You can use arc welding to repair auto panels, mend garden gates, create unique artwork – for dozens of different tasks around the garden and garage. Or perhaps you run a small business and often contract out welding work. How much more convenient and profitable it would be if you could do that work yourself.
Entry-level machinery is increasingly affordable, and experts tell us that even absolute beginners can be competent welders within a couple of weeks. However, choosing the correct equipment isn’t straightforward. There are distinct types of arc welding and differences in technical specifications that have a major impact on suitability for particular jobs.
If you already have a good idea of the type of arc welder you want, our recommendations can point you toward machines that offer great performance and excellent value. For people who need more detailed information, we’ve compiled the following arc welder buying guide.
In 1890, C. L. Coffin of Detroit became the first man to patent an arc welding process using a metal electrode. Though there have been many advances, the basic principle remains the same.
Arc welding methods
Arc welding can be broken down into three types: MIG, TIG, and stick. There are other methods used by specialists that we won’t discuss here.
1. MIG welding uses a gun that automatically feeds a wire electrode. This melts away as the weld is formed. The gun also delivers the gas shield that prevents contamination of the weld. A variation on MIG welding is called “flux core”: instead of gas being supplied by a bottle attached to the gun, it’s part of the wire and released when heated. If you want a general-purpose tool that’s easy to use for welding steel, choose MIG.
Easy to learn
Strong, smooth welds
Good with thin materials
Not practical outdoors (gas shield dissipates)
Requires clean surfaces (no rust or finishes)
Complicated (different wires for different materials)
2. TIG welding uses a tungsten electrode that, unlike MIG, does not melt. Instead, a separate filler rod is used, meaning both hands are in constant use. If you’re a professional who needs versatility, an artist, or you’re fastidious about finish, choose TIG.
Extremely precise, even welds that require no further finishing (preferred method of creative metalworkers)
Extremely strong welds
Steep learning curve
Not practical outdoors
Requires surfaces be completely free of dirt, rust, paint
3. Stick welding is the original form of arc welding, using a simple consumable electrode with a flux coating. This both melts the metal to be welded and simultaneously protects it with a gas shield. If you want to repair a rusty gate or oily tank and you don’t really care what it looks like, use stick welding. Also, a number of machines offer both TIG and stick welding functions, making them a very attractive all-round solution, though most are not cheap.
Can be used outdoors (and underwater)
Doesn’t require completely clean surfaces
Versatile (It can be used on aluminum and alloys, which very few MIG and only fairly expensive TIG machines can handle.)
High level of sparks/spatter
Large, scruffy welds
High consumption of electrodes
Inefficient (Any time saved from the welding process is lost through the need for extensive grinding and/or sanding to produce a reasonable finish.)
DID YOU KNOW?
The common types of arc welding are metal inert gas (MIG), also called gas metal arc welding (GMAW) or metal active gas (MAW); tungsten inert gas (TIG), also called gas tungsten arc welding (GTAW); and stick, also called shielded metal arc welding (SMAW).
ARC WELDER FEATURES
The higher the amps, the thicker the material a particular arc welder is capable of welding. You also need plenty of power to weld aluminum. Though it’s softer than steel, it requires a higher temperature. However, arc welders rated above 110 volts can’t be run from a normal household outlet. You either need to provide a separate circuit/breaker or, as some welders do, buy an appropriate generator.
Many arc welders are switchable between 110v and 220v, but don’t expect the same power output when running at the lower voltage.
There’s no direct correlation between a given number of amps and a particular thickness of material, so you need to look at the manufacturer’s ratings. We’d also suggest reviewing customer comments because these often give valuable feedback from real users.
Arc welders produce huge amounts of heat, and the units themselves get very hot. They all have cooling fans, but there’s a limit to how long an arc welder will run before it needs a break to cool down.
Manufacturers use the term “duty cycle,” which tells you is how much of a ten-minute period the machine will run at a particular current. This is a balancing act you often have to consider when buying an arc welder. A long duty cycle is only valuable if the machine produces sufficient current for your needs.
A 150-amp welder with a duty cycle of 60% will only run on full power for six minutes out of every ten. It then needs a four-minute rest. An arc welder with a similar specification but a 90% duty cycle will run for nine minutes.
A 200-amp welder with a 40% duty cycle might seem not to be performing as well as a 150-amp version, but it’s delivering a lot more power, so it’s capable of welding much thicker material, if for a shorter time.
Overload protection: This is a valuable inclusion that prevents damage if your welder does overheat.
Gun cable length should be long enough to give you plenty of freedom of movement. Ten feet is good. Some cheap arc welders have around five feet, which is a bit restrictive, though it’s usually relatively easy to find longer alternatives.
MIG welders should include a gas regulator.
We see warranties as an indication of a manufacturer’s confidence in the durability of its equipment. One year is an absolute minimum. It’s nice to have three years or longer, but it’s important to check just what is covered.
Arc welding temperatures can run from around 5,000°F to over 35,000°F (3,000°C to 20,000°C). Make sure you’re properly protected at all times.
ARC WELDER PRICES
Even most cheap arc welders are fairly well made, so a restricted budget shouldn’t stop you from getting a reliable machine. If you’re spending $150 to $200 on an entry-level arc welder, it will likely deliver sufficient performance for the hobbyist or occasional user, but it will lack the power for anything above 1/4-inch mild steel or the control to effectively weld a variety of materials.
With a budget of between $400 and $600, your choice is enormous. At this price point, you can more or less compose a wish list and find a welder that matches it, up to and including professional gear. You’ll find several welder/plasma cutter combinations, too. We estimate that most users will find what they need in this price bracket. However, while many offer switchable voltage between 110v and 220v, a 50-amp breaker is often required, and uprated wiring is recommended. Check power requirements before ordering.
At the high end, from $750 to $1,400, you get the power output to weld thicker materials plus the advanced control necessary for success with thin sheet or materials like aluminum, stainless steel, and cast iron. You’ll also frequently get a choice of AC or DC welding. Power demands almost invariably mean a dedicated supply is required. We suggest you employ the services of a qualified electrician for any work of this kind. Mistakes are both costly and dangerous.
Always wear a proper arc welding helmet. This is vital. The helmet is necessary to protect your face from burns, but it also protects your eyes from “flash burn” (also called “arc eye” or “welder’s flash”). It happens if you look at the intense UV light created at the point of the molten weld pool with the naked eye. It’s extremely uncomfortable and you’ll suffer eye irritation, headaches, and even temporary blindness.
Always wear welders gloves. They limit dexterity, but it’s better than getting burned by weld spatter (molten droplets that can fly off while working) which can be 5,000°F or hotter.
Always work in a well-ventilated area. A number of toxins are present in the gases given off. According to the Occupational Safety and Health Administration (OHSA) they present a serious health hazard. It’s a good idea to wear a basic respirator anyway, but if you have to weld in confined spaces, an air-fed welding helmet is strongly advised.
Although most arc welders offer some versatility, it pays to be as precise as possible when buying. Think about the type of welding you do most of the time and buy equipment that meets those requirements.
Q. Can I teach myself to weld?
A. You can, and many people do. Both stick and MIG welding are relatively easy, and there are a number of online videos that show different techniques. However, training with a professional is always a good idea. You’ll learn skills that will make sure your welding is strong enough to last. A number of courses are available, from part-time evening classes to full-time curriculums aimed at professional qualifications.
Q. What’s the difference between AC and DC welding?
A. Alternating current (AC) is nonlinear, and that fluctuation has both positive and negative effects. AC welding can be used on magnetic materials, while DC cannot. AC welding, which can penetrate deeper into the metal, is used for welding aluminum, which requires higher temperatures than most other metals. However, AC welding produces more spatter and usually leaves a rough surface that often requires further work.
Direct current (DC) is linear, which generally produces a smoother weld. The equipment usually costs less and is easier to master. There’s less chance of you burning through thin sheet than with AC. Standard electrical outlets provide AC, so an internal transformer is required to provide DC output, and this does make DC welders a little more expensive to run. However, they’re by far the more popular tool. Some professional-grade arc welders provide both current options.
Q. Is arc welding better than gas torch welding?
A. Done correctly, either one can produce a weld that’s as strong as the original material.
Gas torch (oxyacetylene) welding is very flexible. It can be used to cut, braze, or weld a variety of materials, but it’s a fairly “quick and dirty” method, best where appearance isn’t of great importance. Both MIG and TIG welding tend to give a smoother finish.
The equipment also has to be considered. Oxyacetylene welding requires two large tanks of extremely flammable gas (acetylene and oxygen, plus regulator, pipes, and torch. It’s not very portable. Arc welding units can be quite bulky, but they’re fairly self-contained: find a convenient power outlet, plug in, and go.