2. Shock Absorption & Noise Isolation
(1) Body structure (Fig. 5-37)
a. Arrange the reinforced bar reasonably to improve the parts' rigidity, reduce the shock and lower the noise.
b. Apply the sealant in the floor seam to improve the floor sealing and reduce the noise in the cabin.Fig. 5-37 Front Wall Panel
1. Front wall bridge reinforced panel
2. Front wall mid-frame panel
3. Front wall lower main panel
4. Heat-isolated pad
Fig. 5-38 (a) Body floor
1. Front mud guard 2. Rear side wall 3. Rear wheel housing 4.Floor sides (2) Deadening
It is an interactive and systemic work to make the body isolate heat, shock and noise. Besides the measures
carried out to improve the body's stiffness and sealing performance, the following measures shall be taken in the
design and manufacture process.
a. Sound isolation material: add sound isolation pad on the front wall and floor.
b. Sound absorption material: add molded carpet on the front floor and rear floor.
3. Sealing
Special consideration has been given to the sealing of the body both in design process and in manufactureprocess. Sealing plays an important role in many aspects, such as dust resistance, water resistance, corrosionresistance, heat resistance, heat preservation, and noise reduce etc. Especially when the body floor and front wall
stay in a tough external condition, the mud, dust, noises (from the tire and engine) and hot air will invade into the
cabin any time.
After the body assembly is welded, sealant will be employed on all joints to prevent the water and steam
penetrating into the metal seam and ensure the quality of subsequent painting.
In addition, a thick layer of impact-proof PVC coat is applied on the base of the body, which has excellentsealing performance. For the sealing to those assemblies, the traditional sealing method is used, such as rubber sealBody Repair -Features and Composition of Automobile Body7-251
123Front4
7-35Section 5 Painting Techniques After Body RepairIn the practical use, various factors may cause painting damage, such as traffic accident, component rust,
premature damage due to bubble, and local color change etc. It is necessary to make repair locally as the following
steps:I. Base Processing (Pretreatment)1. Remove the paint, and remove the coating on the plate work.
2. Cut the edges and corners, and polish the metal plate without paint and the uneven paint at the edge.
3. Blow and clean the dust and dirt, and remove the grease with degreasant.II. Primer Processing1. Apply the self-drying primer on the bare metal surface.
2. Leave the primer drying naturally, or dry it with the infrared radiator.
3. Apply the self-drying oily putty or polyester putty on the plate work surface.
4. Leave the putty drying naturally or artificially.
5. Polish the putty manually to remove the uneven parts.
6. Polish it manually in water to clear the sandpaper lines.
7. Wash the dirt, polish the oil dirt and putty slurry.
8. Wipe the oil dirt on the polishing surface.
9. Cover the part not to be repaired with protective shield or paper.III. Painting Intermediate Coat1. Paint the second primer.
2. Leave the primer drying naturally or dry it.
3. Find out the sand hole or sandpaper line.
4. Polish it manually in wet condition.
5. Wash the part clean, and leave it drying naturally. (The number of putty applying and polishing depends on the
evenness of the surface to be repaired.)IV. Preparing to Paint Surface Paint1. Paste paper on the surface not to be painted.
2. Remove the dust and grease on the local surface paint.
3. Mix the color the same with that of the vehicle's surface paint.
4. Prepare the paint.V. Painting Surface Paint1. Paint the part with fast-drying surface paint 3-4 times and synthetic resin paint 2-3 times.
2. Leave it drying naturally or dry it.VI. Polishing1. After painting, burnish the part with wax to clear the shadow and improve the effect.
2. After painting, tear off the paper and wipe the ground paint.
3. Check the appearance and quality.Body Repair -Painting Techniques After Body Repair
