Ford Fiesta (2011 year). Manual — part 96

Corrosion Damage/Corrosion Repair

Modern vehicle bodies are protected from corrosion
by elaborate measures. Multilayer coatings on the
panel surface prevent direct contact between the
metal and oxygen, and so protect it from corrosion.

In the long-term however, corrosion on a vehicle
cannot be completely prevented.

NOTE: Basic and in-depth training is offered on
the following topics. You will find an overview of
the complete range of training in the Training
Brochure issued by the Ford Service Organization.

What is corrosion?

Corrosion is destruction of a subsurface caused
by chemical or electrochemical effects which
operate from the outer surface.

If the protective layers become damaged,
electrochemical conversion processes are initiated,
which allow the metal to oxidize. This leads to the
formation of corrosion.

The following factors lead to corrosion:

• Mechanical damage such as stone chips and

scratches which penetrate through to the steel
panel.

• Damp interiors.

• Unfavorable weather or environmental

conditions, as may occur in areas with high
humidity, high salt content in the air or serious
air pollution due to aggressive gases and dusts.

• Insufficient corrosion protection after repairs.

• Lack of care by the vehicle owner of the painted

and corrosion proofed surfaces or areas on the
vehicle.

In order to maintain long-term corrosion protection,
the vehicle must be checked at regular intervals.

In doing so, the follow areas must be inspected
and any damage rectified:

• Damage to the paint surface cause by scratches

or stone impact must be suitably rectified
according to the specifications.

• Damage to the PVC underbody protection or

the PU stone chip protection must be refinished.

• Damage to the PVC underbody protection or

the PU stone chip protection must be refinished.

• Incomplete or damaged sealing at clinched

flanges must be renewed.

• Check the cavity protection and renew it if

incomplete.

• Poorly installed or damaged covers and stone

chip protection fixtures must always be renewed.

• Check seals and seal carriers for wear and

correct mounting. Any damaged seals must be
renewed.

• All rubber grommets and blanking plugs must

be present and correctly installed.

• A damp or wet floor inside the vehicle indicates

that there are leaks in the bodywork. The interior
must be dried out and the leaks must be
completely rectified.

The corrosion formation can vary in extent.

With rust film or edge rust formation, the surface
of the paint has small traces of corrosion present.
The traces of corrosion can possibly be removed
in such cases by polishing the paint surfaces. If
this is not possible however, the traces of corrosion
must be rectified by using a touch-up technique.

If the corrosion is just starting, with up to 1 mm
rusting below (in the form of a dot or a line) the
damage is rectified as follows:

• Clean the defective location.

• Mechanically remove the rusting which is

starting below the surface.

• If the area is small, apply primer and allow it to

dry, then use the paint pencil to touch up the
area - if not, respray the damaged area.

If rust is already under the paint finish to the steel
panel, then the whole paint finish in the affected
area must be sanded away.

Furthermore, the existing traces of corrosion in the
body panel must be carefully and completely
removed.

Finally a new paint finish must be applied in this
area. In the case of rusting through, the affected
body panel is already completely destroyed. Such
damage requires complete or at least partial
replacement.

NOTE: : In the general section there are several
chapters which present the techniques necessary
for a professional corrosion repair.

The outcome of this is the following repair
sequence:

• Remove the rusted-through part.

• Remove the remaining traces of corrosion.

• Offer up the new part.

• Prepare the joint areas.

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• Weld the new part into place.

• Produce the corrosion protection.

For a professional repair it is essential to reproduce
the corrosion protection during and after the repair.

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Sealer, Underbody Protection Material and Adhesives

Sealants, adhesives, cavity wax and underbody
protection materials are used during the various
body repairs. In this area Ford offers a range of
products which have been tested and matched to
each other.

CAUTION: Always be extremely careful
when handling solvents, sealants and
adhesives. Some products contain
substances harmful to health or give off
harmful or poisonous vapors. Always
follow the manufacturer's instructions. If
there is any doubt as to whether a
particular solvent is suitable, it must NOT
be used.

Clinched flange protection

One-component adhesive/sealer which can be
applied by brush or spraying, based on MS
polymer, with a flat nozzle for application and with
the following properties:

• Can be sanded

• Permanently elastic

• Non-corrosive

• Very good adhesion

• Rapid hardening and resistant to ageing

• Can be over-painted with almost all proprietary

paints

Seam sealant T Anthracite

One-component sealer based on MS polymer, for
sealing joints and seams, with the following
properties:

• Silicon-free

• Solvent-free and low-odor

• suitable for gluing HVH elements into position

in their respective body areas

Body sealant T beige

Sealer with the following properties:

• Stable

• Contains solvent

• Especially suitable for visible seams

• After hardening can be overpainted with

two-pack paint

Underbody Coating

Underbody protection is necessary for permanently
elastic corrosion protection of vehicle underbodies.

It is very durable and has good resistance to
abrasion,

Cavity wax

This touch-proof, transparent corrosion protection
wax is used for the preservation of cavities and
flange joints.

Anti-corrosion wax

Anti-corrosion wax is a coating material which can
be applied in fine spray, forming a very thin and
grease-like protective film, therefore offering very
good corrosion protection.

2-component metal adhesive

For joining metal to metal and plastic to metal. The
adhesive reduces droning noises and improves
corrosion protection.

Windshield sealant

Solvent-containing, stable sealing material. The
sealer is permanently elastic and does not form a
skin on the surface.

1-component window glass adhesive kit

For direct glazing. The vehicle is ready to drive
after 6 hours (passenger airbag). Prevents contact
corrosion.

2-component window glass adhesive kit

For direct glazing. The vehicle is ready to drive
after 1 hour (passenger airbag). The adhesive is
not an electrical conductor and permits
interference-free radio reception. Prevents contact
corrosion. Using a 150ml additional cartridge, the
adhesive can also be used for large windows or to
produce a double seam of adhesive.

PU glass adhesive

150ml additional/replacement cartridge for direct
glazing using 2-component window adhesive kit.
Suitable for double beads or larger windows. Also
suitable for sealing NVH elements.

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Cutting Technique

NOTE: Without exception, before starting work you
must read the safety and warning instructions in
the chapter "Safety Instructions". In addition, pay
attention to the warning instructions of the particular
equipment manufacturer.

NOTE: After all separation work, make certain that
the metal swarf is completely removed from the
vehicle body.

Possible cut lines (example)

Depending on the separating tools used, there are
some fundamental points to bear in mind:

• Only start the cutting work once the new part is

to hand.

• Compare the new part with the old part for

shape and size.

• The straightening work must be completed

before any body components to be replaced are
cut out.

• Before separation work is started, all welded

connections which cannot be seen must be
freed of underbody protection, sealant etc.

Spot weld milling tool

Resistance spot welds are separated using a spot
weld drilling machine or a spot weld milling tool.

NOTE: Steplessly variable machines increase the
working life of the cutting tool. Use of a suitable
lubricant can increase this even further.

A spot weld milling tool usually has an adjustable
depth stop and a safety fixing system. These
prevent the machine from drilling too deep and the
cutter from slipping while working.

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