Looking to upgrade your welder to a unit with more features and versatility? What exactly is the difference between MIG and TIG welding? See our Welding Buyer’s Guide for information on selecting the right welder for your repair or metal fabrication needs. You’ll find a quick overview on the welding process, what to consider when choosing a welder and commonly used welding terms.

The Welding Process

Welding is a process for joining or fastening two pieces of similar metals (workpieces) by melting and fusing 1) the base metals being joined and 2) the filler metal applied. Most commonly, workpieces are welded by melting both of them and adding more molten metal or plastic to form a pool that cools to form a strong joint. The energy to form the joint between metal workpieces most often comes from a flame (e.g. oxy-acetylene) or an electric arc. Most welding involves ferrous-based metals such as steel and stainless steel. Welding covers a temperature range of 1500º F - 3000º F. Weld joints are usually stronger or as strong as the base metals being joined.

Whereas soldering uses solder, a lower-melting-point material, welding applies enough heat to melt the materials being joined.

Plasma Cutting

Plasma cutters are ideal for cutting and fabricating metal — from thin sheets, to thick beams. Plasma cutting employs a torch which uses a powerful electric arc to create plasma, made by boosting a gas (nitrogen, argon or oxygen) to a very high temperature. This creates a stream, or cone, of directed plasma that can reach a temperature of 30,000°F. Handheld torches can usually cut up to 1/2 in (13 mm) thick steel plate, and stronger computer-controlled torches can pierce and cut steel up to 12 inches (300 mm) thick. Unlike laser cutting, for example, the process of plasma cutting is only effective on materials that conduct electricity.

Understanding the Welding Process

Shielded Metal Arc Welding (SMAW) - Stick

This process uses a consumable electrode to support the arc. Shielding is achieved by the melting of the outer flux coating on the electrode. Filler metal is obtained from the electrode core.

• Good for windy, outdoor conditions
• OK to use on dirty or rusty metal

Recommended metal: Steel, stainless steel, cast iron
Skill Level: Moderate

Gas Metal Arc Welding (GMAW) - MIG

A process used with a wire feed welding machine. Metals are joined by heating them with an arc, which is between the continuously fed filler metal electrode (solid wire) and the workpiece. Externally supplied gas or gas mixture provide shielding.

• Easy process to learn
• Better control on thinner metals
• Cleaner welds with less slag to clean
• Equipment can be used for Flux Cored welding

Recommended metal: Steel, stainless steel, aluminum, cast iron
Skill Level: Low

Flux Cored Arc Welding (FCAW) - Gasless

Process that uses a wire-fed welding machine. Metals are melted and joined by heating them with an arc between a continuous, consumable electrode wire and the workpiece. The weld is tubular with flux material contained inside the shielding. Added shielding may or may not be supplied from external gas or gas mixture, depending on the type of flux cored wire being used.

• Works well on dirty or rusty material
• Deep penetration for welding thick sections
• Can be used with or without shielding gas
• Self-shielded wire are best for windy conditions

Recommended to weld: Steel, stainless steel
Skill Level: Low

Gas Tungsten Arc Welding (GTAW) - TIG

This process uses welding equipment with a high-frequency generator. The arc is created between a nonconsumable tungsten electrode and the workpiece. Filler metal may or may not be used, and argon inert gas or inert gas mixtures are used for shielding.

• Provides high-quality, precise welds
• Highly aesthetic weld beads

Recommended metal (AC TIG): Aluminum, magnesium alloys (DC TIG): Steel, stainless steel, copper, brass, titanium
Skill Level: High

Resistance Spot Welding (RSW)

Two separate pieces of metal are joined by passing current between electrodes positioned on opposite sides of the workpieces. No arc is used; rather, it is the resistance of the metal to the current flow that fuses the pieces.

• Portable and easy to operate
• Ideal for light industrial applications

Recommended metal: Steel, stainless steel
Skill Level: Low

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What to look for when choosing a welder

Typical Applications

Consider the most common uses and applications for your welder: construction, farm/ranch, general maintenance/repair, home, auto body/repair, etc. Welders are designed for certain applications, depending on rated output, duty cycle and other features. For example, heavy-duty repairs in the field requires a welding package that can handle different types and sizes (thickness) of metal, whereas repairing a wrought iron railing can be done using a stick welder.

Available Power Input

• Single-phase products require single-phase input power usually found in homes and garages (Welders operate off either 115 or 230 Volts)
• If electrical hook-up is not available, a gas-powered, engine-driven welding generator can supply welding and auxiliary power.

Portability

• Can the welder be brought to the workpieces, or do the workpieces need to be brought to the welder?
• Accessories can be used to make most welders portable
• Hand-portable welders are typically 70 lbs. or less

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What to look for in a welding helmet

Auto-Darkening vs. Standard Glass Lens

Auto-darkening allows easy starting and positioning in welding. With standard glass, the welder needs to be able to flip the helmet down at the moment the weld starts, and flip the helmet up to view the workpiece before beginning again. The downside of this type of helmet is a potential loss of torch position on starts, and at times the helmet cannot be flipped because of space restrictions.

Solar Power vs. Battery (how about both?)

Most solar-powered helme