Grinding machine for a car - we understand the nuances

Grinding machines are specialized devices. Before purchasing, you need to thoroughly familiarize yourself with its classification and type, and find out how much it costs. This will allow you to determine which sander model is best to buy.

In addition, in order to choose a grinding machine specifically for your needs, it is recommended that before purchasing you familiarize yourself with the criteria for its selection, and also consider the presence of various additional functions in this electrical device. When choosing a particular model, it is recommended to pay attention to its demand among buyers. The editors of the YaNashla website have prepared for you a rating of high-quality, best grinding machines as of 2021.

Using a sander

Matting the surface of a car body is done with a special tool - a plane or a grinding machine. There are many options for the latest devices, but the eccentric or orbital sander is considered universal. The scope of its application is extremely wide:

• cleaning the car surface from the old layer of varnish and paint;
• processing of transition zones before local painting of certain areas;
• leveling areas after applying filler (putty).

For grinding large and flat surfaces with high rigidity, it is advisable to use a surface grinder.

It is unacceptable to use surface grinding equipment on curved, curved and thin-walled surfaces, this can lead to deformation of the parts!

For problem areas of the car that need sanding, it is better to use a plane.

Performing grinding with an orbital machine has a high-quality result if the following rules are observed:

1. it is necessary to regularly check the serviceability of the components: dust removal hose and vacuum pump;
2. while matting, the sole of the machine must be tapped periodically so that abrasive particles do not get clogged inside;
3. There is no need to put pressure on the grinder; grinding occurs under the own weight of the device itself;
4. The heating of the surface of the car body must be controlled, and if necessary, technological breaks must be arranged.

Compliance with these simple points will allow you to perform grinding efficiently and quickly.

Choosing the best grinder in 2021

How to choose a grinder, which brand of tool is better, what to look for and what mistakes to avoid when choosing such a device? There are many different factors to consider when choosing a sander. As previously described, first of all it is necessary to pay attention to its power indicators, as well as its dimensions - these are one of the most important criteria for choosing such a machine. However, taking into account the recommendations of experts, we should not forget about the presence of all sorts of additional functions that popular models can be equipped with. It is also recommended to pay attention to the country of origin.

For example, the presence of an additional handle allows you to reduce the vibrations emanating from the device, which significantly simplifies the process of doing the work.

The dust collector (which is presented in the form of a special container) collects dust and various debris generated during operation of the machine.

Models equipped with a battery are classified as mobile tools. They can be used in areas where there is no connection to the electrical network, for example, in a summer cottage. Devices that are equipped with a speed stabilization system and a starting current limiter do not allow the disk to slow down under heavy load, which significantly improves the quality of surface treatment.

Engraver Dremel 3000-2/25

The Dremel engraver is a versatile, multifunctional device that can do the work of a sander and router. In addition, thanks to the use of this device, it is possible to engrave on the surface being processed. This device is equipped with a motor whose power is 130 W.

The Dremel engraver can be used to clean up surfaces or seams. This device is also perfect for cars and for working on metal surfaces. With its help you can engrave them. The start and speed control buttons are conveniently located on the surface of the device body, which greatly simplifies the process of doing work. The maximum speed of the device is 33,000 per minute.

Engraver Dremel 3000-2/25

Advantages:

• Ergonomic handle that does not slip in the hand;
• Ability to use a variety of attachments;
• Is a multifunctional tool;
• Light weight (550 grams);
• The device comes with a special storage case.

Flaws:

• The engine power may not be enough to perform complex work;
• Cost (5,930 rubles).

Wortex CAG 1812 angle grinder

The Wortex CAG 1812 angle grinder has a wide range of applications. It can be used for a variety of jobs, both as an angle grinder and as a tool for cutting materials. Equipped with a replaceable handle that can be mounted on the left or right side. Thanks to this, the criteria for convenience when using this tool are significantly increased. This device does not operate from the mains, but from a removable battery. Thanks to this, the Wortex CAG 1812 angle grinder is a mobile device that can be used in areas where there is no possibility of connecting to the electrical network. The maximum disc diameter that can be used in this angle grinder is 125 mm.

Wortex CAG 1812 angle grinder

Advantages:

• Battery operated;
• A large number of revolutions (8,000 revolutions per minute);
• Light weight (1.6 kg);
• Low cost (3,467 rubles).

Flaws:

• Over time, the battery capacity decreases and, therefore, it will need to be replaced;
• The engine may not have enough power to perform heavy, complex work.

Angle grinder Interskol angle grinder – 150/1300

Equipped with a powerful 1.3 kW electric motor. Thanks to the high power of the electric motor, at maximum speed (8,500 rpm), this power tool can be used for a long time. The Interskol angle grinder - 150/1300 is equipped with a replaceable handle that can be installed in three different positions. The maximum diameter of the disk used is 150 mm. This device operates on mains power and is equipped with a power button lock.

Angle grinder Interskol angle grinder – 150/1300

Advantages:

• Low cost (3,030 rubles);
• A large number of revolutions;
• Equipped with a high power engine;
• Can be used for extended periods of time to perform complex work.

Flaws:

• Heavy weight (2.5 kg);
• Due to the large dimensions of the device, it is not always convenient to process surfaces that are located in hard-to-reach places.

Belt sander Mekkan MK82605

It is, according to buyers, one of the best professional tools with high build quality. Not suitable for sanding large surfaces. The Mekkan MK82605 belt sander can be used for additional grinding of large parts in production. It also does a great job of sanding small, fine parts. The tape size of this device is 533x75 mm.

The design of the Mekkan MK82605 belt sander does not allow it to be used for prolonged surface grinding work. This is due to the fact that its body is made of plastic.

Belt sander Mekkan MK82605

Advantages:

• Availability of an additional handle;
• Equipped with adjustable belt rotation speed;
• Equipped with a power switch;
• The device comes with a dust collector;
• Low cost for instruments of this type (average price is 3,500 rubles);
• The power of the device is 1010 W.

Flaws:

• Suitable for small jobs only.

Eccentric sander VIHR ESHM – 125E

The textured body makes it easy to use. When carrying out surface treatment, the level of vibrations emitted by the eccentric sander VIHR ESHM - 125E is minimized. This power tool is well balanced, which reduces the level of stress on your hands during operation.

On the eccentric sander VIHR ESHM - 125E, the on/off button is reliably insulated from dust. Thanks to this, the service life of the device is significantly increased. The number of disk revolutions is 14,000 rpm. The sheet is attached to the surface using Velcro.

Eccentric sander VIHR ESHM – 125E

Advantages:

• Inexpensive (average price is 2,320 rubles);
• The device comes with a special dust collector;
• Equipped with adjustable disk rotation speed;
• Equipped with an additional handle and a lock against accidental activation.

Flaws:

• Low device power (450 W);
• The maximum disc diameter is 125 mm (it is difficult to process large surfaces).

Straight grinder Makita GD0600

From one of the best manufacturers of power tools, Makita, the GD0600 model is a powerful tool that is excellent for grouting joints on both pipes and sheet metal. The maximum number of revolutions of this device is 25,000 per minute. This machine is lightweight, so it is perfect for delicate work involving surface sanding. The Makita GD0600 weighs only 1.6 kg.

Straight grinder Makita GD0600

Advantages:

• Availability of a locking button to prevent accidental activation;
• Relatively low cost for a tool of this class (5,085 rubles);
• Equipped with a collet (6 mm).

Flaws:

• Electric motor power (400 W);
• Creates a lot of noise during operation.

Using a hand tool - a plane

A plane is considered a hand tool for matting a car body. A fine-grained piece of sandpaper is attached to the device and the craftsman begins to make smoothing movements over the surface in any order. The more varied the motion trajectory, the higher the quality of grinding.

When working on a car body by hand, it is generally recommended to use sandpaper or Scotch-Brite. In this way, areas with complex terrain are matted; movements should also not be of the same type.

Car grinding machine

Today, a modern manufacturer is ready to offer the buyer the following types of machines:

• Tape - a distinctive feature is that with their help it is possible to process large surface areas of the car. The working body in such a machine is an abrasive belt, due to the translational movement of which the working surface is polished. Its movement is reminiscent of how the tracks on a tractor work. Additionally, the kit includes a dust collector that prevents abrasive particles from entering the air during operation of the belt.
• Vibrating or polishing - polish the surface using a rectangular sole on which the abrasive is fixed. The abrasive is secured either with Velcro or with a clamping mechanism. The grinding process is carried out in a reciprocating motion.
• Delta grinding - the only difference from the previous ones is that the sole itself is made in the shape of a triangle. It moves either in orbit or around its axis. Used for polishing hard-to-reach areas.
• Eccentric - have a round base on which a grinding wheel is attached. The work is carried out by simultaneous rotation of the tool sole in orbit and around its axis. This technique significantly speeds up the work process.
• Angular - in such machines the working element is a grinding wheel rotating around its axis. A close brother of this unit is the ordinary “grinder”.

Sanding with water

Sanding a car using the “wet” method means constantly wetting the body with water. A damp sponge is used for these purposes. The water needs to be changed frequently to avoid excessive contamination. After sanding with water, the body surface should be washed and wiped dry with a lint-free cloth.

Polyester putty coatings can only be sanded dry, because the filler is very hygroscopic.

If there are smudges or light shagreen marks on the car body, sanding will be much more effective by adding a few drops of liquid soap to the water.

Orbital sander market overview

Any body repair is focused on creating a perfectly smooth new paintwork on the car. A grinding machine will help you mechanize your work in preparing the work area. The operating principle of the orbital device is to combine the rotation of the sole and the displacement of the orbit due to the eccentric by a diameter of 2 to 6 mm. The complex effect on the car body allows you to achieve a high abrasive result.

The basic configuration of any grinder includes either an electric drive or an air drive from a compressor. Many craftsmen prefer the first option, because pneumatic equipment requires a large volume of air and a powerful compressor. The volume of the compressor is impressive, as is the energy consumption it consumes.

Pneumatic orbital sanders are a popular product among auto repair shops; for home use, an electrically driven device is sufficient.

Orbital grinding technology is selected according to the following parameters:

1. power consumption of electricity (200-600 W);
2. rotation speed indicators (revolutions per minute);
3. rhythmic vibration of the sole;
4. the presence of a function for regulating the eccentric stroke in mm;
5. diameter of the working sole (12.5 or 15 cm);
6. are there holes on the sole for dust removal;
7. weight of the device (1-2.5 kg).

The basic equipment of the sander contains a 6-sided wrench, with which the sole is installed and removed. There is also a dust container, and sometimes a spare handle. Many models are equipped with a function for connecting to a vacuum cleaner.

To polish a car body, in addition to the orbital machine, the master will need consumables for it, namely abrasive wheels.

Orbital grinding equipment costs differently, depending on the popularity of the manufacturer’s brand. So, for example, a Rupes SL 42 AE plane (Italy) can be bought for 26 thousand rubles. Less famous manufacturers offer more modest prices. For example, a JAS-6531 pneumatic polishing machine from Jonnesway (Taiwan) costs 9.7 thousand rubles.

How to choose a grinder

Power

In the case of choosing the power of the machine, everything is simple: the higher it is, the more efficiently the device will work with pressure on the surface.
You should not single out the input and output power of the device as the main selection criterion. Many manufacturers like to artificially increase the power of the device, but it may not be important if the other characteristics of the sander are rather weak. At this point, the choice depends on your budget, as well as your needs. If you are going to work with a sander often and you need to process large surface areas, then choose a more powerful device. For domestic needs, there is no point in chasing watts; a device with a power of up to 1000 W will be sufficient.

The size of the attachments on the device also depends on the power. The higher the power, the larger the working surface that can be installed on it.

Speed

Each sander has a speed setting. It shows at what speed the spindle of the device rotates (if it is an angular or eccentric machine) or indicates the speed of the belt (for tape devices).

Speed ​​is directly related to the power of the device. If the power of the grinder is insufficient, then pressing hard on the tool will only reduce it, as will the efficiency of grinding in general. Good manufacturers can balance speed and power (with an average person's pressing force in mind).

Belt devices are characterized by a belt speed of 250 to 500 meters per minute. Keep in mind that in powerful devices at high speeds you can damage the surface if you press too hard on the machine and leave it in one place.

For tools with a rotating working part (angular and eccentric grinders), conscientious manufacturers indicate both the rotation speed at idle and when working with surfaces. The latter figure is always lower due to pressure and increased friction. It is customary to grind hard materials at high speeds, while soft materials require a more gentle approach; polishing is also best done at low speeds.

It is better if the device is equipped with a speed control system.

Oscillation frequency and eccentricity

This parameter applies to vibration and eccentric sanders.

The armature rotating inside the device is specially shifted away from the center of gravity of the device, which causes it to vibrate at high speed. The grinding process occurs due to vibrations. The higher the oscillation frequency of the device, the more efficiently it will perform its task. The downside is that due to the higher range of motion, the processing will be somewhat rougher.

The concept of eccentricity shows us how large the radius of the conditional circle along which the sander blade moves will be. More is more effective, but again, rougher. For machines with a large number of eccentricities and a high vibration frequency, it is often recommended that after initial surface treatment, change the abrasive to a finer one and go over the material again.

Dimensions

The greater the length, width and diagonal of the working surface, the more productive the device. If you are going to work with large areas, choose a larger device, but do not forget about the power. The tool should freely “pull” the required tape or abrasive wheel.

Batteries or network

Grinders can operate either from a standard electrical outlet or from batteries. There are also combined devices.

Just keep in mind that battery-powered models are very mobile, but they will have to be charged. And with mains-powered devices, you will have to carry an extension cord with you.