Land Rover Discovery: Safety Measures

• The electronic control modules (ECM) fitted to vehicles make it advisable to follow suitable precautions prior to carrying out welding repair operations. Harsh conditions of heat and vibration may be generated during these operations which could cause damage to the modules. In particular, it is essential to follow the appropriate precautions when disconnecting or removing the airbag RCM.
• Do not allow electronic modules or lines to come into contact with the ground connection or the welding electrode.
• Seat belt anchorages are a safety critical. When making repairs in these areas, it is essential to follow design specifications. Note that extra strength low alloy steel may be used for seat belt anchorages. Where possible, the original production assembly should be used, complete with its seat belt anchorages, or the cut line should be so arranged that the original seat belt anchorage is not disturbed.
• All welds within 250mm (9.842) of seat belt anchorages must be carefully checked for weld quality, including spacing of spot welds.
• Remove the battery before carrying out welding work in its vicinity.
• Utmost care must be taken when welding near the fuel tank or other components that contain fuel. If the tank filler neck or a fuel line must be detached to allow access for welding work, then the fuel tank must be drained and removed.
• Never weld, on components of a filled air conditioning system. The same applies if there is a risk of the air conditioning system heating up.
• Connect the ground connection of the electrical welder directly to the part that is to be welded. Ensure that there are no electrically insulating parts between the ground connection and the welding point.
• Adjacent vehicle parts and adjacent vehicles must be shielded against flying sparks and heat.

RESISTANCE SPOT WELDING

Where resistance spot welds have been used in production, they must be reproduced with new spot welds in replacement where possible. All such reproduction spot welds should be spaced 25 to 30mm apart.

Setting up the equipment and coordinating the welding parameters.

Equipment:

• Follow the equipment manufacturer's instructions for the equipment settings.
• Select the correct electrode arms (as short as possible).
• Align the electrode arms and tips exactly.
• Electrode tips should be convex (rough shaping with a file, fine shaping with a sanding block).

Body:

• Ensure that the flanges to be joined lie perfectly flat to one another.
• Prepare a bare metal joint surface (inside and outside).

Notes on technique/method:

• Carry out a test weld on a sample piece of the material coated in welding paste.
• If any metal parts are located between the electrode arms then there will be a loss of induction and therefore power (adjust current setting).
• The power needs to be adjusted for high-strength low alloy steel.
• Repeated welding on old welding points often leads to poor quality welds.
• Keep the electrode tips as near as possible to an angle of 90º to the contact surface.
• Keep the pressure on the electrodes for a short period after finishing the weld.
• The electrodes work best if their shape is convex. Clean the contact surface of the electrodes regularly.

Resistance spot welding panels where the total thickness is 3 mm or more

For all repairs to modern Land Rover vehicles, spot-welding equipment should be suitable for reliable welding of zinc-plated, high-strength and high-tensile steels in three or more layers, up to 5 mm total thickness. If these requirements are not fulfilled, plug welding must be used for safety reasons. The electrical specifications (current, resistance, heat) of the spotwelding equipment have different validity, depending upon the type of equipment. Therefore, it is essential that the manufacturer's instructions are observed with regard to the actual welding performance.

MIG/MAG WELDING

Setting up the equipment and coordinating the welding parameters.

• Any joins that are MIG/MAG welded in production must also be MIG/MAG welded during repairs. Also during repairs, some resistance spot welds need to be replaced by plug welds.
• If access is difficult, or if a suitably powerful spot welder (see above) for total panel thicknesses of 3 mm or more is not available, resistance spot welding must be partially replaced by plug welding during repairs. In this case, the increased time needed and the correspondingly more demanding corrosion protection requirements, must be taken into account.
• Welding repairs can only be carried out properly if the equipment is set up correctly and all the welding parameters are co-ordinated.

Equipment:

• Set up the equipment as directed by the manufacturer.
• The hoses must be untwisted.
• The core must be free of abraded rod particles.
• The gas and current nozzles must be free of slag and scale residue.
• Pay attention to the quality of the welding rod and the throughput of gas.

Body:

• Ensure that the joint surface is perfect.
• Prepare a bare metal joint surface.
• Maintain the correct gaps (formation of roots).

Notes on technique/method:

The increased application of heat during MIG welding destroys the welding primer/zinc layer over a much larger area than during resistance spot welding, as a result of which much more care needs to be taken when applying anti-corrosion protection afterwards.

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

NOTES:

• The increased application of heat during MIG welding destroys the welding primer/zinc layer over a much larger area than during resistance spot welding, as a result of which much more care needs to be taken when applying anti-corrosion protection afterwards.
• A test weld should always be carried out to ensure that the welded joint is not just a surface connection.

Attach the ground cable right next to the welding point (ensure that good contact is made).

During plug welding start welding on the lower panel to ensure adequate penetration.

Plug welding

1. Welding direction: circular pattern working from the inside outwards
2. Welding starting point: center of hole on lower panel

Panel BeatingBonded Glazing

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