Volkswagen Golf Service & Repair Manual: Paintwork in Aftersales
| Panels galvanised on both sides |
| Earlier attempts at flanged pairings have resulted in the
fact that only panels that are galvanised on both sides are used
now. Only in this way can the cathodic protection and the
barrier effect of the zinc layer work together to provide
optimum results. In particular, the cut edges which are less
well protected by paint (subject to thinning of the paint
coating at the edge) are provided with additional protection. |
 Note
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that when repairing bodywork all metal edges are properly
deburred. |
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that zinc/electrophoretic primer layer is fully present on
unpainted inner surfaces. |
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that inner weld flanges and sanded-through spots are treated
with INOX spray -D 007 600 A1-. |
| To restore the contours of bodywork surfaces, filler
materials are nowadays considered as an integral part of
bodyshop construction and paintshop operations. Please be sure
to allow for the differing base surface requirements. |
| The primer is the most important component in the corrosion
protection system, as it prevents water and oxygen from getting
to the metal surface. Genuine Parts are usually coated with
black electrophoretic primer. What type of primer is used
depends on the application. |
Note
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Sanded-through spots or weld seams must be re-covered with
an anti-corrosion primer as soon as possible. |
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The electrophoretic primer coating is not resistant to UV
and acid. Consequently, replacement parts must also be painted
from the inside. |
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Isolate areas on which a corrosion damage has been repaired
as well as any bare metal surfaces using 2-pack wash primer -LHV
043 000 A2-, and then apply 2-pack HS Performance surfacer. |
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→ Chapter „Priming metal“ |
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→ Chapter „Priming plastic materials“ |
| The surfacer plays only a secondary role in terms of
corrosion protection. Nevertheless, use of the right surfacer in
Aftersales is essential. |
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Surfacer protects the body against stone chips. So make sure
the surfacer layer is of the appropriate depth in the area
exposed to stone chipping. |
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Surfacer is used to prepare surfaces. Scoring can be
levelled out. |
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Coloured surfacer improves the coverage of shades with poor
coverage. |
| PVC seam sealing and undersealing |
Note
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Seam seals made during repair work must be identical
in appearance and thickness to the original seam seals. |
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To avoid damage or faulty operation, brush seam seals
smooth near attachments which must be attached. |
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Water drainage holes must remain clear. |
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All threaded studs and welded nuts with metric
threads as well as all other studs and contact surfaces for
assembly must be functional following the extent of the
sealing work. |
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Sealant must never be applied to bare metal.
Substrates must always be coated with surfacer first. |
| To prevent water from penetrating into flanges, panel folds
in critical areas of the body are sealed with paste-form,
solvent-free PVC. A varying thickness of PVC layer is also
sprayed onto precisely defined zones on the external floor pan
and in the wheel housings to protect against stone chips and
prevent droning. |
Note
| |
Before sealing/applying underseal, always insulate the
surface with primer and surfacer. |
| |
Isolate areas on which a corrosion damage has been repaired
as well as any bare metal surfaces using 2-pack wash primer -LHV
043 000 A2-, and then apply 2-pack HS Performance surfacer. |
| |
Make sure the underseal layer is of the specified thickness. |
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→ Chapter „Underbody protection“ |
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→ Chapter „Stone chip guard“ |
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→ Chapter „Sealing materials“ |
| The primary role of the top coat/base coat is decorative. It
plays only a secondary role in terms of corrosion protection. |
| The paints have varying coverage depending on their
pigmentation. Pay attention to the manufacturers'
specifications. |
| The primary role of the clear coat is decorative. The clear
coat likewise plays only a secondary role in terms of corrosion
protection. The clear coat protects the base coat against UV
radiation and from environmental damage such as by the acid in
bird droppings. |
| Wax sealing/cavity sealing |
| Wax/cavity sealing plays a key role in terms of corrosion
protection. Various materials are available in Aftersales,
according to the area of application. The outstanding protection
offered by these materials is based on the following properties: |
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Hydrophobic (non-absorbent). |
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Permeability to water vapour some 1,500 times less than a
paint coating of the same thickness. |
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→ Chapter „Anti-corrosion materials“ |
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→ Chapter „Wax-based underseal“ |
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| Reduced paint structure in engine
compartment and inside of bonnet |
Note
| Depending on the model, the paint in the “engine room and
on the inside of the bonnet” may deviate in structure and colour
from the exterior paint. This deviation is production-related
and does not constitute a defect. |
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Structure of a solid-colour (uni) paint finish, conventional
Coat thickness approx. 80-120 µm
1 -
Sheet steel
...
Note
The structure of the underbody and stone chip protection is
to be reconstructed to conform to the original condition in
appearance an ...
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Paintwork structure of a factory finish
Instructions for work on underbody and stone chip protection