Welding FAQs
MIG welding is a process in which an electrode wire is fed through a non-flammable shielding gas (either CO2 or mixed gas) to make high-quality welds quickly on mild and low-alloy steel or aluminum (with the use of a separate spool gun). MIG welding requires that your welding surface and weld joint be prepared with a grinder and most surface contamination has been removed.
TIG welding is a process in which metal filler rod is heated and manually fed into the welding zone created by an electric arc shielded by inert, non-flammable shielding gas. TIG welding is great for making exceptional quality welds on mild steel, low-alloy steel, or aluminum (on machines with AC capabilities). TIG welding requires that your welding surface and weld joint be prepared with a grinder and most surface contamination has been removed.
Stick welding, also known as torch welding, is an electric arc welding process that does not require the use of a shielding gas. Stick gas welding is effective in undesirable conditions such as dirty surfaces or windy and rainy weather. Stick welding machines tend to be compact and portable, ideal for use at a race track or job site.
Flux welding is an electric arc welding process that does not require the use of a shielding gas. An electrode wire is fed through a handheld torch as on a MIG welder. The wire contains as shielding flux core that provides added protection for outdoor welding, making it a good on-the-go option.
A multi-process welder is the latest technology in welding. It combines the functions of a MIG welder, a stick welder, and a TIG welder in a single machine, giving a fabricator the opportunity to tackle almost any job. The addition of a spool gun to an AC TIG-capable multi-process machine allows for welding aluminum for a truly complete welding solution.
Shielding gases used for welding are non-flammable inert (not chemically reactive) or active (chemically reactive) gases that prevent the molten metal being welded from reacting with atmospheric oxygen to ensure a clean weld joint is formed. Typical welding gases include argon (Ar), carbon dioxide (CO2), helium, or a combination of inert gases. The type of gas required depends on the type of metal being welded.
In MIG and TIG welding, flux is not used which means the shielding gas is used to protect the molten weld puddle from the atmosphere. In some cases, combining an inert gas like Ar with an active gas like CO2 helps increase the weld’s penetration.
Shielding gas is required for both MIG and TIG welding. In stick welding and self-shielded flux-core welding, flux on the outer coating of the electrode (stick) or inside the core of the wire (flux core) is used to protect the molten puddle from the atmosphere.
Aluminum can be welded using either a MIG welder or an AC-capable TIG welder. Shielding gas is required when welding aluminum. A spool gun will be required to feed aluminum welding wire through a MIG welder. Dedicated cleaning tools (such as wire brushes) should be used to prepare aluminum material for welding to prevent surface contamination.
Duty cycle is a specification that determines how long a welder can run continuously before it needs to rest and cool down. For example, “30% @ 90A” means a machine is capable of welding continuously for 3 mins at 90 amps of output, but will require 7 mins to rest before welding again. Welding at a lower amperage will increase the duty cycle (65% @ 60A, for instance). The ambient temperature of your welding environment also determines the effective duty cycle of the machine, as warmer temps will result in lower duty cycles.
Many welders are designed to work on typical household power supplies (120V AC/, 20A minimum). Other welders require higher 240V AC, 30A power in order to weld thicker metal. Some welders are designed to work on either 120V or 240V power using a cord adapter. Higher-amperage machines often allow for higher duty cycles.
Operating an AC-powered welder from a portable generator has certain limitations. Welding machines, especially those using advanced technologies or inverter-based systems, may require a stable power source. Portable generators might not always provide the level of power quality needed, leading to potential issues like poor arc stability and increased spatter. These may also produce voltage fluctuations, spikes, or drops during operation. Inconsistent power supply can negatively impact the stability of the welding arc and, consequently, the quality of the weld. Welding machines, particularly those with high amperage requirements, may experience a significant start-up surge. The generator must be able to handle this surge without overloading.
Care must be taken to protect your eyes and skin from the effect of hot sparks and harmful UV light created by arc welding.
- Welding helmets – to protect your face, neck, and head from both.
- Long sleeves and pants – to protect arms and legs from sparks and UV light.
- Welding gloves – provide enhanced heat protection for your hands, which will be much closer to the welding area. TIG welding gloves tend to be thinner than MIG/stick gloves to allow for better dexterity.
Consumables are the materials that are consumed during the welding process. These include:
- Welding wire/electrode - Thin metal filler wire used to fuse the metal pieces together in MIG welding and flux-core welding.
- Welding rod/ filler metal - Metal rod used to fill and fuse metal pieces together in TIG welding and stick welding.
- Gas cylinder - The high-pressure metal bottle that contains the shielding gas used in MIG or TIG welding.
- Tungsten - The metal electrode used to create the welding arc in TIG welding. Tungsten electrodes erode with use and need to be periodically sharpened when welding
- Chipping hammer and wire brush - To remove slag or debris from the surface of the weld.
- Welding magnets and holders - To hold your work in position or at a proper angle to weld safely and efficiently.
- Spool gun - To weld aluminum with a MIG welder.
- Tungsten grinder - To maintain a sharp point on the tungsten electrode in TIG welding.
