Grinder disc for wood – pros and cons

What a “grinder” is nowadays, even a schoolchild knows, is an angle grinder designed for working with metal workpieces using special cutting and grinding wheels. Not everyone, but only professionals, know that such an electric tool can be used for processing wood, so this article is intended to fill this gap in the information available to ordinary users. Disc for an angle grinder for wood - types, general characteristics and standard sizes, as well as safety measures for use and a review of prices for popular models - this is the topic of this article by the editors of HomeMyHome.ru

Depending on the type of discs used, the “grinder” in skillful hands can be used at various stages of working with wooden workpieces: from sawing to grinding

Is the angle grinder designed for working with wood?

The “grinder” was not originally intended for sawing wood, especially for workpieces of considerable thickness and hardwood. This is due to the design features of this type of tool and the associated dangers of use:

• when the saw blade jams, it is difficult to hold the angle grinder in your hands, which can lead to injury;

Important! Jamming of the saw blade when using an angle grinder to cut wooden workpieces is the most common problem with this type of work, which is due to the softness and viscosity of the wood.

• Inhomogeneity of the wood structure due to the presence of knots can lead to damage to the saw blade being used and injury to the user.

Using special circles and following safety rules, the likelihood of injury can be reduced to zero, even when sawing lumber products.
Despite the potential danger of using angle grinders as a tool for sawing wooden products, manufacturers of consumables, which include grinder discs, produce similar products .

Expert's point of view

Victor Isakin

Tool selection specialist for the 220 Volt retail chain

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“For processing workpieces of considerable thickness and for professional use, it is most correct to use a tool originally intended for sawing wood, such as a circular saw and a circular saw.”

The main and most common uses of grinders when working with wood are: stripping, grinding and polishing, for which manufacturers produce special types of discs.

How to choose a grinder to create a circular saw

Any professional equipment can be used. However, it is worth noting that the more powerful the grinder, the more productive the sawing unit will be. If you use angle grinders with low power, then the future structure will only be able to work with chipboard and any thin sheets.

The only thing that is important to pay attention to is the characteristics of the short-term operation of the unit. If the design becomes hot, the engine will soon become unusable.

If there is a need to systematically use the structure, you need to purchase an angle grinder of suitable power (at least 1600 W).

General characteristics of discs for grinders, depending on the type

Discs designed for different types of use vary in their design and the materials used in their manufacture. In this regard, different types of similar products have different general characteristics, which requires their separate consideration.

Circular disc for angle grinders for wood, 125 mm

Cut-off models

There are several types in this product category:

• circular saw blades – considered “dangerous” saw blades;
• chain - made using links intended for chain saws;
• with a small number of teeth - they are the safest compared to compass analogues;
• made of tungsten carbide - the safest type of such equipment.

The chain disk can be used for both sawing and roughing

For your information! Circular discs come in two modifications: a “dangerous” and a “less dangerous” option. A distinctive feature of models of the “less dangerous” type is the presence of protection against jamming, provided by the spread of the teeth.

Chain modifications are less dangerous when used, because Their design provides for a non-fixed fit of the saw chain on the surface of the disc.

Expert's point of view

Victor Isakin

Tool selection specialist for the 220 Volt retail chain

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“If the saw chain jams during use, the disk mounted on the angle grinder continues to rotate, the tool does not break out of the hands, allowing it to be stopped in an emergency.”

A disc with a small number of teeth cuts wood well both along and across the grain

Discs with a small number of teeth come in two types:

• with 3 teeth – used with small “grinders” with a diameter of up to 150 mm;
• with 4 teeth - used on large grinders with a diameter of 230 mm.

A distinctive feature of models made from tungsten carbide is the absence of teeth on the cutting surface of the product. The cutting element is the segments located around the circumference of the disk.

Important! Tungsten carbide models are capable of sawing various metal products (nails, screws, etc.) that may end up in the workpiece without damaging the cutting elements or their integrity.

Appearance of a tungsten carbide disc mounted on an angle grinder

Discs for roughing work

For stripping wooden products, manufacturers produce several types of attachments that differ in design and types of materials used in their manufacture.

A grinding disc with crumbs applied to its surface

By design, such nozzles can be made in the form of:

• a disk with spikes or crumbs applied to its surface;
• glasses with cutting elements made of twisted wire inserted around its circumference;
• disk with wire turns mounted on its surface.

Expert's point of view

Dmitry Kholodok

Technical director of repair and construction

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“Sanding attachments are used to remove paint and other coatings applied to a wood surface, as well as to rough the wood surface being leveled.”

Attachments for the “grinder”, which have twisted wire elements in their design

Grinding and polishing models

To perform grinding and polishing, there are special attachments used for both wood and other materials (metal, plastic, glass, etc.).

Set of polishing attachments for angle grinders (125mm) Bison model “3591-125-H7”

Nozzles used for such purposes are of two types:

• the basis of the design is a metal base fixed to the angle grinder shaft, and circles made from sandpaper of different grain sizes or polishing materials (felt, fabric, etc.), which, in turn, are attached to the base using Velcro;
• flap sanding wheel.

Flap sanding wheels are available in different grits, which allows you to choose the one you need for a specific type of processing.

Technique for sanding wood with an angle grinder

When starting to process wood with an angle grinder, you need to keep two main points in mind:

• You should not process the surface of the workpiece with the entire area of ​​the grinding disc, as marks from the wheel may remain. Only the upper part of the nozzle is used.
• During sanding, the grinder is guided along the grain of the wood: this way there will be no marks left. At the same time, it is important to find a support point so that your hands do not get tired.

The general process of sanding wooden surfaces with a grinder is divided into several separate stages:

1. Preliminary preparation of the coating. All remnants of the previous paint and varnish are removed with rough grinding wheels. It is also worth making sure that there are no nails or screws sticking out from the floor or wall, if they are the ones being sanded. Protruding fasteners must be removed, and if this is not possible, immersed as deeply as possible into the surface so that they do not in any way affect the operation of the angle grinder.

Pre-processing of the part
When sanding floors, there are two more mandatory rules. Even if only a small area of ​​the floor is being processed with a grinder, it is recommended to remove all furniture from the room and cover doorways and windows with thick film or oilcloth to protect from dust. Any cracks or gaps in the working surface are unacceptable. Only after filling the holes with a special wood putty and drying can you start sanding.

1. Primary grinding. It is carried out with coarse-grained discs in the range P20-P40. If you don’t have such a circle at hand, you can cut out and glue a piece of sandpaper to the angle grinder attachment. Perform 2-3 passes with a grinder over the entire working area. At this stage, it is especially important to control the force of pressing on the nozzle: weakly - the processing will not be good enough, too much - a large load on the angle grinder motor.

Primary grinding

1. Fine stripping. Replaceable petal attachments of varying degrees of granularity are used - from P60 to P80. The master makes 1-2 full passes over the wooden workpiece being processed.

Fine grinding is done using a flap attachment.

1. Putty gaps. After sanding, all gaps must be eliminated. First, they are passed over with a nozzle with a minimum grain size, and then the treated areas are puttied. Two points are worth highlighting here. In places that are difficult to access, you will have to process them manually. Plus, during grinding a lot of dust is generated, and we must not forget to remove it in a timely manner.

Wood putty

Final grinding steps

Final polishing of the wooden surface is carried out using sanding discs made of felt and soft cloth marked P100 or P120. A wax-based polishing paste is first applied to the wood, and then 1-2 passes are made along the surface area to be treated. After polishing, all that remains is to prime the surface. By priming, not only the remaining small roughnesses are smoothed out, but the service life of the wood is also extended. Oil paints or alkyd enamels are best suited as a primer for wood.

The procedure is done manually with brushes in the following sequence:

1. Dip the brush well in the primer, apply to the workpiece, spread over the entire area.
2. Wait until the paint is completely absorbed and the wood dries - at least 2 days.
3. Apply 2 more layers of primer, and the second can be coated only after the first has dried.
4. After this, the priming will be completed. You can apply a top coat of varnish to the wood.

Priming wood

Standard wheel sizes for grinders

When producing discs for angle grinders, the company's manufacturers operating in our country produce their products in accordance with the following regulatory documents:

• GOST 21963-2002 (ISO 603-15-99, ISO 603-16-99) “Cutting wheels. Technical conditions".
• GOST R 53410-2009 (ISO 603-12:1999-ISO 603-14:1999, ISO 15635:2001, ISO 13942:2000) “Grinding wheels for hand-held grinding machines. Technical conditions".

In accordance with these documents, the standard sizes of disks used on angle grinders are: 115, 125, 150, 180 and 230 mm.

For your information! The seat size for all standard sizes is 22.2 mm.

The use of angle grinders for grinding wooden products is quite widespread among users of different categories.

How to make a key for connecting a circular machine

To produce a key, you need to disassemble the frame of the angle grinder to find the wiring. They must be attached to the switch located at the finished base.

You can try an easier method: drag the start key with a zip tie. In this situation, the device must be connected to the network to start operations.

woodworking

On the domestic market of hand-held electric tools, discs for angle grinders from Russian and foreign companies are presented. Among them, the most popular are:

• "GRAFF" (Belarus);
• "GREATFLEX" (China);
• "Bosch" and "Klingspor" (Germany);
• “Ziflex”, “PRACTIKA”, “LUGA” and “ZUBR” (Russia);
• "Makita" and "Hitachi" (Japan);
• "FIT" (Canada).

In addition to the brands listed above, other manufacturing companies are also popular in different regions of our country, which is due to the location of the region and the presence of dealers of these companies in a particular territory.

Saw blade brand “Zubr” with outer diameter 235 mm

We cut wood with a grinder

You can cut wood with a grinder in a relatively safe way. It provides for rigid mounting of cutting equipment on a frame with guide elements. This will be stationary equipment for sawing, in which the grinder is securely fixed. A self-made machine works on the principle of circular saws, where the material being processed is fed along guides.

You can cut firewood with a grinder, but you must use the devices necessary to ensure safety. More suitable for working with wood are a jigsaw, circular saw, and hand tools.

Safety precautions when working with a grinder on wood

When performing work on wood processing using an angle grinder, the safety measures are the same as when using metal and other materials. However, in connection with the physical properties of wood, which have already been written about above (softness and viscosity), it is necessary to take them into account, and in this regard:

1. You cannot fix the “Start” button, because in this case, it will not be possible to quickly turn off the tool.
2. Sawing workpieces must be performed at a strictly specified angle, without creating distortions that can cause the saw blade to jam.
3. All work must be carried out with the protective cover installed and the use of personal protective equipment (gloves).

   
   When performing grinding work, the use of respiratory protection is also necessary.

4. It is better not to use “dangerous” saw blades equipped with large teeth on large-sized “grinders”, because In the event of an emergency, it will be impossible to hold the tool in your hands.
5. The presence of a speed controller on the tool is not a prerequisite for its use for such work, but it is desirable, because This will reduce the likelihood of injury if the saw blade jams.

Precautionary measures

The master in the photo did everything right - he put on gloves, goggles, a respirator and clothes with sleeves.

When processing wood with hand tools, it is important to follow safety precautions and precautions. This is especially true for grinders, because the rotation speed of the circle reaches 13,000 rpm.

There is no such thing as too much protection.

It is imperative to protect your eyes, hands and respiratory tract, for which the following means are used:

• Construction safety glasses or masks;
• Work gloves made of fabric or canvas;
• Respirators or gauze bandages;
• Long sleeve robe;
• Various protective covers for tools, suction and removal systems for chips and dust.

High-quality models of sanders are equipped with vacuum cleaners to remove sawdust.

Important! When working with an angle grinder using rigid attachments, the operator must be in an area that does not intersect with the plane of the scattering of fragments when the wheel is spaced apart during rotation.

Review of prices for popular models

The cost of products depends on the place of their sale, technical characteristics and brand of the manufacturer. This section of the article presents several models, on the basis of which one can get an idea of ​​the order of the numbers that determine the cost of one or another type of similar product.

"GRAFF Speedcutter"

The “GRAFF Speedcutter” disc is a model with a small number of teeth.
The disc is designed for sawing wood and plywood, laminate and board materials (fibreboard, chipboard). The model is equipped with three teeth.

Review of the “GRAFF Speedcutter” model:

More details on Otzovik: https://otzovik.com/review_6165824.html

GRAFF Speedcutter

"GREATFLEX 71-125120"

This petal-type model is made on a fabric basis using abrasive materials
GREATFLEX 71-125120 and consists of 72 petals located at an angle of 10˚ to the working plane of the disk, which allows to increase the efficiency of use of the product.

Review of the GREATFLEX 71-125120 model:

More details on Otzovik: https://otzovik.com/review_4655934.html

GREATFLEX 71-125120

"Bosch 2608623013"

“Bosch 2608623013” can cut wood and nails, plastic and drywall.
This model is coated with hard metal alloys and is universal in its use.

Review of the Bosch 2608623013 model:

More details on Otzovik: https://otzovik.com/review_3959218.html

Bosch 2608623013

"PRACTICE 773-606"

Appearance of “PRACTICA 773-606”

PRACTICE 773-606

"FITIT 39556"

The FITIT 39556 model is successfully used for grinding materials of varying degrees of hardness

The cost of “FIT IT 39556” ranges from 95 to 130 rubles, depending on the company selling the product.

FIT IT 39556

"Luga 3656-125-25"

Appearance "Luga 3656-125-25"
One of the most widespread models among ordinary users. It is characterized by low cost and good performance characteristics.

Review of the Luga 3656-125-25 model:

More details on Otzovik: https://otzovik.com/review_3749759.html

Luga 3656-125-25

Cutting wheel

Due to the fact that this tool has high speeds and cannot be firmly fixed in the hands, high-strength tungsten carbide is used for such circles, which is why their price is respectable.

A cutting disc for wood for a 125 mm grinder is classified not only by diameter and, accordingly, depth of cut, but also by shape, frequency and number of teeth.

Disc with goiter from a chainsaw.

• If you plan to use a saw blade for wood for a 125 mm grinder periodically, and you don’t know what kind of wood, you will need to cut. The best option would be a circle with variably beveled teeth.
• For cutting softwood, as well as any other soft wood, you can use products with straight teeth.
• The trapezoid tooth has a wider range of uses. Wood saw blade for grinder 125x22.2 mm with trapezoidal teeth, capable of cutting medium-density wood chips. It is also easy to use on laminated particleboards, USB boards and medium-density fibreboards.

Circle with beveled tooth.

As you know, an angle grinder operates at high speeds, so the wheels can get very hot. The use of water cooling in this case is impossible.

In order to avoid overheating and deformation of the metal, rounded slots up to 2 mm wide and up to 20 mm deep are made from the teeth towards the shaft. They can be empty or filled with copper. This measure compensates for the expansion of the metal and prevents its deformation.

Grinding and roughing work

If cutting wood is considered a very traumatic activity, then grinding solid wood does not require great qualifications. Here, flap discs are often used to sand wood with a grinder.

Petal disc.

The structure of such a circle is reflected in its very name. Many sandpaper petals are attached to the work surface in several layers like fish scales. When rotated, the paper gently sands the wood. The quality and level of processing of the board directly depends on the grain size of the material.

The flap wheel, although very common, is not the only option for surface grinding. Relatively recently, so-called universal sticky discs have appeared on the market. The advantage of such attachments is that they can be changed without removing the disk.

Disc for soft grinding.

The base is equipped with Velcro; as a result, the working surface itself with the desired grain is simply glued on top of the circle. The price of such Velcro is significantly lower than that of a solid petal disk, but they also wear out much faster. Another advantage of this design is their versatility. Velcro is produced not only for wood processing, but also for grinding stone or metal.

Important: no matter what type of tool you use, the surface of the wood itself must be well dried and preferably without cracks. It is not recommended to sand wet wood, and the surface infected with fungus should first be cleaned using a sanding attachment.

Quite often, when preparing a surface for application of any coating, it is necessary to remove a layer of old paint or varnish. Working with a plane is not possible in every case, and the sanding flap disc quickly becomes clogged with paint dust.

Peeling attachments.

In this case, stripping attachments are well suited; such a tool is especially effective for processing repeatedly painted old surfaces, for example, when cleaning a wooden floor.

Such attachments are a metal circle with metal wire bristles inserted into it. The wire can be positioned either around the perimeter of the circle, parallel to the disk, or perpendicular to the surface according to the brush principle.

Standard grinder.

The video in this article shows how you can make a disk for cutting wood with your own hands.

Sawing with a grinder

If there is no other way out, that is, there is no special saw for wood (it’s broken) or urgent small work is required, of course, a grinder can help out. However, we must remember that the main purpose of this machine is not to cut wood. To use an angle grinder as a hand-held circular saw, you will need to stock up on one or more specialized attachments.

To avoid distortions and jamming, you need to saw in a comfortable position and fix the tool with both hands. The best results can be obtained if you do not remove the special guide handle; with its help it is much easier to control the angle grinder. Correctly sawing off a workpiece using a grinder is not at all easy; due to the heterogeneity of the wood, the operating mode will constantly change. Therefore, while working, it is better not to be distracted and monitor how the cut is progressing.

Grinding discs

Grinding wheels for grinders have a working plane of different types. This is determined by the characteristics of the material to be processed and the required quality of the resulting workpieces. Such equipment is divided into types:

• sponge-type discs or fabric version - used in conjunction with special pastes or liquid substances for grinding and polishing;
• solid circles of felt origin or with a plastic base - they have transversely located petals, used in conjunction with pastes for polishing work;
• discs with replaceable sandpaper - differ in thickness, are finely abrasive, and can be used in the process of grinding or pre-cleaning.

To sand a large work area, sand logs or rounded areas, use cone-shaped equipment.