Corrosion quickly develops in hidden cavities and lower parts of the body when moisture, dirt, salts, acids get on the surface.
In this regard, during the operation of the car, additional protection is required: the internal surfaces and hidden cavities of the body - by applying special anti-corrosion compounds, and the joints of parts - by applying sealing mastics.
Anti-corrosion compounds for body treatment
| № PP | Name of composition | brand | Operating viscosity, in sec, at 20°according to VZ-4 | Type of diluent, solvent | Drying mode | |
t,°С | time, min | |||||
| 1 | Autopreservative Thresholds | «MOVIL» | 15–40 | White spirit, gasoline | 20 | 20–30 |
| 2 | Protective lubricant, non-drying | NGM-ML | 45 | White Spirit | 20 | 15 |
| 3 | Protective film coating | NG-216B | 18–22 | White spirit, gasoline | 20 | 20 |
high viscosity | xylene, solvent | 90 | 30 | |||
| 4 | Antinoise mastic | BPM-1 | (or 24 hours at 18–20°C | |||
| 5 | Plastic compound polychlor-vinyl | D-4A | high viscosity | – | 130 | 30 |
| 6 | Non-drying mastic | 51-G-7 | high viscosity | – | – | – |
The materials used for anti-corrosion treatment are indicated in the table. Auto Preservative «MOVIL» used for processing hidden cavities. It is recommended to treat cavities every 1–1.5 years. It is allowed to treat surfaces previously coated with nigrol and other oils, as well as rusty surfaces.
Protective lubricant NGM-ML is used in the treatment of hidden cavities. The cavities of all new cars are treated with this material.
Protective film coating NG-216 B is used to cover parts of the car under the body.
Anti-noise bituminous mastic BPM-1 is used to protect the underbody from corrosion and to reduce vibration noise. The mastic is applied by spraying or manually with a thickness of 1.0-1.5 mm.
Plastisol D-4A is used for sealing welds on the outer areas of the body.
Non-drying mastic 51-G-7 is used to seal body joints.
The anti-corrosion agent is sprayed into the internal cavities by air or airless spraying.
Air spraying requires compressed air with a pressure of 0.5–0.8 MPa, a paint spray gun with a reservoir, hoses and extended nozzles for the gun. The best coating quality is achieved with airless spraying at a pressure of 4–12 MPa, which allows spraying materials of significant viscosity.