How can the basic coating process be applied to the maintenance of automobile sheet metal parts?

In fact, the basic coating process is widely used in the whole process of body sheet metal repair. The application of the basic coating process in the maintenance and replacement of the body sheet metal parts can be summarized as follows:

Basic coating of black metal sheet

The black metal plate is easy due to exposure to air or contaminated with harmful substances and other factors, gradually led to the emergence of yellow rust and oxidation corrosion, damage to the original coating layer. Especially in the process of sheet metal operation, after hammering, welding and other processes, it is more likely to damage the original coating protection layer and accelerate corrosion. Even if the paint film is sprayed, the paint film will soon fall off with the base coating. At this point, a complete coating process must be carried out again.

With a wire brush or sand paper on the surface of sheet metal for cleaning polished black. It is possible to use the nylon grinding disc, which is now widely used, to clean the metal surface thoroughly. The body for disintegration repair (especially car accident), should be in the sheet metal folding, joint spraying for removing rust and paint spraying liquid, remove the metal oxide before and after welding slag and dirt, or with good anti rust capability instead of anti rust primer.

Two. Base coating of the joint surface of sheet metal parts

If the car body is repaired, if it does not rust treatment, it will be oxidized and corroded by the presence of various impurities and water vapor within one or two years, and the strength of the welding point will be affected. Therefore, the zinc flux should be sprayed in time.

The zinc coating (zinc rich coating) is a new material used to prevent oxidation and corrosion of the joint surface of sheet metal parts. There are two forms of spray and coating. It has good conductivity, high temperature resistance and electrochemical cathodic protection. It can form a rust protection layer between the welding joints of sheet metal parts, improve the corrosion resistance of the parts around the solder joints, protect the solder joints, and ensure that the body strength after repair is not inferior to that of the original body.

Basic coating for plastic welding

Although the surface of weld, solder joint and repaired steel plate is polished and cleaned, there are countless tiny and irregular bump which is invisible to the naked eye, which contains numerous oxides, impurities, water vapor and so on. Although the ordinary putty or antirust paint has the function of antirust, it can only prevent the invasion of the appearance of rust and play a temporary sealing effect. As long as it is affected by humid and other harsh environments, defects will soon emerge. If the epoxy primer is used, it can play an effective protective role.

Epoxy primer is a good rust inhibitor when applied to the seam or lap joint surface after welding, grinding, heating, quenching and shrinking. In general is to repair the pieces of film (i.e. the feather edge film groove), after cleaning the surface coated with epoxy primer, can ensure that after processing after the panel does not rust in a very long time, even if the original rust, will prevent the expansion of the scope of rust.

Four. Base coating at the joint

Without special treatment of metal sheet metal sealing coating directly, in combination with welding or lap seam at the outer surface due to various impurities, such as erosion, vibration oil coolant, sewage and uneven pavement cracking and deformation, rust proof sealing interface defense is broken, lost function. The application of special sheet metal sealants on the spot and other parts of the plate can not be eliminated.

Sheet metal sealant is a non corrosive polyurethane PU structural adhesive, sealing, bonding and caulking, covering, sometimes also can replace welding, no damage to the paint. Its adhesive force is very strong. After curing, it has high strength and reliable sturdy. It can enhance the strength of single block and thin shell body, and can maintain the anti erosion function of welding or lap joints, especially inside and outside of the wheel arch, chassis, backup compartment, cabin floor and engine compartment.

Five, foundation coating in the chamber of the section section

During the overhaul of the car body, it will be found that the original sheet metal parts in the box section member cavity are rusty, and the steel plate is thin and penetrated before being repaired by accident repair. This is caused by the internal rust prevention, the rust exudation and the continuous expansion. The cross section members are often the main load components of the whole body, which will have an important impact on the collision and durability of the car. Therefore, the anti rust treatment must be done in the chamber of the box section or in the cavity of the bag shaped component.

The body of protective wax is cavity protection assistant, its excellent permeability, can easily penetrate into all corners and junctions, with resistance to moisture and drainage, can prevent the spray paint to prevent rust cavity wear, body sheet welding internal rust. In addition, special spray rods and nozzles can also be used for coating treatment on the internal surface of these plates. Ensure the final maintenance quality.

Other functions of body base coating

Shock resistance treatment at the combination of 1. skeleton and skin

After the cover of the engine and the cover of the luggage compartment is broken down, the body sealant must be added between the skin and the inner lining before closing. This will make the closed skin close to the lining, otherwise the skin will loose. There will be different noises when opening or closing the engine cover or the luggage compartment lid, and the resonance will also happen during driving.

Heat insulation, moistureproof and noise prevention treatment of 2. body floor

On the upper surface of car body, we must polish the metal surface of sheet metal components and welding parts and spray antirust primers. After drying, paste the original factory's same type body soundproof lining or sound insulation pad to absorb vibration and noise generated by vehicle motion.

For the lower surface of the floor (a body outside), should be first exposed metal surface and repair after thoroughly cleaning the grinding, paint around the factory to be off the cleared completely, spraying 1~2 layer antirust primer, after drying, in combination with the surface and the gap filling of MSP body sealant or similar products. Spraying antirust primer collision. The body floor, which is treated like this, can enhance the corrosion resistance and reduce the impact of the stone strike noise on the car.

With the increasingly fierce competition in the automotive market and the increasingly updating of vehicle manufacturing and repair technology, the basic painting process has attracted the attention of automobile manufacturers and maintenance service personnel. A wide variety, complete specifications and good functional coating materials will undoubtedly further promote the improvement of the maintenance quality and promote the extension of the service life of the car.