Grinding concrete with a grinder: how to do it correctly, attachments - 4 explanatory sections

Grinder attachment for concrete grinding

For processing to be successful, you need to select a suitable grinding wheel.

Important ! In order not to damage the device, there should be no holes or bumps larger than five millimeters on the floor. So, before using a grinder, it would be wise to carry out initial grinding with a tool more suitable for this purpose.

What kind of attachment is needed for a grinder:

• Material . The most convenient option is a cup-shaped disk. It should contain particles of hard rocks that polish the concrete. In this case, it will be easier to do the job. Using a circle made of sedimentary gravel is also possible, but it will be more difficult and not as effective. If there is impregnation on the floor, it is better to choose an accessory with marble or granite particles.

• Form . To eliminate the first - the coarsest - layer, a “double segment” is used. To clean large pieces, choose a “square”. This prevents damage to the floor and the nozzle itself. For delicate – fine – grinding, the best option is the “boomerang”. If the task is to make the coating glossy at the final stage, then a trapezoidal Frankfurt sandpaper base will become an indispensable assistant.
• For any grinding method, you should individually select accessories with different abrasive sizes. Approximate values ​​are presented in the table.

Recommendation : For safety, it is better to use a device with a rubberized handle, like the TE-AG 18/115 Li Kit, as this prevents slipping.

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How to grind a concrete floor with a grinder

There are two ways:

1. Wet - suitable for a mosaic-type surface or a coating in the form of marble chips. In this case, you will need abrasives that make it possible to achieve a polishing effect.
2. Dry - ideal for concrete, but takes longer. Despite the fact that a lot of dust rises, it is not as disturbing as particles of wet concrete: visibility during processing is much better, so the master can notice and eliminate all errors in time.

Advice : in order not to bother with extension cords, you can purchase a cordless angle grinder, like the powerful 51G203, which is not afraid of overloads.

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Preparation

In order for the result to be satisfactory, you need to check everything first. It is necessary to inspect the surface for cracks, reinforcement or reinforced mesh protruding from it. If there is anything like that, it needs to be removed before sanding begins.

Cracks after shrinkage, various seams must also be pre-sealed. And only when the patched areas of the surface are dry, you can start working.

The floor contains gravel, crushed stone and other particles designed to increase its strength. However, they can pull out the disc if their connection in the solution is not strong enough. Therefore, if the floor is freshly poured, you must wait up to 14 days until the screed dries.

Note : Drilling and other similar types of work are carried out before grinding. Otherwise, we can assume that it was done in vain.

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Grinding process

After the preparation is completed, you can begin the main work. This in itself is not a difficult task: you need to position the circle so that it is evenly in contact with the surface. There is no need to press hard on the tool.

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However, there are some subtleties in how to grind concrete with a grinder yourself:

• First, the surface is coated with a compound that eliminates pores in it: the floor becomes more moisture-resistant and stronger.
• For the most even, shiny effect, you need diamond discs with a high density - from 400.
• To make it easier to collect garbage, a casing would be helpful: it will prevent concrete dust from flying in all directions. There are options that allow you to connect an angle grinder to a vacuum cleaner.

Recommendation : It would be good to choose a tool with dust protection, like the MB 2400PA. Such models last longer.

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Why grind a concrete floor?

Recently, technologically advanced pouring and installation of a concrete floor for laying floor coverings cannot be imagined without grinding. High-quality work will make the coating practical. It will reduce the cost of money and effort on leveling the floor surface, installing parquet or laminate, and does not require periodic restoration.

The cup attachment is used for preliminary preparation of the base for laying new floor coverings

In addition, it provides the following capabilities:

• use concrete pavement in shops and warehouses without finishing floor material;
• will increase strength to mechanical loads and abrasion;
• will increase the water resistance of the coating and will not allow chemicals to corrode the structure;
• Gives a shiny look that can be used in any interior.

Attention! If a fresh coating is being sanded, then additional steps related to the removal of lime milk are not performed. When sanding an old floor, the old layer is removed.

Grinding is used to provide a flat and smooth surface for treatment with strengthening compounds or coating with paints. In this case, grinding is done on the new coating in two stages:

1. After 3-5 days after pouring - pre-treatment.
2. After complete hardening of the composition - final processing.

Using a tool with a special disc attachment for grinding concrete on a grinder will solve a number of problems in cleaning and eliminating minor defects:

1. Cracks.
2. Chips.
3. Surges.
4. Ripple.
5. Notches.

Sanding is used to restore the coating. Especially when leveling work is carried out on an old floor. The first step is to remove the worn layer, and then use an angle grinder. If this is not done, the strength of the leveling layer will decrease.

Various cup shapes for angle grinder equipment

An unpolished concrete floor absorbs moisture in large quantities. If the coating is located outdoors or in an unheated room, then at subzero temperatures the concrete will freeze, and the moisture in it will increase in volume, which may cause cracks.

Safety precautions when working with an angle grinder

To avoid damaging the instrument and harming yourself, you must follow these rules:

• Make sure the angle grinder is in full working order before you begin.
• There must be enough light at the work site.

• The user should wear thick clothing. Sleeves should not interfere with working with the device, and the clothing itself should not be in contact with the floor.
• Care should be taken to protect the respiratory tract, eyes and hands with gloves, a pair of goggles and a respirator.
• You need to let the device rest at least once every 15 minutes to prevent it from overheating.

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As you can see, an angle grinder is very useful for concrete. You just need to choose a suitable grinding wheel for it and act carefully.

Tool selection

For home use, a regular grinder with a power of 1.2-1.5 kilowatts is perfect. The disk is selected with a size of 150-180 mm. You should also take care of a water cleaner or industrial vacuum cleaner with a cover so that dust does not get into the air at all or, if it does, it is immediately removed into the dust bag.

If everything is more or less clear with the choice of an angle grinder, then with the choice of attachments everything is not so simple. Exist:

• Disks. Discs are an excellent option for fine surface finishing. Like any fine machining disc, the discs wear out quickly.
• Cups. These are disks
• Frankfurts are used only for the final stages of wet processing.
• Milling cutters. Cups are steel discs with welded elements.
• Models from the manufacturer. Each company strives to come up with something of its own, and therefore many models with strange names exist on the market and will always exist

Conclusion

To grind concrete surfaces of small areas, it is not necessary to use bulky construction equipment. All work can be done using a manual grinder, for which you should put a special diamond wheel on it. The video in this article will help you find additional information on this topic.

Sources

• https://zamesbetona.ru/obrabotka/shlifovka-betona.html
• https://kvartirnyj-remont.com/shlifovka-betona-bolgarkoj.html
• https://1nerudnyi.ru/shlifovka-betona-bolgarkoj-01/
• https://laminatepol.ru/19524-nasadok-dlya-shlifovki-betona-na-bolgarku.html
• https://stroy-podskazka.ru/instrumenty/bolgarka/nasadki-dlya-shlifovki/
• https://tehnika.expert/dlya-remonta/bolgarka/kak-shlifovat.html
• https://masterabetona.ru/operacii/95-shlifovka-betona-bolgarkoj

Diamond blade - what is it?

For the manufacture of diamond discs, high-strength hardened steel is used that is resistant to various temperatures. The cutting element of the circle is a diamond coating in the form of chips, which is located on its outer edge and is made as a solid segment. When cutting concrete and other materials, the diamond chips begin to wear off, and therefore the wheel itself gradually wears down. Of course, diamond discs grind down very slowly, because after erasing one diamond layer, another working layer appears on the surface of the disc, which significantly extends the operating time of an expensive grinding wheel.

Grinder and grinding disc

Preliminary stage

If there are any coatings on the concrete surface, you should try to remove them. You must first level the plane. This can be done using a 3D ruler. If bumps, potholes or holes are detected, it is necessary to increase the number of diamonds. It is necessary to carefully examine the deformation-shrinkage seams and cracks. If there are any, then they need to be sealed and problem areas additionally sanded. In order to check the hardness of the floor, you need to try working a small area with a grinder.

Before you start grinding concrete, you need to make sure that there is no reinforcement or reinforcing metal mesh in the top layer. If such material is available, then it needs to be cut out with a grinder.

Grouting fresh screed

This technology is used to create durable, wear-resistant floors in industrial and commercial premises, and hard coverings in open areas.

A concrete grinding helicopter is a manual or self-propelled trowel with a diesel, gasoline or electric engine. With its help, the screed is processed 4-20 hours after installation. This allows the top layer to be compacted; cement-based toppings are used to enhance the effect.

After rough grinding, finishing is performed within 10-16 hours. In this case, a dust-removing impregnation is rubbed into the surface of the concrete. Helicopter processing of fresh screed makes the floor surface smooth and resistant to cracks. For a decorative effect, pigments are used in the topping.