MIG Welding

Overview Welding : a process of joining two materials that coalesce at their contacting surfaces through theapplication of heat. Advantage : portable, permanent, stronger than the parent materials with a filler metal; the mosteconomical method of joining in terms of materialusage and fabrication costs. Disadvantage : expensive manual labour, high- energy and important safety considerations; doesnot allow for disassembly, defects can beconcealed.

MIG welding A continuously fed metal electrode (wire) contactsthe base metal and produces heat through an ‘arc’ ofelectrical current. The arc is shielded by an inert gasto inhibit oxidisation.

Typical setup for wire speed The wire feed rate or speed is set using the dial on thewire controller. This setting increases or decreases the current or heat. This setting is measured in amps. Ideal settings can be fixed and monitored by the ampmeter on the front panel of the welder. Ideal settings can be found in the wire manufacturer’sdata book, related to the appropriate current.

Types of joint Butt jointhttp:// jointhttp:// jointhttp:// jointhttp://

Technique Speed of movement is very important.The angle and direction for a right-handedperson.(Left-handed people move to the right, angled to the left.)

Method of welding The following films will show you how to use a MIG welder.Watch and listen very carefully, taking notes, to remember allthe tips that are given in each clip. Remember, the best way tolearn how to weld is practise, practise and practise somemore