Getting into welding is a step up for most DIYers, so understanding the different welding methods for your needs is important.
Types of Welding
There are several different ways to attach one piece of metal to another one, but all welding processes involve creating a molten pool of metal that joins different parts together. Most welding equipment uses electrical energy to create enough heat to melt the wire onto the workpiece.
The cheapest welding equipment is usually for arc welding, the commonest form of which is known as stick welding. Stick welders involve you holding the welding torch in one hand and a welding stick in the other and touching them together on a metal surface to make a pool of metal.
Metal Inert Gas, or MIG, is probably the most popular form of welding. For this welding process instead of using both hands, you simply hold the torch, pull the trigger, and a wire is fed from the machine and out of the tip. On contact with the metal surface, the circuit is completed, and the wire becomes molten metal.
Gas and No-Gas MIG Welding
There are two main types of MIG welding- gas and no-gas. Both are types of wire welding- this welding process involves the machine feeding a roll of metal wire from a spool out through the end of the torch, where an electric arc heats it upon contact with a metal surface.
Gas MIG welding processes use bottles of an inert gas like CO2 or Argon connected to the welding machine to create a gas shield around the hot arc, where standard welding wire meets the metal workpiece. The shielding gas stops the weld from oxidising before it joins the metal parts together but this particular welding process can be affected by windy conditions.
In a no-gas welding process, the wire used is hollow and filled with flux core which is used to generate a slag to cover the molten metal when you’re welding. This protects it from outside gases in the environment which weakens the bond you are making. The downside is that there’s more splatter with this kind of welding process, meaning there’s more to clean up afterwards.
TIG Welding
Tungsten Inert Gas, or TIG welding, is another way to attach two pieces of metal together. Like MIG welding, you use bottles of shielding gas to shroud the hot pool of weld from oxidising. Unlike the MIG welding process though, you need to use both hands when working with a TIG welder.
The main difference is that TIG welding doesn’t use a spool of wire fed through a torch head. Instead, you use long rods as you would for arc or stick welding. It’s a welding process favoured by professional welders for “face” welding, when you need to be neat. TIG is a lot slower than MIG welding though, and takes more skill to get accurate results.
Types of Wire
The two main types of welding wire are regular steel wire used in the gas welding process, and hollow wire filled with flux core for no-gas welding. When you pull the trigger on a MIG welding machine, the wire that is fed out becomes a wire welding electrode, completing an electrical circuit that creates a high enough heat to melt it where you want a pool of metal.
Welding wire is available in different thicknesses, depending on the size of weld you want to create. Most light fabrication tasks that the DIYer welder will get involved with don’t need wire much thicker than 0.6 – 0.8 mm. For welding thicker metals, thicker wire up to 1.2 mm is useful for these heavy welding processes, but it requires more power than is available in a domestic setting.
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