10 points for the painter 3 points for the sand-the polishing of the post-processing of the prototype production process

There are three methods for the post-processing and polishing of the prototype manufacturing process: mechanical grinding, dry grinding and wet grinding.

①Mechanical polishing: In order to improve work efficiency when constructing a large area, mechanical polishing methods, such as electric polishing machines (disc type, vibration type), can be used.

②Dry sanding: sand paper for sanding. It is suitable for the polishing of hard and brittle paint. The disadvantage is that a lot of dust will be generated during the operation, which affects environmental hygiene.

 ③Wet sanding: sand paper dipped in water or soapy water for sanding. Water milling can reduce wear marks, improve the smoothness of the coating, and save sandpaper and labor. However, when spraying the lower layer of paint after the water abrasion, first, wait for the water abrasion layer to dry completely before applying the lower layer of paint, otherwise the paint layer is easy to whiten. In addition, substrates with strong water absorption are not suitable for water milling.

There is also a kind of sanding: the painting requirements are marked as "light sanding", such as sealing paint, old paint film recoating, after partial repairs, etc. At this time,finer sandpaper and skilled hands should be used to carry out "light sanding". Otherwise, it is counterproductive.

Kaiao prototype factory post-processing workshop

When using sandpaper for manual sanding, the whole piece of sandpaper is generally cut into four. After each piece is folded in half, clamp the two ends with your thumb and little finger. In addition, press the three fingers flat on the sandpaper and sand the surface of the object back and forth. According to the sanding object, it can be changed at any time, and the cavities in the fingers and the expansion and contraction of the fingers can be used to polish the concave and convex areas and corners. When sanding a large area, you need to master the principle of "higher". Use the palm to turn the sandpaper, or attach a slightly harder rubber such as a sponge or cork block. Use your thumb and forefinger to pinch the left and right end faces tightly, and place the sand flat. mill. The length of the sander's nails should be moderate to avoid hurting the fingers during operation.

The polishing process has three main functions:

①For the substrate, it is to remove the burrs, oil and dust on the surface of the substrate;

②For the surface of the putty scraped, the surface is generally rough and needs to be sanded to obtain a smoother surface, so sanding can reduce the surface roughness of the workpiece;

③Enhance the adhesion of the coating. Before spraying a new paint film, it is generally necessary to polish the old paint film after hard drying. Because the coating has poor adhesion on an excessively smooth surface, the mechanical adhesion of the coating can be enhanced after polishing.

Post-treatment-deburring       Post-treatment-spray paint

When polishing, the polishing materials should be selected strictly according to the process requirements. Generally, the sandpaper can be selected according to the following rules:

Solid wood white billet polishing selection 180#——240# sandpaper

Use 220#——240# sandpaper for polishing the plywood or the first primer

The smoothing primer chooses 320#——400# sandpaper

The last primer or topcoat should be polished with 600#——800# sandpaper

Use 1500#——2000# sandpaper for finishing paint polishing