The usage of spotwelder in bodyshops in Malaysia is picking up over the years. This trend is mainly contributed by the standard and repair guidelines released from the OEMs. Authorised repairers don’t have a choice but to follow these guidelines. Spotwelder is not a new technology in the automotive. Its widely used in assembly plants and is now a popular choice in the after market as well. In fact, with new advance steels in the vehicle today, repairers are always encouraged to use spotwelder instead of the traditional MAG welding due to heat affected zone (HAZ).
Advanced steel is not the same as traditional mild steel whereby heat can be applied during repair process. Excessive heat will weakened its structural integrity and it changes its behavior during a collision. Areas where its designed to fail to absorb energy, doesn’t fail at the point of impact. Areas where its strong and hard to protect the passenger safety, fails unpredictably. This is the reason why OEMs, is so strict in their repair methodology as they designed the vehicle to fail in a predictable manner. They won’t be able to tell the behavior of the structure in a collision if the material properties are changed. OEMs have placed tremendous effort and strict repair guidelines to educate repairers of today.
A spotwelder is a compulsory equipment in a bodyshop. In any areas to join that you can reach with a spotwelder, use it. These are the minimum specifications that you need on a spotwelder that is recommended by most of the OEMs:
- Welding current must be at least 10,000 amps and above. Many equipment manufacturer is making spotwelder that has maximum welding current of 13,000 to 15,000
- Automode is a must. The machine must be able to work automatically without the need to enter material type and thickness. The machine will send a pre-current to measure the resistance in between the metal sheets. From the reading, the machine will be able to calculate the optimum current and welding time needed to make a good spot
- Clamping force of minimum 300daN. To make a good spot weld, the machine must be able to provide a clamping force of at least 300daN during welding. This is to ensure a good fusion.
- Watercool to the electrode tips. The coolant must circulates around the machine up to the tips of the electrodes. This is to ensure optimum cooling of the entire machine and electrodes to make continuous spotwelds. Traditional aircooled machine is not recommended anymore as the cooling system is inefficient and at most can do 20 continuous spotwelds.
These are the 4 critical criteria to consider durig consideration of investment. Choose wisely, choose one machine that can cater for repair of all vehicle make.
“Follow OEMs Repair Methodology”