Ford Workshop Service and Repair Manuals

Before the welding process, you must carry out the following operations:

• 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.

Interrupted weld seam - intermittent seam

The intermittent seam is used for offset joint surfaces or for butt joints with a metal insert. This form of seam is mainly used on the external panel area for sectional repairs.

Please note the following welding parameters:

• Weld gap.
• Spot weld interval.
• Apply alternate tack welding across the entire length of the seam. This keeps warping to a minimum.

Puddle weld.

Puddle welding is used as a substitute if no spot welding equipment that is sufficiently powerful for the thickness of the panel is available. This welding method is also used if the welding position cannot be accessed with a spot welding gun.

NOTE:A test weld should always be carried out to ensure that the welded joint is not just a surface connection.

Please note the following welding parameters:

• The panels to be joined must lie perfectly flat to one another.
• The panel flanges must be bare at the welding position. Treat other areas with corrosion protection.
• 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.

Resistance spot welding.

The basic principle for repair welds is to restore the original welded joint as far as possible.

NOTE:Before starting the work, please refer to the chapter on safety instructions.

The repair welds must have the same number of weld spots as the welds used in production with the correct diameters.

This requires that:

• The panels to be welded overlap.
• The weld spot is accessible on both sides for the electrodes.
• The shape and alignment of the weld electrodes is correct.
• The resistance welding equipment is powerful enough to reproduce the spot weld diameter used in production.

NOTE:The welding equipment settings and the adjustment of the individual parameters are to be made in accordance with the device manufacturer's specifications.

Well-prepared welding flanges are a prerequisite for a problem-free welded joint. This means:

• The welding flanges must lie perfectly flat to one another.
• The welding flanges must be clean and free of oil or grease on both sides.
• Welding primer (zinc-coated and conductive) must be applied as corrosion prevention.

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.

Joining techniques

Butt joints

The butt joint is a joining technique frequently used in body repairs. The butt joint is typically used for repairs in the pillar and rocker panel area.

Areas that are suitable for the use of the butt joint:

• short seam lengths.
• highly profiled structures.
• mostly thin panel thicknesses.

The edges of the panels to be joined are placed against each other and are joined with a full seam in whilst maintaining a required welding gap (welding gap same as panel thickness).

NOTE:The butt joint requires a high degree of accuracy and care when trimming and cutting. For correct execution of the welding, an exact, even welding gap must be maintained.

Preparation of the joint areas includes:

• Sanding the connection areas bare on both sides.
• Removal of the zinc layer in the welding area.
• Carrying out welding tests on an equivalent sample panel before the actual welding, if necessary.
• Tack welding in the join area: From the edges to the centre, then check the shape.
• Joining new and old parts with a full seam weld.

Butt joint with panel strip

As with the butt joint without a panel strip, the panels to be joined are pushed together, but are joined with an intermittent seam. A panel strip placed beneath the area to be joined stabilizes the welding area.

Preparation of the joint areas includes:

• Preparation of a panel strip approx. 30 mm wide.
• Grinding the joint areas and the panel strip to bare metal on both sides.
• Removal of the zinc layer in the welding area.
• Carrying out welding tests on an equivalent sample panel before the actual welding, if necessary.
• Tacking the panel strip to the old part with several resistance spot welds.
• Joining the new and old panel with an intermittent seam.
• Lead loading the weld seam.

Joggled joint

The joggled joint variant is restricted to body areas with a good surface condition without beads/swage lines or profiles. A sectional replacement with a joggled joint is welded with an intermittent seam. This procedure is used, for example, at the transition from the side panel to the rocker panel (3-door vehicles).

The amount of reworking required is kept to a minimum, by avoiding the use of a full seam. Other advantages are:

• Heat-induced warping caused by the welding procedure is low, as intermittent seam welding only applies a little heat.
• When cutting the new part, slight measuring tolerances are permitted, as these are covered by the joggled area.

Preparation of the joint areas includes:

• Sanding the connection areas bare on both sides.
• Removal of the zinc layer in the welding area.
• Preparation of a joggled strip.
• Carrying out welding tests on an equivalent sample panel before the actual welding, if necessary.
• Joining the new and old panel with intermittent seam welding.
• Lead loading the weld seam.

MIG brazes

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

In areas in which 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.

NOTE:At the time of printing, MIG brazing has still not been approved for repair in the workshop. Please find out the current status.

MIG brazed connections are partly used in production for the following areas: Inner fender reinforcement to A-pillar, A-pillar reinforcement to A-pillar inner panel and outer wheelhouse to rocker panel reinforcement.

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:

• No corrosion of the brazed seam.
• Low erosion of the zinc coating in the joining area.
• Minimal destruction of the coating on the reverse side of the panel.
• Low level of heating and thus little warping.
• Easy finishing of the brazed seam.
• Good for bridging gaps.

NOTE: MIG welds must not be carried out on or near existing MIG brazed seams as even the smallest amount of brazing solder can result in a reduction in the strength of the weld seam.

Alternative repair methods are specified in the model-specific body literature.

MIG brazing requires a new generation of welding equipment and training in the technique. For this reason, MIG brazed joints must be replaced by MIG welds at another place if a repair is performed.

When carrying out these repairs, the requirements in the corresponding repair instructions must be taken into consideration.

Rivets

With riveting, two or more panels are joined together using a joining element (rivet). In body construction, pop rivets and punched rivets are used.

Advantages of riveted connections:

• Metallic and non-metallic materials can be joined together.
• Different thicknesses of materials can be used.
• The material does not have to be heated, and therefore does not warp.
• Low level of preparation required.

NOTE:For detailed instructions on the procedure, please refer to the equipment manufacturer's operating manual.

Disadvantage:

• During dismantling procedures, swarf/rivet remains can fall into inaccessible cavities, which can lead to rattling and rusting.

Pop rivets are used if only one side of the panel is accessible. In this process, overlapping panels are drilled and connected with a pop rivet.

Pop rivets can be inserted pneumatically, hydraulically or manually with rivet guns.

Brazed connections

Brazing is a procedure for connecting metallic materials using a further melted metal.

The melting point of the brazing material is lower than that of the basic material. The basic material is covered with the brazing material and not melted.

As the material is heated to a lesser extent than during welding, brazing is particularly suitable for parts that are sensitive to warping, oxidization and heating. Brazing means it is possible to join together all common metals.

Brazed connections can be detached again through heating.

Brazed parts have a limited strength, low thermal resistance and a certain risk of corrosion due to the difference between the basic materials used and the brazing material (difference in potential).

NOTE:All connections that are brazed in production must also be brazed if a repair is performed.

Watertight, permanent connections must be produced at the transitions between A or C pillars and the roof. Continuous welded seams in visible areas require time-consuming finishing. For this reason, such connections are not welded, but brazed.

Brazed connections are:

• Very stable and yet elastic.
• Watertight.
• Easy in surface processing.

NOTE:Brazed connections require careful preparation. It is extremely important that the joint surfaces are exactly aligned and that a bare metal joint surface is prepared.

This means:

• Thorough cleaning of the surfaces to be brazed.
• Close contact of the panels at the brazing position.
• The connection/repair position is heated to the melting temperature of the brazing material (approx. 900° C).
• The brazing material is applied to the connection area and heated on the panel to the melting temperature.
• The liquid brazing material is drawn between the panels through capillary action.
• The materials join together at the edges of the panels (alloy formation).

Lead loading

Lead loading with tin is the best repair method for smoothing joins on sectional replacements or for rectifying small uneven areas on the panel surface. 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.

WARNING:Brazes are metal alloys (usually lead and tin). Poisonous gases and dust can be produced during processing. Use an extraction unit and, if required, a protective mask.

NOTE:Since 07/2003, lead compounds have been ruled out for production. In the workshop too, lead-free tin solders must be used.

For correct repair, the panel is beaten out almost to the original shape and then the rest is smoothed out through lead loading. First, the panel to be lead loaded must be properly prepared.

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 slowly, it is worked with the body plane until the surface is smooth and has no visible joints.

Bonding

Bonded connections are used more and more in modern body designs. Here, a distinction is made between bonds for stabilization purposes and bonds for adhesive strength. Bonds for stabilization purposes are found on clinched flanges and on cross beams in doors or on the roof.

WARNING:Risk of poisoning! Adhesive can be harmful to health. Ventilate rooms well and use breathing protection. Where possible, work with an extraction unit.

NOTE:Adhesives are chemical products and are subject to the safety regulations of the manufacturer.

The repair adhesive is an elastic 1K adhesive on a polyurethane basis. Bonds that rely on adhesive strength are used instead of conventional metal connections. Here, the hardening 1K epoxy resin is used.

Bonded connections have the advantage over conventional connection procedures that no heating is required. This means it is not necessary to remove heat-sensitive parts, such as the fuel tank, electronic modules or plastic parts.

In addition, bonded connections have further advantages:

• They are air and watertight.
• High corrosion protection
• Different materials can be connected.
• Bonding can be combined with resistance spot welding.

NOTE:The quality of the bonded connection is largely dependent on the care taken during preparatory work.

Different adhesives are used in body repairs. Please refer to the repair instructions for the specific adhesive to be used. Please also take into consideration the instructions of the adhesive manufacturer.

Body bonding requires the following steps:

• The processing temperature of the parts to be processed must comply with the adhesive manufacturer's specifications.
• The connection surfaces must be even and perfectly flat to one another.
• Sand the connection surfaces bare. Use only completely dirt and grease-free tools to do this.
• Clean the connection surfaces with the special cleaner provided by the adhesive manufacturer. Do not use thinner, petroleum ether or other cleaning agents.
• Leave the connection surfaces to dry.
• 

  NOTE:Use protective gloves when applying the adhesive.
  Apply the adhesive to one or both surfaces to be bonded, according to the manufacturer's instructions, using a suitable tool.
• Join the parts as precisely as possible immediately after applying the adhesive so that only minor corrections are necessary.
• Fix the parts in the final position with clamps.
• Depending on the adhesive, the hardening process can be accelerated using a hot air blower.
• Finally, clean the area that has been bonded of leftover adhesive.

Bonding and welding

On some vehicle models, (such as the Ford Ka), bonding is combined with resistance spot welding. This connection technique has the following advantages:

• Tight, anti-corrosion connection seam.
• High strength due to additional resistance weld spots.

Please note the following points during the repair work:

• Only use adhesive suitable for welding (conductive).
• Carry out resistance spot welding on the connection flanges before the adhesive hardening process.
• Carry out test welding with the adhesive applied.
• If MIG welding is carried out during a sectional repair on a connection flange with adhesive material, the adhesive material must be applied at a distance of approx. 10 mm from the weld spot.

Bonding and riveting

As with welding, bonding can also be combined with riveting. This connection technique has additional advantages. These are:

• Metallic and non-metallic materials can be joined together.
• Different thicknesses of materials can be used.
• The material does not have to be heated, and therefore does not warp.
• The rivet connection stabilizes the connected components during the adhesive hardening phase.