by Perfect Welders

What About Multi Process Welders？Are Multi Process Welders Worth It?

Welding is a fabrication process used to join two or more parts using heat and pressure. Welders use this process to form new products or to make repairs to existing structures.

There are many tools that can be used when performing welds. This includes the machine used for the job itself, which will differ depending on the type of welding process being used. One tool that you might consider investing in if you’re performing welds is a multi-process welder, which is capable of performing a range of weld types.

Keep reading to learn more about what a multi-process welder can do and what to expect from this machine.

How a Multi-Process Welder Works

A multi-process, or MP, the welder is a piece of equipment that can be a useful part of a welder’s tool kit. A multi-process welder is able to perform two or more welding processes.

This is possible by changing polarities (positive, negative or even AC) and adjusting the process selector, going from SMAW to GMAW, for example. These multi-process welders offer the ability to weld a high variety of metals using different welding processes, allowing the person welding to switch methods in just a few minutes.

What Are Multi-Process Welders Good For?

Arc welding is the most common process used in welding applications. Arc welding processes utilize an electric arc to fuse metals together, forming new shapes and objects. Heat generated during arc welding processes can reach around 6,500 degrees Fahrenheit.

A power source is used to create an arc between an electrode and the base material, which melts them at the point of contact and creates a welding circuit. A multi-process welder is often designed to perform two or more of the main four arc welding types. These include:

Gas metal arc welding (GMAW): Also known as metal inert gas (MIG) welding, this method uses constant voltage equipment to create heat by carrying current between a continuous solid wire electrode sent through the welding gun and accompanied by a shielding gas.
Shielded metal arc welding (SMAW): SMAW welds are also referred to as stick welds. This method uses constant current equipment that creates heat from a direct or alternating current that is sent between the flux-coated electrode and the workpiece.
Flux-cored arc welding (FCAW): Flux-cored arc welding creates heat from a direct current electric arc and uses constant voltage equipment in the process. It carries current between a continuous hollow wire with a flux compound and can be done with or without shielding gas.
Gas tungsten arc welding (GTAW): Also known as TIG welding, this method utilizes constant current equipment to create heat from an alternating or direct current electric arc. The current is carried by a tungsten electrode accompanied by a shielding gas.

Typically, multi-process welders are good options for maximizing what you can do for the price. While they are more expensive up front than welding machines that perform only one type of weld, they save money in the long run because they can perform many different welds.

MP welders are great for applications that require working on pieces that have various thicknesses, different types of welding joints, indoor and outdoor applications, or multiple base-metal types.

The benefit comes from being able to easily switch from one welding process to another, which adds to productivity and uninterrupted workflow.

When to Avoid Multi-Process Welders

There are some circumstances where using a multi-process welder might not be appropriate, and it’s important to keep these in mind.

If only one of the welding processes is needed, it doesn’t make sense to spend money on a tool that will give you multiple options. Saving money for a higher quality welding machine for a particular type of process would be the smart thing in this case.

It’s also good to keep in mind that MP welders will likely perform certain welds better than others. Depending on the type of welds you perform most often, this is another case where it might make sense to buy one machine.

The “one tool that does everything” is kind of like the Holy Grail for anyone that likes to make stuff. This is probably why multi-process welders are so intriguing. Can they really do it all? Are they worth it?

Multi-process welders can be totally worth it for home hobbyists or those that do small amounts of welding. For industrial applications or when welding is a critical aspect of what you do, you’ll want to stay away from them.

The issue of what tool is right for the job always comes down to a single question:

What are you going to use it for?

In this post, I’ll share some information that can help you to make a good decision for what you do, and I’ll help you understand what you can expect out of one of these machines. I’ll also share some buyer’s tips to help you pick one out.

What Multi Process Welders are Good For

Multi-process welders are a great option for your garage if you want to have the ability to do a few different types of welding operations at a reasonable price point. Although they’re generally more expensive than a single-process welder, they’re also much cheaper than buying multiple welders that each do one function.

Most multi-process welders (MPs) can do two or more of the following processes:

TIG
MIG
Flux-core wire
Arc
Plasma cutting

I should just mention here, that just because a welder can do two of these functions, that doesn’t necessarily mean that it’s classed as “multi-function”. For example, my Lincoln 225 TIG welder can also do stick welding, but it’s very much a TIG welder. The stick welding is more of an afterthought since it’s such a basic function.

Also, MIG welders that can also do flux core are kind of the standard, too. If it can do MIG welding, it has everything it needs to run gasless as well. It kind of goes without saying, so it’s not really considered a multi-process welder either.

Generally, MP welders are 110v/220v smaller machines that are for lighter-duty applications, like welding up to 3/8″ thick steel plate or so. They’ll do some varied combinations of processes, like TIG and MIG. For the home hobbyist, that’s generally more than enough. For industrial shops, probably not.

So the benefits seem pretty obvious for multi-process welders. If you want to do a few of these operations, an MP welder seems like a good choice.

Where Multi-Process Welders Don’t Make Sense

MP welders generally don’t make sense if you’re not regularly going to use more than one of the functions. For example, it’s not really worth spending more for TIG welding if you’re really only going to be using flux-core arc welding. You’re better off spending your money on a better quality flux core or MIG welder.

Another rule of thumb is that a jack of all trades is a master of none. For all multi-process welders, it’ll do some functions better than others. For example, it might do great as a MIG welder but lacks finesse/functionality as a TIG. This may or may not be important to you.

It also doesn’t make sense if you really rely on the welding machine and need, let’s say, two of the functions. For example, if you’re running a small welding business, and you only have one welder, and your inverter dies, everything grinds to a halt.

That said, it’s never good to be critically dependent on one single machine if your livelihood depends on it.

You’re best off just getting two machines that do what they’re intended for and have them work reliably. They’ll perform better, too. It’s next to impossible to simply read reviews and understand not only what the machine does well, but where it’s weak. There are a large number of first-timers writing rave reviews on multi-process welders that wouldn’t know a good TIG weld if it bit them in the… somewhere.

What Nobody Tells You About Multi-Process Welders

There’s one main thing that generally goes unnoticed when people are looking into a multi-process welder for the first time.

The gases for each type of welding are different.

For plasma cutting, you’ll probably use just regular shop air. For TIG welding, you’ll use an inert gas like argon or an argon/helium mix. For MIG welding, you’ll probably use CO2. For stick welding, you’ll just breathe the fumes instead.

The point is, even if your machine is capable of doing 4 different processes, getting all the gases ready and available can be an expensive hassle.

The only really convenient way around it is to set up for TIG welding (pure argon or 75% argon/25% helium mix) and then use flux-core arc welding and/or stick welding.

That way, you don’t need to buy or rent expensive bottles and you don’t have to worry about changeovers aside from the electrode holder/gun.

Even still, you’re limiting yourself and usually not really getting as much as the sales page lets you believe. You’re probably not going to want to properly set up for both TIG and MIG with a multi-process welder. If that’s what you need, you’re best off not having to constantly swap out bottles and just get one of each machine.

Hopefully, so far you’ve been able to narrow down whether or not a multi-process welder is right for you. Now here are some buying tips.

How to Pick the Right Multi-Process Welder

Some of these are general-purpose tips for buying any kind of welder, and some of them are specific to MP’s.

Off-Brand = Less Amps

Now I’m not saying that the only welders that actually put out the rated amps are Lincoln, Miller, Hobart, and the small handful of other brand names.

However, if you’re eyeing up a super cheap multi-process on Amazon, just be aware that the output amp rating is much different from what is actually output. Sometimes, you’ll only get half of what’s advertised once you check it with a multimeter.

That’s one of the reasons that many choose to spend more on a recognizable name. If it says 200 amps for TIG welding 5/16″ steel, you’ll actually be able to weld 5/16″ steel.

For the off-brand super cheap ones, you’ll probably either blow up the machine or just never get proper penetration if you try to run it at max amps.

Just Because it Can TIG Doesn’t Mean You Can Weld Aluminum

For a lot of the MP machines out there, TIG is only offered on DC, not AC. This means that it’s not well suited for aluminum.

Alternating Current has a cleaning effect on aluminum, and it’s much needed. Aluminum oxides will mess up your weld pool and ultimately make your welds break if you run DC.

Dual Voltage has Downsides

A lot of the multi-process welders that attract hobbyists and small shops are dual voltage. Obviously, it’s nice to be able to plug a welder into any outlet and go to town.

However, it’s worth knowing that you can’t weld as thick of metal on 110V as you can on 240V. So, while it’s convenient, you should at least be aware that you might not be able to weld what’s advertised unless you’re on 240V.

Pay Attention to Duty Cycle!!!

This is important, and lots of hobbyists don’t know what this means.

Duty cycle is how long the machine can run continuously based on a 10-minute period.

So if a machine has a duty cycle of 30% at 100 amps, you can run it for 3 minutes, then let it cool down for 7 minutes. If you’re running at a lower amperage than the rating, you can run continuously for longer.

What happens when you exceed the duty cycle?

Ideally, the machine will just switch off and stay off until it cools down. It’ll have a thermocouple in there somewhere that tells it to take a break.

But if you keep maxing it out like that, you might end up with an aroma of burning plastic, and possibly even a burnt-out machine. Just be aware of how long you’re welding continuously, let the machine take breaks, and you’ll be fine.

Multi-Process Welder Recommendations

This could be a never-ending list of everything that’s out there, but I’m going to keep this really simple. Feel free to do your own research to pick out the one that’s just right for you, but here are some popular (for good reason) machines, along with what they can/can’t do.

Cheap, does a few things OK but nothing wonderful:

You can buy these multi-process welders from Perfect Power Welders on Amazon that are OK for hobbyists, but it’s hard to argue with the price being so low. No MIG/flux core, but as a plasma cutter, very basic DC TIG (no aluminum) and arc welder, you can do a lot for cheap.

The “very basic TIG” means that you’ll probably want to spend a bit more at some point on a few more accessories, like a foot pedal. Even still, you won’t be able to compete with the pros that can drop dimes on every pass.

The one cost to factor in is for a bottle of argon. It’s worth calling your local weld supply shop first just to know what to expect price-wise before committing.

If you just want something to handle miscellaneous jobs that come up in your garage, then this is probably exactly what you’re looking for.