501-25A Body Repairs- General Info: Description And Operation (page 11 of 15)

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. For additional information, refer to   

Specifications

 (501-20B ) 

Do not allow electronic modules or lines to come into contact with the ground connection or the welding electrode. 
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.  

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 co-ordinating 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). 

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). 

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 and ultra high-strength 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 
90° to the contact surface. The electrodes work best if their shape is convex. Clean the contact surface of the 
electrodes regularly. 

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 and ultra high-strength 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 90° to the contact surface.  
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 
spot-welding equipment have different validity, depending upon the type of equipment. Therefore, it is essential that the 
equipment manufacturer's instructions are observed with regard to the actual welding performance. 
 

MIG / MAG welding 

Setting up the equipment and co-ordinating 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