The table below shows whether body of Bmw 3 E21, made from 1975 to 1983, is galvanized and the quality of processing. Print
Year
Processing
Type
Method
Car body condition
1979
No
No
• applying conventional anti-corrosion layer • use of branded RS steel
Result of processing: Bad Car's 45 years old.Considering the car's age and quality of the zinc processing, under normal operating conditions corrosion spreads in extensive stage.Such cars have repeatedly used measures to eliminate severe rusting.
1980
No
No
• applying conventional anti-corrosion layer • use of branded RS steel
Result of processing: Bad Car's 44 years old.Considering the car's age and quality of the zinc processing, under normal operating conditions corrosion spreads in extensive stage.Such cars have repeatedly used measures to eliminate severe rusting.
1981
No
No
• applying conventional anti-corrosion layer • use of branded RS steel
Result of processing: Bad Car's 43 years old.Considering the car's age and quality of the zinc processing, under normal operating conditions corrosion spreads in extensive stage.Such cars have repeatedly used measures to eliminate severe rusting.
1982
No
No
• applying conventional anti-corrosion layer • introduction of branded steels with BH
Result of processing: Bad Car's 42 years old.Considering the car's age and quality of the zinc processing, under normal operating conditions corrosion spreads in extensive stage.Such cars have repeatedly used measures to eliminate severe rusting.
1983
No
No
• applying conventional anti-corrosion layer • use of low-carbon branded steels with BH
Result of processing: Bad Car's 41 years old.Considering the car's age and quality of the zinc processing, under normal operating conditions corrosion spreads in extensive stage.Such cars have repeatedly used measures to eliminate severe rusting.
The information in table is collected from open sources and may contain errors.About sources
Full-body — the car body is fully processed, including hidden and hard-to-reach cavities.
•
Partial — all nodal points and most vulnerable parts of the car body, thresholds, bottom, bottom of the doors are processed.
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Nodal points processing — includes only processing of welding places, fasteners, stamping and other small parts.
Over years the processing is changed. The younger car the better it's galvanized!
Galvanizing methods
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Hot-dip Galvanizing — best method (high corrosion resistance, resistance to mechanical influences, partial regeneration).
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Electroplating — good method (less corrosion resistance that matches perfectly with the paint and primer).
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Zincrometal — acceptable method (metal with an elastic coating on a zinc base, low anti-corrosion properties, low resistance to mechanical influences).
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Cold Galvanizing — bad method (anaphoretic soil with an admixture of zinc is not able to resist corrosion).
Steel with a protective coating based on zinc - zincrometal, it contains three components:
1 — zincrometal (zinc solution in epoxy resin) 10-20 microns
2 — dacromet (zinc variance inchromic acid water solution) 2-5 microns
3 — sheet of steel
The presence of zinc particles in ground covering the car body does not affect it's protection and is used by the manufacturer for word "Zinc Coated" in advertising.
Testing
Test results of cars that came off the conveyor with the same damage (cross) on the bottom of front right door are presented below. The tests were carried out in laboratory. Conditions in a chamber with hot salt fog for 40 days correspond to 5 years of normal operation.
Car with Hot-dip Galvanizing (zinc layer 12 - 15 microns)
Over the years manufacturers have improved the galvanizing technology of their cars. The younger the car the better it is galvanized!
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A coating with a thickness of 2 to 10 microns (micrometers) provides excellent protection against the occurrence and spread of corrosion damage.
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The destruction rate of the active zinc layer in the place of damage to the car body is from 1 to 6 microns per year. Zinc is more actively destroyed at elevated temperatures.
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If the manufacturer does not add "full-body" to the term "galvanizing", it means that only impact-prone elements have been processed.
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Pay more attention to the presence of a manufacturer's warranty on the car body than loud phrases about galvanizing from advertising.