HEALTH & SAFETY
Although MIG/MAG is one of the safest forms of arc fusiontype welding, it presents a number of risks. Electric shocks should be minimised if your welder is stored, maintained and set-up correctly, but your car may not be so lucky. In most cases, disconnecting the battery will suffice, but some vehicles require their ECUS to be removed, to avoid damage from the magnetic fields that welding generates.
For this reason, you should seek medical advice before attempting welding, if you are fitted with a pacemaker. Additionally, aim to have the welder’s negative cable as close as you can to your work area, so that the electrical circuit is kept as short as possible.
Keeping your surroundings clear reduces the risk of fire. This includes ensuring that any trim, soundproofing material, cavity wax, etc, cannot ignite within the car. Wear flameretardant overalls, arm sleeves, gauntlets and even an apron. Keep an appropriate fire extinguisher handy and be aware that fabrics can smoulder for hours before igniting.
Welding vaporises the base metal, filler and gas, creating weld fumes, which present a further, unseen hazard. Fume fever, which has flu-like symptoms, can be quite serious, so weld in a well-ventilated area. If you are welding galvanised metal (even lightly galvanised steel, such as Zintec), remove the thin protective coating with a flap-disc so that you do not breathe the vapour. While the argon/co2 gas mixture is mainly inert, it is heavier than air and will displace oxygen, so asphyxiation can be a risk if you are working in a pit and a gas bottle is leaking. While heavy gas cylinders pose a hazard by virtue of their weight, the pressure within them can be up to 2500psi. If they fall over and break their necks, the cylinder can have sufficient thrust to punch through a brick wall (Mythbusters proved this with great effect – see www.
youtube.com/watch?v=c4kb-8cjvyg). Always ensure that the cylinders are chained up, secured and cannot fall.
While welding will not harm your ears (although grinding will), it can cause serious damage to your eyes and skin. Never look directly at the bright arc, as both ultraviolet (UV) and infared (IR) lights are generated. Keep your skin covered with thick clothing and use leather gauntlets to protect your hands from the rays. You will feel IR as heat, which can cause burns to the skin. You can neither see, nor feel, UV but it can result in the short term and deeply uncomfortable ‘arc-eye’, a condition that can cause permanent retina damage in the long term.