.
Before buying a suitable type of attachment, you need to figure out what material you will have to work with. Reinforced concrete is reinforced with metal rods, which during the course of the cutter can hit. If a deepening of more than 10 cm is meant, use discs of increased strength, in other words, turbocharged ones. The freshest concrete is more abrasive, over time the material hardens, its strength increases. the myth factor should also be taken into account when choosing a circle for cutting.
Segments of the disc are attached to the blade with silver solder or laser welding. The 1st option is not just suitable for wet cutting, the 2nd is used only for dry cutting
When choosing a suitable diamond wheel, pay attention to its diameter, which should be suitable for the characteristics of angle grinders. The fundamental aspect is also the rotational speed of the disk.
It is better if it is higher than the very likely indicator stated in the technical properties of the "grinder". This will provide a better mode of operation.
The introduction of water allows you to cut concrete with a "grinder" without dust and overheating of the tool. The development allows you to immediately solve several problems:
- increase the resource of the diamond tip,
- avoid dust formation,
- increase the speed of work.
One way to keep the water flowing continuously is to secure the hose so that the liquid flows onto the disc. If there is no plumbing in the working area, an assistant can be involved in the process. He will use a simple plastic bottle fixture to wet the wheel. Immediately moisten the incision site with liquid
This must be done carefully so that water is not poured into the instrument.
The method is not very applicable in high-rise buildings, as there is a risk of flooding the neighbors from below.
A grinder with an integrated vacuum cleaner allows to get rid of the small particles of material formed during the cutting with the "grinder". But what to do if there is a need to cut concrete with ordinary tools without additional options? The most common solution would be to purchase a casing for a vacuum cleaner separately or make a device at home. Of course, involve an assistant who will collect the particles formed during the sawing with a vacuum cleaner.
You can make a comfortable attachment from an ordinary plastic canister, when a car is often sold with a "frost-free" car. To carry out the work, you will need a construction cutter and a container of a suitable size, the neck of which is engaged will fit in diameter to the vacuum cleaner hose.
The production sequence is as follows:
- Fitting dimensions are cut from 2 sides so that you could simply change the direction of rotation of the disc.
- A slot of a suitable size is made under the circle.
- For attaching the cutter "grinder" cut the next hole.
- The hose is connected to the neck of the canister and reinforced with a transition ring with a clamp.
- The "Bulgarian" is put into the casing and the elements are connected to our client.
- The unused opening is closed with a lid.
How to grind with a grinder
Remember that sanding is always associated with a lot of dust. When preparing for sanding, do not forget about yourself! A face shield and a respirator are the best helpers when sanding. You can also find an option where the mask is combined with a good respirator.
The respirator filter will clog up very quickly, so you need to prepare several pieces at once for quick replacement. Only after thorough preparatory work can you start grinding.
Grinding wood + (Video)
Wood is a unique material. It is polished by hand quite well, but with a grinder you can achieve very good results. Some snobs argue that you cannot grind with a grinder at all, but this is from ignorance and inability.
The main secret is that the grinder is used at minimum speed. If the grinder has a speed switch, then there will be no problems. At high speeds, sandpaper will clog very quickly and very tightly with wood. In this mode, it will not be enough for five minutes of work. The optimum speed is no more than 6000 rpm.
Another secret is not to sand with the entire area of the wheel. If you sand the entire surface, then circular marks will remain on the wood. So that no traces of sandpaper remain at all or they would be minimal, it is necessary to grind only with the upper sector of the circle. The movement of the machine should be along the grain of the wood.
With this method, you can get excellent results when sanding the lining. The board becomes smooth and does not retain tool marks. Do not just get carried away and change the emery pads on the circle in time.
The frame is polished in a similar way. Here, it is desirable that the support plate is thin around the edge. With such a plate, it will be easier to sand narrow places where the logs meet. Otherwise, this work will have to be finished with a chisel.
We work on concrete + (Video)
If it was not possible to purchase a branded protective dust cover with a nozzle for a vacuum cleaner, then you can do it yourself. To do this, take a used putty or glue bucket with a diameter slightly larger than the grinder's circle. Cut off the bottom part at a height slightly larger than the assembled sanding part.
We cut a hole in the bottom for installation on the gearbox and a hole for a plastic plumbing corner bend. Now we connect the hose of the vacuum cleaner to the nozzle and work calmly.
The grinding wheel must be dimensioned for stone processing. It is preferable to grind concrete and concrete surfaces with the entire surface of the wheel. This will save machining time and flatten the surface well.
When sanding a concrete floor, it is necessary to constantly control the plane with a building ruler, because, due to the different density of concrete, indentations can be made. For the processing of butt joints between concrete fillings, it will be sufficient to achieve one level combination.
Sand concrete floors and surfaces well with a Matrix diamond cup. If the grinder is 150 mm, then the cup is 125 mm.
Grinding metal surfaces + (Video)
Metal is ground according to different requirements.Most often, the metal is ground for painting or for further polishing. The main tool is recognized as a support cup with replaceable emery pads. The selection of sandpaper depends on the degree of processing and on the state of the metal.
When sanding, you only need to work with part of the disc. There should be no untreated areas on the surface.
It is desirable to prime the treated surfaces of ordinary steel with a primer. Moisture in the air can coat metal very quickly and cause rust.
Tool selection factors
You cannot do without the use of a special sawing tool. When choosing it, it is necessary to take into account a number of factors:
- The location of the structure and its dimensions. For thick walls and concrete floor screed, different tools will be used even if the properties and composition of the stone are the same.
- The composition matters: the harder the filler, the more difficult the cutting. As a coarse aggregate, granite crushed stone can be used - one of the hardest, or crumbs of softer stones. The quality and size of the sand should be evaluated - the finer it is, the denser the concrete. Large unwashed creates a looser structure of the stone.
- Age and condition of structures. The peculiarity of concrete is its strength gain over the years. The cement, which makes up the bulk of the composition, only adds strength when absorbing moisture. In combination with fine sands, this stone becomes very hard. However, dilapidated structures, which are exposed to chemical environments, lose their former strength and hardness.
Preparing the workplace
To work with concrete products, you need to choose a place that is far from living quarters. It must be remembered that in addition to the unbearable soundtrack, sawing concrete is accompanied by the release of a huge amount of dust, which is dangerous not only for humans and pets, but also for household appliances and furniture. It is advisable to coordinate your occupation with neighbors who are not always happy with such actions in the immediate vicinity of their home. If cutting is carried out in an apartment or house, you must definitely take care of protecting the interior elements with a cloth, thick paper or plastic wrap.
Nozzles and discs for concrete for grinders
Each tool used in conjunction with an angle grinder (angle grinder) is designed to perform the operations for which it is designed. The right choice contributes to efficient and safe handling of discs and attachments.
Cutting discs
For working with concrete, diamond cutting wheels are used. These are discs made of hardened, hardened steel with diamond-coated cutting edges.
Such nozzles differ in the following design features:
- Cutting edge. It can be solid or with various slots. The segmentation improves the air cooling efficiency during operation.
- The grain size of the diamond coating and the method of spraying. The most reliable methods using laser welding and thermal joining. Soldering with silver allows you to work only with water cooling. The electroplated diamond edge cuts only soft natural stones.
- The outer diameter of the circle. Install discs of a suitable size. Working without a protective cover is not only dangerous: an oversized attachment leads to premature wear of the gearbox.
The material can only be cut with a diamond tool in a straight line. Curvilinear cutting increases the stress on the cutting edge, as a result of which the diamonds are destroyed.
Grinding discs for concrete
Concrete is ground to eliminate coating defects. They use diamond wheels, which have a high abrasive ability and a long working life. Sometimes carbide-tipped discs are called diamond discs, the characteristics of which are lower. Work efficiency is largely determined by the grain size of the working surface.
Depending on the concentration of diamonds, discs for grinding concrete are distinguished:
- grain size 40-80 (for pre-processing);
- indicators 100-120 (for leveling the surface);
- grit 180-240 (for polishing).
The tool is a steel circle with brazed segments. Diamond powder is fixed on them with a special binder. It keeps the diamonds from being destroyed by the centrifugal force that occurs during rotation.
The designations on the discs consist of 2 or 3 numbers. The first number indicates the outer diameter, the second indicates the size of the bore. The third number is not always present, it denotes the thickness. For a grinding tool, this parameter does not play a big role.
Stripping and roughing nozzles
These attachments look like cups or circles. There are cutters and diamond discs. Twisted metal brushes are located around the cones. They rip off metal and stone. The diameter of the wire differs depending on the purpose (stripping or stripping).
Purpose of the angle grinder
The peculiarity of the machine is the ability to process not only flat surfaces, but also chamfers. This is achieved thanks to the angular placement of the working disc.
The device is universal, it is used to perform many works:
- The main operation for which the angle grinder is intended is grinding. Wide grinding wheels are used. Processing the ends with an eccentric sander is difficult, but affordable for a grinder. The surface is sanded with or without water cooling.
- Polishing with a grinder is also possible. To do this, use special diamond-coated polishing discs.
- Another operation performed with a grinder is cut. The unit is not well suited to work with thick materials. Concrete or thick stone should be cut with special machines that have a water-cooled working wheel.
- The angle grinder easily cleans surfaces, removing dirt, paint, mastics, adhesives, building mixtures with the help of roughing nozzles.
The grinder can be used instead of a wall chaser. With a cutting disc, grooves are cut for an electric cable, pipelines.
Shape and number of segments
The quality of the work performed depends on the type and number of segments. There are cups for roughing, rough sanding and fine polishing of surfaces. By the shape of the cutters, the nozzles are classified into the following types:
- Double segment
- Square
- Boomerang
- Turbo
- Typhoon
In the design of each type, a certain arrangement of segments is provided, which affects its working properties.
The Double Segment diamond cup is a double row tool for removing large defects in concrete products. Large beads or raised seams are easy to sand with this good abrasive nozzle. Segments arranged in a circle in two rows quickly and efficiently process stone or sandstone. Sometimes builders use a nozzle to reduce the thick layer of the screed. But with the help of the "Double segment" it is impossible to achieve perfect smoothness, the screed becomes rough, therefore, for the final sanding, you need to use a different attachment.
Boomerang
The tool got its name due to the similarity of the shape of the diamond segments with the boomerang. The tool is applied for finishing concretebecause the cutters use fine-grained diamond grit. After processing, the screed becomes perfectly flat. The small mass of "Boomerang" makes it easy to use, it is often installed on a grinder, since it has a small mass. The popularity of this type of cups is due to their high performance, which is almost twice that of other types of diamond discs. The choice of this particular instrument is also influenced by its lightness and stability.
Square
Diamond cups "Kvadrat" are used for roughing concrete surfaces.The effectiveness of the tool allows it to be used to remove large beads and protruding seams. Diamond cutters are made in the form of squares. The increased thickness of the working segments and the large distance between them allow not only to level the surface with roughness, but also to remove any protruding parts on the concrete. Therefore, grinding with the “Square” attachment reduces the time for rough processing of concrete and brick coatings, extending the service life of diamond segments.
"Square" have a lot of weight, so you can handle the material with a tool without much effort.
After passing through the diamond cup, the surface remains rough, which gives it high adhesion properties
This is especially important for adhesion to the applied coatings, especially polymeric ones.
Turbo and Typhoon
The diamond cutters of these bits are located in a circle on the working surface perpendicular to the direction of rotation. The minimum distance between them creates an almost solid ring. The appearance of the Turbo and Typhoon discs resembles corrugated fabric. Many segments smoothly polish the surface, so the products are used for finishing grinding on small areas and for shaped stone processing. The attachments can be used to chamfer and shape edges, as well as polish small curves on workpieces.
To perform small operations, you can purchase cups "Turbo" and "Typhoon" of small diameter - from 100 mm. The discs are distinguished by their durability, high productivity and processing accuracy.
Grinding attachments
The key to good grinding is a high-quality and correctly selected abrasive element in accordance with the type of surface to be treated.
Grinding discs
Disc grinders for grinding concrete are the most popular. Depending on the degree of processing, they are of two types:
turtles. This type is applicable for surface finishing. They are distinguished by a flexible base on which fine diamond grit with the addition of polymers is applied. They are quite convenient to use and quick to replace, thanks to their Velcro fastening system;
Cups
Various concrete grinding cups are a type of grinding wheel used to remove thicker concrete. The types of cups differ depending on the processing level:
- double segment - for removing the first thick layer;
- square. If you need to remove large chunks of concrete during the roughing process, this is the best bowl to use. It allows you to shoot decent segments without losing quality, both the coating itself and the attachment;
- boomerang - provides a more delicate grinding of the finishing layer due to fine abrasiveness.
Frankfurt
If you want to gloss a concrete finish layer to a mirror finish, then a trapezoidal frankfurt is what you need. It has an emery base of various sizes, which allows you to achieve completely polar results of work.