Often in everyday life there are situations when a particular surface needs to be sanded, remove the old coating of varnish or paint. Manually dealing with this is very difficult, especially with a large amount of work. Therefore, an electric grinder is a necessary tool in the arsenal of any home master. Depending on the correctly selected equipment and consumables, it is possible to successfully solve a wide variety of tasks for processing various surfaces.
Principle of operation
This type of grinder is called so because the skin of the skin is attached to the tool rollers, which looks like a closed tape. When the rollers rotate, the web moves continuously. As a result of this movement, various surfaces are quickly and efficiently sanded. It is advisable to use a belt sander for processing large areas, since it has high productivity. Modern mechanisms have an adjustment of the speed of the tape.
How to choose the right one?
A sanding belt is a fabric or paper base on which abrasive grain is fixed with glue. It sticks together in a ring, so it is often called endless. To make the perfect choice, you need to carefully study the types of sandpaper bases, the properties of abrasive materials, have an understanding of the length and width indicators of sanding belts, and also know what grain size is.
Types of sandpaper basics
An emery tape for the grinder is the most demanded abrasive. People call it a skin, since shark skins used to be used for grinding. It, like the tape, has its own basis. It is worthwhile to familiarize yourself with the most common skin skins in more detail.
- Paper. This is the most common and economical type of base. Such paper is impregnated with polymers to give it strength and resistance to abrasion or tearing. But for intensive use, it is not recommended.
- The cloth. This is an elastic base that easily takes the form of a product. It is more stable, it has a long service life, but the abrasive may crumble under tension. The fabric base of the skin is durable and resistant to moisture. It is used for intensive work with various types of wood.
- Fiber. It is used to process solid materials.
- Combined. This is a combination of fabric and paper coated with abrasive. This base combines the beneficial properties of paper and fabric. It is resistant to bending, abrasion and moisture. Such a base has a high cost.
As you know, abrasive materials are characterized by high hardness and are used for surface treatment of various materials. Harder abrasive grains are recommended for deep processing. If abrasive grains are arranged in decreasing stiffness, the following chain will be obtained: diamond - garnet - quartz - aluminum oxide - silicon carbide - electrocorundum. The abrasive is applied to the substrate in several ways.
- Open shedding. With this method, 60% of the surface of the substrate is coated. It is recommended for soft materials with low density, prevents clogging of gaps and lumps.
- Closed Rash. It covers 100% of the surface of the base. This method is necessary when grinding metals and solid wood.
When choosing a tape, you must carefully study the parameters of its length and width. If the belt is wide, then the power of the belt sander is greater, and the speed is lower. When using a narrow tape, the power of the mechanism is low, and the rotation speed is high. The ideal choice would be the sizes of tapes of the following standard:
- width 75 (76), 100 or 115 mm;
- length - 457 or 533 mm.
Important! When choosing a width, the working conditions should be taken into account, and efficiency depends on the length.
The quality of processing of any surfaces will depend on this property. If the granularity of the abrasive material is higher, then such processing is softer. Granularity is usually denoted by the English letter R. It corresponds to a numerical interval from 12 to 2500. The larger the number, the finer the abrasive. There are several types of coarse ribbons.
- Very large. Such tapes have especially large grains (P22 – P36). They are necessary for rough grinding of surfaces and their leveling.
- Large. Tapes with indicator P40 – P60. They are required for the initial processing of the material, they are not clogged with dust due to the large grain size.
- For initial processing. Tapes marked P70 – P120 are recommended for removing paintwork or rust.
- For the final processing. Tapes with an indicator of P150 – P220. With their help, they clean the surface before polishing.
Fine-grained ribbons are also of several types.
- For finishing. They are recommended for final grinding of hardwood. Their granularity is P240 – P280.
- For polishing. These tapes make painted surfaces smooth, but can become clogged with dust and paint. Their granularity is P400 – P600.
- For fine grinding. P1000 tapes are ideal for finishing metals, ceramic surfaces or lacquered wood.
When choosing belts for a grinder, it is imperative to study the requirements of the tool and the parameters of a particular material. A high-quality sanding pad, even with frequent use, will last you a very long time.
See how to choose a sanding belt for a grinder in the next video.