10.25. Anticorrosive protection of a body

Hollow profiles of a body, the bottom, the bottom parts of doors and racks, and also connections of details of a body, including a spot welding place are most of all subject to corrosion. Most quickly corrosion develops in the latent cavities and the bottom parts of a body at hit of a moisture, a dirt, salts, acids.

In this connection while in service the car for additional protection of internal surfaces and the latent cavities of a body put special anticorrosive structure, and in connections of details – sealing mastics. Applied materials for anticorrosive processing are specified in tab. 10.1.

The structure name	Mark	Working viscosity, with, at 20 °С on ВЗ-4	Kind of solvent, Thinner	Drying mode
				Temperature, °С	Time, mines
Autopreservative of thresholds	Мовиль Мовиль-2	15-40	Uajt-spirit, Gasoline	20	20-30
Protective lubricant non-drying	NGM-ML	45	Uajt-spirit	20	15
Protective film covering	НГ-216Б	18-22	Uajt-spirit, Gasoline	20	20
Mastic the antinoise bitumen	БПМ-1	High viscosity	Ксилол, сольвент	100-110	30
Plastic compound полихлорвиниловый	Пластизоль Д-11А	The same	-	130	30
Plastic compound	Пластизоль Д-4А	>>	-	130	30
Mastic non-drying	51-G-7	>>	-	-	-

Autopreservative "Movil" or "Movil-2" is used for processing of the latent cavities. It is recommended to process cavities every 1-1,5 year. Autopreservative supposes processing of surfaces, before covered нигролом or other oils, and also rusty surfaces.

Protective lubricant "NGM-ML" is applied to processing of the latent cavities. This material processes the latent cavities of new cars.

The protective film covering «НГ-216Б» is used for a covering of parts of the car under a body. Mastic antinoise bitumen «БПМ-1» is applied to protection against corrosion of the bottom of a body and for noise reduction. A thickness of a covering of 1,0-1,5 mm.

Пластизоль «Д-11А» it is used for protection of the bottom of a body against corrosion, against abrasive deterioration and for a noise isolation. A thickness of a covering of 1,0-1,2 mm. Пластизолем «Д-11А» the bottoms of new cars are processed.

Пластизоль «Д-4А» it is applied to hermetic sealing of welded seams. Non-drying mastic "51-G-7" is used for hermetic sealing of joints of a body. In internal cavities anticorrosive substance напыливается in the way of air and vacuum dispersion.

At air dispersion compressed air with pressure 0,5–0,8 МПа, a pistol-kraskoraspylitel with a tank, hoses and lengthening nozzles for a pistol is required. Better quality of a covering is reached at vacuum dispersion under the pressure of 4–12 МПа which allows распыливать materials of considerable viscosity.

In view of application of the difficult process equipment and necessity of high-quality performance of works processing of the latent cavities is recommended to be carried out at servicing deports of cars.

Order of performance of operations for protection against corrosion of the latent cavities:

– Establish the car on the lift, remove details and an upholstery, interfering access to the latent cavities;

– Wash out water in temperature 40–50 °С through technological and drainage apertures the latent cavities (tab. 10.2) and a bottom of a body to вытекания at its finest. Thus опускные glasses of doors should be lifted;

The cavity name	Place of injection of structure	Direction of injection of structure	Additional instructions
Cowl cavity	In apertures of the internal panel of a cowl	On all internal surface	Open a cowl
Pockets of forward doors	Through apertures in the internal panel of a door	On all internal surface	Remove upholsteries of forward doors
Pocket of a door of a back	Through apertures in the internal panel of a door	On all internal surface	Remove a door upholstery
Between arches of back wheels	In apertures of cavities in a luggage space	On all surface	Remove an upholstery in a luggage space
Mudguard cavity	From a motor compartment and from under a wheel arch	Downwards and upwards	Will hang out the car
Floor longerons	From salon and from below a body	Forward and back	Will hang out the car
Floor cross-beams	From salon and from below a body	To the right and to the left	Remove rugs
Cavity of a back part of a floor	From below bodies	To the right and to the left	Will hang out the car

– Remove the moisture which has got to salon and a luggage space, blow compressed air all places of drawing of anticorrosive structures;

– Put the car on the lift. Put dispersion anticorrosive structure;

– Lower the car from the lift, clear of pollution obverse surfaces of a body the rags moistened in uajt-spirite.

While in service the car the covering on the body bottom is exposed to influence of gravel, sand, salt, a moisture. As a result mastic and a ground are damaged and erased. The bared metal is exposed to corrosion.

At covering damages пластизоля «Д-11А» without infringement of a layer of earth the damaged sites clear of a dirt and on a dry surface vacuum dispersion or a brush put пластизоль. Dry пластизоль at temperature 130 °С within 30 minutes

Drawing instead of пластизоля antinoise mastic «БПМ-1» which drying can pass under natural conditions is supposed.

Before covering restoration establish the car on the lift, carefully examine a bottom of a body and reveal defects of a covering.

Clear of a dirt a body bottom, remove a rust шпателем, an emery paper or the rust converter according to the instruction. Blow in a body bottom the compressed air. Establish the car on the lift in the chamber for drawing of mastic and remove wheels. Close drums and disks of brakes protective casings, isolate a dense paper and a sticky tape карданную transfer, mufflers, cables and other places which are not subject to processing by mastic.

The rags moistened in uajt-spirite, degrease the places smoothed out to metal.

On the smoothed out places put dispersion or a brush ground ГФ-073 and sustain 5–10 minutes Then put dispersion or manually (a brush or шпателем) mastic «БПМ-1» on defective places a layer of 1,0-1,5 mm. Overlapping on an old coat layer «Д-11А» should be minimum.

In a cold season mastic before the use sustain in a warm premise before rise in temperature not more low 20 °С. In a case загустения mastics dilute it ксилолом, but no more than 3 %.

Paint and varnish covering clear of pollution by mastic by the rags moistened in uajt-spirite. Dry mastic at temperature 100–110 °С during 30 mines or at 18–28 °С not less than 24 ч.

Body hermetic sealing is provided with application of rubber sealants, glues, sealing mastics, the rubber stoppers closing technological apertures, and careful adjustment of interfaced details.

Removing and establishing уплотнители with metal skeletons, do not suppose смятия a skeleton and formation гофр on sealants.

Welded seams do not give full tightness of connections of details, and in case of moisture hit between welded details there there are corrosion centres. From moisture and dirt hit welded seams загерметизированы пластизолем «Д-4А». After replacement of separate details of a body miss the mark welded seams from both parties пластизолем «Д-4А» and put non-drying mastic of type "51-G-7" in angular joints and backlashes.