Ford Fiesta (2011 year). Manual — part 101

Only in limited cases can welding errors in
resistance spot weld joints be detected from the
outside . Therefore, a test weld should be carried
out before each repair weld. The peel test carried
out after the welding gives information on the
quality of the welding. The spot weld must not flake
off.

MIG welding

Basically, three methods of MIG welding are used:

• Puddle weld.

• Continuous bead welding

• Intermittent bead welding

Fields of application

• Any joins that are MIG welded in production

must also be replaced by MIG welds.

• Puddle welding may be used in certain cases,

if there is insufficient access.

• If the overall panel thickness is greater than 3

mm, without correspondingly powerful spot
welding equipment, puddle welding should be
used.

• When dealing with any MIG brazed joints which

are present, follow the vehicle-specific repair
instructions.

NOTE: The increased application of heat during
MIG welding destroys the corrosion protection
layers over a much larger area than during
resistance spot welding. For this reason, greater
care must be taken when applying the corrosion
protection afterwards.

Welding repairs can only be carried out properly if
the equipment is set up correctly and all
welding-related preparations are complied with
accurately.

• Please note the instructions of the respective

welding equipment manufacturer.

• The hose assembly must be untwisted.

• The core must be free from particles of wire

debris.

• The gas and current nozzles must be free of

slag and scale residue.

• Pay attention to the quality of the welding wire

and the gas flow rate.

• Ensure that the joint surface is perfect.

• Prepare a bare metal joint surface.

• Maintain the correct gaps (root formation).

• Produce a test weld.

Plug Weld

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Special features to note when puddle welding:

• The panels to be joined must lie perfectly flat to

one another.

• The panel flanges must be treated with

corrosion protection. The position of the weld
must be bare.

• Prepare the holes depending on the thickness

and number of the panels. The hole size should
be 6-10 mm, or match the original weld spot.

• Start the welding procedure on the panel at the

bottom so that the hole is filled completely.

Continuous bead welding

A welded joint with a full seam is suitable for joining
highly profiled body parts. Pillar and sill areas are
typical application areas.

Special features to note during bead welding:

• Both parts of the panel must be bare on both

sides over a width of 5 mm.

• Align the parts precisely with clamps.

• To prevent the panel from warping, tack longer

joints before welding them.

Intermittent bead welding

Intermittent bead welding is used when the
connecting flanges are stepped. This form of seam
is mainly used on the external panel area for
sectional repairs.

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Special features to note when intermittent bead
welding:

• Weld gap.

• Spot weld interval.

• Apply alternate tack welding across the entire

length of the seam. This keeps warping to a
minimum.

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MIG brazes

Description

Des

cript

ion

Rear side member / wheelhouse reinforce-
ment

1

Apron panel reinforcement / A-pillar

2

Metal Inert Gas (MIG) brazing is increasingly used
in production for certain body areas.

In areas where resistance spot welding is not
possible due to limited space or higher strength
requirements, MIG welding was previously used.

Increasingly, these MIG welded seams are being
replaced by MIG brazes. The temperature range
used during MIG brazing is significantly lower. This
keeps the damage to the anti-corrosion zinc layer
on zinc-coated panels to a minimum.

This results in the following advantages of the MIG
brazed seam:

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