How to use an angle grinder correctly: when cutting metal, at home, with a grinding wheel How to use an angle grinder correctly: when cutting metal, at home, an angle grinder is a traumatic tool with a grinding wheel. Despite this, this tool
What kind of circles are allowed?
Each type of processed material has its own abrasive tool. It is not allowed to use circles that are not suitable for the corresponding type of operation.
Under no circumstances should large discs be mounted on an angle grinder if they are not intended for this tool. Angle grinders of small sizes have high rotational speeds when compared with machines of large sizes. A large diameter circle (both new and used and reduced in diameter) may not withstand high speeds, as a result of which it breaks. This is dangerous because the protective cover must be removed to install a large diameter circle. Too much rotating load on a large diameter wheel can cause excessive bearing wear and reduce tool life.
Broken circles are not allowed. Such circles include those that have cracks, chips, gouges, deviations from flatness or roundness. This leads to a kickback and extensive damage to the circles with the formation of traumatic situations.
One of the most important safety requirements in the process of working with an angle grinder is the inadmissibility of using saw wheels in an angle grinder, which are intended for working with wood. This is due to the fact that there are a large number of tragic cases that have occurred as a result of mounting saw wheels for working with wood on an angle grinder.
Wood is a heterogeneous material in which knots can cause kickback. Nails can also be found in this material. The angle grinder has high RPM, as a result of which the saw blade can quickly become dull.
After mounting the tool, you will need to check it at idle speed for at least 1 minute at maximum speed. In the process, the wheel should rotate freely without touching the protective casing. The vibration should be the same as usual.
How to fix processed materials?
Both hands are used when working with an angle grinder.
If the weight of the part that is being processed cannot guarantee its immobility during operation, then the material will need to be securely fixed with a vice or clamps on a heavy structure. In no case should you start work holding the part in your hands. This can violate several security requirements at once:
- The angle grinder cannot be held with one hand, both hands must be used.
- The workpiece must remain stationary.
As a result of improper fastening, the workpiece will certainly begin to move, which can cause the wheel to jam with a reverse impact.
In the process of laying the workpiece, it is necessary to exclude its bending, especially if this narrows the cut. If there is a bend, then the circle can be clamped in the cut, as a result of which a reverse impact will occur. A correctly installed part should have stops at the edges and in the kerf.
Figure 1. Masks and safety goggles are used when working with an angle grinder.
During operation, sparks, abrasive particles, scales and various debris will appear that can get into the eye, which will lead to injury.
Glasses or the mask that replaces them must be covered. This is due to the fact that scales or sparks will fly along a complex trajectory, and therefore can fall behind a protective mask or goggles. It is recommended to purchase a mask that has a safety net. The blows of the fragments of the circle are so strong that an unprotected mask cannot withstand the blow. Masks and goggles can be seen in Fig. 1.
The guard is the main barrier that stands between the user of the tool and the wheel that is rotating at high speed. You should be aware that circles break quite often. Users who regularly use an angle grinder have experienced this at least once. In most cases, the destruction of the circle occurs in the process of clamping (jamming) it in the slot.
The protective cover must be installed in such a way that sparks and scale are not emitted towards the user. In fig. 2 shows how the casing can protect in case the circle breaks during rotation. The fragmentation sector will be defined by the opening in the protective casing.
Figure 2. Protecting the shroud of the angle grinder if the wheel breaks during rotation.
The casing must be fixed in such a way that the possibility of its arbitrary reversal is excluded. In some cases, it may be inconvenient to work in the casing, however, remember that in no case should it be removed. If this is done, then the person working with the tool will not be insured against negative consequences.
There are other personal protective equipment available. Gloves or mittens are also mandatory elements for protection while working with an angle grinder. Hands will be located near the rotating circle, so they should be protected from sparks, debris and other elements. It is recommended to purchase thick leather gloves to protect your hands. Cotton products will not provide reliable spark protection.
A dust mask or respirator is used only if it is planned to process stone materials without the use of dust extraction devices.
Clothes must be narrow, well-tucked in. Loose parts can be tightened in a rotating circle.
The angle grinder is excellent for roughing wood surfaces. The round nozzle grinds the surface very quickly, several times faster than a conventional grinder. This is due to the high spindle speed (10,000-12,000 rpm). But the high rotation speed has its drawbacks. This is, first of all, a large amount of noise and dust during the operation of the device. Therefore, take care of good dust extraction. When working indoors, it is highly desirable to connect a construction vacuum cleaner to the UGM. And if conditions permit, it is better to sand wood surfaces outdoors.
Another disadvantage of an angle grinder is the inability to properly adjust the rotation speed (this function is present in vibration grinders, but usually absent in grinders). For polishing, only an angle grinder with the speed control option is suitable, a variety of polishing discs cannot be put on high-speed angle grinders.
In general, the fine work of an angle grinder at high RPM is much more difficult. Especially when processing a cross-section of wood fibers, it is easy to overdo it and burn the wood (and at the same time ruin the emery cloth circle). Do not press the tool strongly against the wood, do not hold it in one place for a long time, so as not to get scorched due to overheating. And try to hold the tool firmly while working. The rotating circle with the skin (or petal disc) must be kept strictly parallel to the plane being processed. Misalignment is fraught with damage to consumables and the treated surface.
When doing large-scale activities, let the tool rest and cool down. Especially if it is a household tool. Such models are not designed for continuous operation 24/7, usually for a maximum of 8-10 minutes of continuous operation.
The subtleties of the angle grinder for wood
Different attachments are used for grinding surfaces. Most often, a circle is used, on which a round sheet of emery cloth is attached with Velcro. A flap disc with sandpaper petals attached to it is also used. It is more convenient, but the option with Velcro is reusable (with skillful handling), which is much more profitable with a large production volume (a sheet of skin is an order of magnitude cheaper than a petal attachment). For grinding painted and rusted surfaces, brush and roughing discs are used, and for sharpening the cutting edges of tools, respectively, sharpening discs.
How to properly cut metal angle grinder. Practical tips and advice
If long pipes rest on supports, the overhanging edge should be cut. If you cut them in the middle, then due to its own weight, the metal will bend and clamp the disc.
If you do not have the skills to handle an angle grinder, then before starting work, you should learn how to cut on unnecessary parts.
The cut-off wheel only accepts radial forces. Attempting to change the cutting plane while the blade is inside a metal piece will break it.
The disc heel (the near lower part of the circle) cuts metal more effectively.
In order for the angle grinder and discs to serve for a long time, you need to take a break for 20-30 minutes every 5-7 minutes of work. This rule is especially important for low-power grinders who are afraid of overheating.
To increase the service life of discs, especially expensive ones, and to cool the metal, the place of the cut should be watered. It is advisable to carry out the work together.
Aluminum is a very tough metal. When cutting a piece of large thickness, kerosene must be dripped into the seam, observing fire safety rules.
For molding, cutting of sheet metal, curly carving, you should use worn-out stub discs, so do not throw them away immediately.
The corner should be cut correctly not in one go, but separately both shelves.
If long enough pipes, corners, fittings lie on supports, cut the overhanging edge correctly. If you cut between the supports, the part will bend due to its own weight and jam the disc.
Thick parts are cut only in a straight line. If you need to cut out a curly part, straight-line cuts are first made, then the remaining unnecessary parts are removed.
Do not put pressure on the angle grinder. This will cause the blade to jam or break and overheat the angle grinder. If the cutting process is slow, the blade should be replaced.
The resulting cut should not be processed with the side of the disc. For this, a different type of disc is used.
Melted particles of metal and abrasive, falling on plastic products, glass and car headlights, get stuck in them, and then it is almost impossible to remove them. Therefore, before starting work, they must be removed or protected.
How to choose the right angle grinder
The angle grinder should fit comfortably in your hand.
The correct choice and quality of the angle grinder itself determines the quality of work and the safety of the worker.
When choosing a machine, you should focus on its main parameters: power and diameter of the cutting abrasive wheel. Its weight is also important, since it is often necessary to work by weight, and its dimensions so that it is possible to perform work in inconvenient and hard-to-reach places.
Most buyers, when they see powerful grinders, are somewhat frightened that it is more difficult to cope with it than with a low-power one. This is a misconception. Low-power grinders are more likely to jam discs, i.E. They are physically unable to pull out the disk under heavy loads. The situation how the disk and the machine itself will behave after reducing the load is unpredictable. The angle grinder will most likely tear out of your hands. The consequence of this will be a break in the disc, damage to the machine and injury to the cutter. Therefore, it is better for novice craftsmen to purchase an angle grinder for a 125 mm disc with a power of 800-1000 W and a spindle speed of 10,000 rpm. This power is sufficient for cutting iron.
For cutting metal, there are machines for a 115 mm disc powered by batteries, but, as practice shows, with their high cost in solving everyday problems, they do not justify themselves.
The handles of the angle grinder should be rubber or made of a material that will damp vibrations from the machine.
But none of the technical characteristics reflect the convenience and safety in work. The angle grinder should lie comfortably and securely in your hand so that when working with metal you focus on it, and not on how to hold the tool in your hands. It is desirable that the grips are rubber or vibration-damping material with finger recesses.
Low-powered grinders, as a rule, do not have an additional handle.
If you find any inconvenience when choosing, you should look for an angle grinder of a different model.
Basic rules for safe work when cutting metal angle grinder
The layout of the most dangerous sectors during operation of the angle grinder, taking into account the rebound and destruction of the disc.
The most necessary condition for cutting is strict adherence to the rules of safe work.
Grinder manufacturers are constantly trying to minimize the risk of injury and injury by inventing and improving various protection systems. But no one cares about the worker like he does.
The main dangers that arise when cutting metal are the flight of fragments of a broken disk, the flow of sparks and the smallest abrasive particles, the inability to hold the tool in your hands.
If the disc breaks or gets stuck, the angle grinder can be pulled out of your hands at the most inopportune moment and with great force, therefore, before starting work, you should consider the direction of its possible movement.
Safety rules cannot be neglected even when performing small work.
Before starting work, you should:
- Protect face, eyes, hands and, if possible, all body parts.
- Remove all combustible materials and objects that are in the direction of the discharge of sparks.
- Fasten the workpiece to be machined in a vice, if possible. Do not hold the workpiece with your free hand or press with your feet.
- If you are installing a new disc, you need to turn its angle grinder at maximum speed, placing it further: the disc may be defective and fly to pieces.
- Install, adjust and secure the protective cover.
It is best to protect your face with a special face shield when working with an angle grinder.
During work, you should:
- When replacing discs during rest, disconnect the angle grinder from the mains.
- To protect eyes and face, use goggles or a face shield. Professionals use both of them during extended work.
- Hold the angle grinder firmly during all work.
- To replace the drive, you need to wait until it comes to a complete stop.
- Wear protective gloves. It is undesirable to use cotton gloves, they do not provide sufficient protection, they can ignite, and the threads wind up on the spindle of an angle grinder or disc.
- During work, you need to position yourself so that the face, and, if possible, all parts of the body are not in the plane of rotation of the disk.
At the end of the work, you should:
- Wait until the disc rotation has stopped completely and only then put the tool on the floor with the disc upward so as not to damage it;
- Disconnect the angle grinder from the network;
- Make sure there is no smoke or other signs of fire.
A typical mistake that is made when cutting metal: if the diameter of the new circle is larger than the size of the protective cover, it is removed. The cover is a protection in case the disc breaks and shatters during the metal cutting process.
Instead of a disc, many put cutters, saws or other materials at hand. Doing this is strictly prohibited.