The intermediate primer prepares a well-lubricated working surface for the topcoat, completes the last process of all primer work, increases the adhesion of the participating layers, and has a certain isolation effect to ensure the quality of the topcoat is not chaotic.
Paint surface treatment is the last process of topcoat. When the paint surface is dry and firm, the defects on it will be dealt with. If you do your best, it will flow to the center of a department that is not very satisfied. Then, as long as it is repaired in the later stage, stop polishing and cutting with coarse wax composed of pumice or clay, and get rid of the traces of sandpaper.
Extended data:
material requirements
In automobile manufacturing and maintenance, the shapes of many sheet metal structures are very complicated. In order to avoid the difficulty of sheet metal, sheet metal materials must have good technological performance requirements, namely:
Sheet metal materials must have good plasticity. Must have the ability to produce permanent deformation under the action of external force without being destroyed. For cold-worked parts, good cold plasticity is required, such as stamping parts of automobile parts; For hot working parts, good thermoplasticity is required, such as hot forgings, spring steel plates, hot rivets, etc.
Good weldability. Many automobile sheet metal parts are welded together by spot welding, oxygen welding, arc welding or gas shielded welding, so it is required that the sheet metal parts must have good welding performance. This is especially important in automobile maintenance and repair. Materials with good weldability have high welding strength and low cracking tendency.