Ford Fiesta (2011 year). Manual - part 98

If the damage is concentrated in a spot and is in
the form of a more rigid raised area, then the
carbon electrode must be replaced by a copper
electrode. As heat is applied, slightly more pressure
is applied to the raised area.

In the method using heating by the oxy-acetylene
torch, material shrinking is achieved by a
combination of heat and mechanical working of the
damaged area.

Description

Des

cript

ion

Overstretched area

Point heating using the oxy-acetylene
torch

Spiral shaped knocking back with dolly

The repair area must always be accessible from
both sides, so that the heated area can be properly
worked mechanically.

The combination of heating and mechanical
working is very effective.

As soon as the warm point is established,
hammering is immediately started using the
aluminum hammer together with a suitable dolly
on the inside of the repair surface, working in spiral
movements towards the warm point. This causes
material to build up in the center of the warmed
area.

Lead loading

Despite good external panel beating techniques,
it is not always possible to rectify every surface
unevenness. For this reason, application of lead
loading is an important part of panel beating.

CAUTION: Poisonous gases and dust can
be produced when working solder. Use an

extraction unit and, if required, a protective
mask.

NOTE: Since 07/2003, lead compounds have been
ruled out for production. Appropriate lead-free tin
solders and pastes must also be used in the
workshop.

Typical application areas:

• Body components with limited or no access from

the rear.

• Body components with very narrow

cross-section.

• Body components which are particularly

exposed or which can move.

• Weld seams of partial repairs.

• Rocker panel areas, wheel arch edges, side

panel areas.

• Doors, hood, luggage compartment lid.

• Swage lines and joint areas.

Tin has the following advantages:

• Excellent bonding on bare metal surfaces.

• Good moulding properties.

• Good properties for the production of shapes

and contours.

• Permanent shape.

• Heat expansion is the same as steel.

To create a basis for the actual lead loading
process, a lead loading paste is first applied to the
panel. The paste is then heated and wiped away
with a cloth. Now the tin can be applied and
moulded with a brazing block.

After the repair site has cooled down, it is worked
using for example the body plane until the surface
is smooth and has no transitions.

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DESCRIPTION AND OPERATION

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Paintless Dent Removal

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

General

Application is restricted to body surfaces which are
accessible from both sides. This repair technique
is seldom feasible on double-skinned body
components or closed body profiles. The same
applies to edge areas, swage lines and seams on
body components, which are very dimensionally
stable.

The following characteristics must be present for
a dent to be removed:

• The diameter must be no more than 50 mm.

• No material stretching in the centre of the dent.

• Repair area must be accessible

Furthermore, sufficient experience in the use of
special tools and knowledge of materials are also
requirements for a successful repair.

Description

Item

Deflection by a hook arrangement

Pressure tool

Mild dent

Satisfactory repair results are only possible on mild
dents with little depth and small deformation radii.
Therefore this repair method is particularly suitable
for hail, parking and transportation damage.

Dent with material stretching

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DESCRIPTION AND OPERATION

201

If strong and direct force during the damage
process causes the material to stretch in the middle
of a dent, then the result is a small and sharp
edged dent. Such damage cannot be rectified
without visible deformation.

Advantages of a planishing technique:

• Economical in time and materials

• The original paint is retained

• Environmentally friendly (no sanding or painting

work)

While carrying out the repair, the following itemized
repair route and process flow must be complied
with:

1. Damage diagnosis

2. Repair preparations

3. Perform repair

4. Paint finishing, corrosion protection and quality

control

In order to ensure corrosion protection, all inner
areas of the repair must be treated afterwards.
Where it is possible, the paint is repaired. In every
case the inner area of the repair must be treated
with cavity wax.

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Plastic Repairs

General

The proportion of plastics used in vehicle
construction continues to rise. Up to now damaged
plastic components often had to be replaced.
These days, plastic repairs are becoming more
and more widely accepted because of the
increasing cost of spare parts.

NOTE: Plastic adhesives are chemical products
and are subject to the safety instructions of the
manufacturer.

In repair work, the material properties of plastics
are highly significant. There are two main groups:

• Thermoplastics.

• Thermosets.

NOTE: Elastomers make up a third group of
plastics. These are not mentioned below because
they have no plastics repair applications.

Thermoplastics

Heat causes thermoplastics (also called TP
polymers) to transform from the solid state into the
thermoelastic state and then into the thermoplastic
state. When thermoplastics are cooled, they return
to solid state.

Plastic

Brief

descrip-

tion

Acrylonitrile butadiene styrene

copolymer

ABS

Polyamide

Polycarbonate

Polypropylene

Polypropylene/ethylene propylene

diene copolymer

PP/EPDM

Polycarbonate/polybutylene tereph-

thalate

PC/PBT

Polyvinylchloride

Hard PVC
/ soft PVC

Thermosets

Thermosets (also called TS polymers) are much
harder and more brittle than thermoplastics. Their
strength remains largely unchanged when they are
heated. Thermosets are destroyed when heated

above the critical temperature. Also, the original
state will no longer be restored on cooling.

Plastic

Brief

descrip-

tion

Glass reinforced plastic

GRP

Close-meshed cross-linked poly-

urethane

PUR

Wide-meshed cross-linked poly-

urethane

PUR

Plastic identification

Normally the appropriate identifier is marked on
the plastic components used in vehicle
construction.

The capital letter sequences used for this are
standardized in DIN EN ISO 1043-1 and DIN ISO
1629 (for rubber) and can be looked up in the
tables which they contain. In addition the string of
characters provides information about the exact
mixture ratio and the proportion of certain fillers.

Examples of the identification of plastics

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