Tag - Comprehensive interpretation of hand sanding in painting

Comprehensive interpretation of hand sanding in painting

Comprehensive interpretation of hand sanding in painting

To a great extent, the beauty of furniture surface depends on sanding and finishing. As the saying goes, “very painted, three parts of sand”, we can see the importance of sanding in painting. Generally speaking, sanding has the following functions in coating operation:

  1. In the blank processing process

Remove burr, oil stain and other surface pollutants on the surface of blank, and provide clean and active coating surface.

Reduce the surface roughness of the workpiece, and remove all kinds of machining traces left on the surface during mechanical or manual machining

  1. In the sanding process of primer

Enhance the smoothness of coating surface and reduce the consumption of paint.

Enhance the roughness of the coating surface and enhance the adhesion of the paint.

  1. In the finishing sanding process

Remove dust particles from the coated surface.

Enhance the roughness of the coating surface and enhance the adhesion of the paint.

  1. In polishing process

For polishing workpiece, sanding is also conducive to smooth polishing.

Sanding method and its advantages and disadvantages

There are two methods of sanding, i.e. artificial sanding and mechanized sanding. There are three kinds of manual sanding: dry sanding, wet sanding and manual mechanical sanding.

Dry sand

Generally, it is suitable for dry, hard and brittle finishing surface, which will produce a lot of dust in the process of operation and affect the environmental health. The advantage of manual sanding is that any part can be constructed, and the disadvantage is low efficiency.

Precautions for manual sanding

  1. Reasonably select sand paper of different thickness, not too thick, not too many with one model;
  2. Do not skip sand (refer to the type of sandpaper), from 200 × to 600 × or 800 ×.

Manual sanding technique and skill

  1. Sanding shall be conducted along the wood grain without random grinding, otherwise the wood grain will crack and the painted furniture will leave permanent defects.
  2. The corners and edges of sanding objects shall not be collapsed, and the action shall be light, and the original round or square outline shall be maintained. The decorative line must be kept straight, and it cannot be bent, broken or deformed.
  3. When sanding, generally press and hold with four fingers and palm, and clamp the sandpaper with thumb. Furniture with large sanding area can be sanded along the grain of square wood.
  4. When grinding and brushing, as the sand grains of the sandpaper are easy to fall off, it is possible to break the wood grain after rubbing the surface.

II. Wet sand:

Generally, it is only used for hand sand. Dip water into sandpaper and polish. Wet sand can reduce sand marks, improve the smoothness of coating, save sandpaper and labor, and there is no dust drift, which will not cause environmental pollution. However, the workpiece with water sand can only be coated after the water grinding layer is completely dry, otherwise, the paint film will be whitened or peeled off. In addition, it has strong hygroscopicity

III. manual mechanical sanding

Large area construction with electric or pneumatic sander is helpful to improve work efficiency.

Because manual sanding is heavy and continuous, and the efficiency of sanding equipment is poor, the pollution is serious. Therefore, it is an inevitable trend to use mechanical sanding to deal with furniture. The efficiency and uniformity of mechanical sanding are not achieved by artificial sanding.

The quality of sanding will directly affect the aesthetic effect of furniture painting. The above is the in-depth interpretation of sanding related knowledge brought to you in this issue. Please continue to pay attention to more highlights