Basic use of polishing machine

2021-09-09 16:00:22

1. The angle of the polishing disc

The relatively large inclination of the polishing machine will cause the paint surface to heat up quickly, and the friction of the edge of the polishing disc will increase, which is easy to grind the paint and also make the contact surface area of the polishing disc surface narrow. Generally, the angle of inclination between the polishing disc and the surface to be polished should be less than 30 degrees.

2. Pressure during polishing

The grinding operation is based on the uniform grinding of the paint surface. For this reason, it is necessary to find a way to "control the pressure of the polishing to a certain extent".

The pressing pressure is based on the weight of the polishing machine, and the weight of the polishing machine on the flat surface is used as the basis. Do not use too much pressure. Even if the side polishing operation is performed, the same pressure as the flat surface is required. . Do not increase or decrease the pressure, so that it is not easy to cause the aperture or scratches caused by uneven pressure to cause some parts to be thrown seriously and some parts to be lighter.

Try to avoid increasing local pressure during polishing. Excessive polishing will result in "uneven grinding surface", "polishing boundary", "polishing scars" and other reasons. Local heating will cause "polishing burn" and other reasons.

3. Grinding range

The scope of a grinding is because the shape and size of the car body are different, so it can be controlled within a certain range, with the width of the shoulder as the boundary. It will be difficult to support, and it will also cause uneven polishing surface (if the arm is used for too long and the polishing operation cannot be performed for a long time).

4. The speed of movement

The polishing machine and the abrasive on the disc surface form a relatively suitable speed during grinding. If the speed is too fast, the pressing force cannot be controlled, and the cutting amount will not be reached, and "uneven friction" will occur.

The above-mentioned processing method is the basic method, but the car’s disc surface has a complicated shape, so the following operation method is carried out: polishing is not only in one direction, but also moves in the vertical and horizontal directions (also the method of Tic-Tac-Toe), in order to avoid Avoid uneven friction.

5. The range of moving polishing-let coincide

The traces left by the polished disc surface in the paint are about 1/2 of the area that overlaps the disc surface each time.

6. Treatment of deep scratches

There are various reasons for scars on the painted surface, and the depth of the scars varies. For this reason, only sanding operations cannot eliminate deep scars, and the scars must be treated clearly. For very deep scratches, we need to use more than 2000 sandpaper for processing.

The basic principle of removing scratches:

Physical principle: relying on friction, the friction of the polishing disc itself and the friction of the abrasive particles, the coarse scratches are turned into fine scratches.

Chemical principle: There are some ingredients in the abrasive, which can fill small scratches at high temperatures.

Car polishing is actually a physical and chemical process.