MIG welding Advantages and Disadvantages

MIG welding is arguably the easiest of the arc welding processes for a novice welder – and one of the most versatile for a skilled professional, whether you're working in automotive chassis construction or container fabrication. But what are the headline advantages and disadvantages of MIG welding. Grab a coffee, break open your biscuits of choice, and take a few minutes to read the R-Tech take on what MIG is good – and not so good – for.

Since its introduction in the Californian aerospace industry in the 1940s, MIG welding has grown and grown in popularity. As well as the technique’s suitability for metals such s aluminium and magnesium, this is largely due to MIG welding’s speed and relative ease. Which leads us perfectly into the first of MIG welding's advantages.
 

The advantages of MIG welding

MIG welding is fast

With any welding, the time taken has to reflect the difficulty of the join and the quality desired from the finished weld. But, all things being equal, if you put MIG welding up against the other popular forms of welding, MIG is going to win most if the time – whether in the hands of a welding novice or a seasoned fabrication specialist. Why? The answer lies primarily in the continuously-fed electrode, which may be fed from the welding machine, from a spool-gun MIG torch, or in sophisticated industrial applications, through a combination of push and pull feed technology.

Ease of use

One day, we’ll find out just how easy MIG welding is for a complete novice when we set our copywriter loose on some gash plate with one of our machines. He had a go at oxyfuel welding about 40 years ago, so if anyone counts as a novice, it’s probably Al. Watch out for the video and blog post in future…

But seriously, the one-handed operation of the MIG torch and the automation of several other aspects, make MIG welding easier to learn and gain proficiency with than, say, TIG welding or stick welding.

MIG weld quality

Put simply, all things being equal, MIG welding allows you to quickly make very high-quality welds – often faster than other welding techniques. As we’ll mention again later, MIG is flux-free, so there’s no chance of entrapping slag in the weld. Result? Great welds and fast…

Long-pass welding

Here’s another reason why MIG scores for speed. You’re able to deposit more weld metal with each pass of the MIG torch. Maybe that’s less of an advantage on a small weld, but when you have a long, complex weld to make, you can get the job done with fewer passes – which saves time, helps you work more efficiently and (if you’re a welding professional) helps you work more profitably. That’s definitely good.

Penetration matters

Of course it does, and with MIG you can get great penetration (the depth of your weld) and be sure of a strong, smooth, bead. Best of all, you can achieve this on a wide range of metals with differing thicknesses. Aluminium? No problem. Mild steel? A cinch? Magnesium? No worries. All you have to do is get your head around setting the correct current (Amperage) for the wire and the metal and great penetration will follow.

Fewer stops and starts

That continuously-fed MIG electrode scores again when it comes to cutting down the number of times you have to stop and start welding during a job. With stick welding, or even TIG, you’ll be stopping and starting as if you are in rush-hour traffic. What’s more, there will inevitably be adjustments to make and new electrodes to fit before you can re-start that weld. Just like the difference between trying to get to a job at peak time and making the same journey early in the morning, it all adds up. Try it and you’ll see what we mean.

Electrode stub loss? What’s that?

If you’ve ever tried stick welding, you’ll know that no matter how skilled you are, you end up wasting several centimetres of each welding stick. It’s called stub loss, but it’s a term you can banish from your welding vocabulary with MIG welding. That’s because you can use all your continuously-fed electrode. That’s more time and money saved!

MIG works with many metals or alloys

It’s true. Remember how MIG was originally developed for aluminium and magnesium alloys used in Californian aircraft factories? That same versatility means that MIG works a treat with alloys, stainless steel, aluminium and mild steel alike. A wide range of filler materials means increased precision when matching filler to the workpiece metal or alloy.

MIG welding is clean

Okay, so maybe TIG welding is the ‘King of Clean’ when it comes to electric arc welding, but MIG isn’t that far behind and it makes traditional stick welding look positively ‘scuzzy’.

It’s true. Unlike stick welding, which is renowned for the flux involved and the amount of slag generated, MIG welding is really rather mess-free. Because there’s no flux, you can’t trap slag in your weld – it’s another key to those high-quality welds we mentioned earlier.

What’s more, because you’ve got that protective gas shield (typically argon or an argon mix), there’s minimal loss of alloying elements – and the tiniest amount of weld spattering.

That’s good, right? Less clean-up time, neater jobs, faster, and more productivity. Result!

If you’re a seasoned MIG welding pro, none of this will surprise you. But if you’re a welding newbie, it should be reassuring. But surely there’s a catch? There’s always a catch, right?

Okay, like most things in life, there are two sides to MIG and we’d be remiss if we didn’t flag up the known limitations of this welding method. 

Disadvantages of MIG welding

Compared to stick welding, a basic MIG welding set up will cost you more, so it’s arguable that MIG welding is more expensive to get into.

MIG welding costs more (to set up)

The thing is, that a good MIG welding machine will last you years and years; and if it’s designed for repair and maintenance at component level you won’t end up having to replace the whole machine after a few years when all you need is a new part. So, a good MIG welding machine is an investment. And there’s more, because with many modern machines, you can do stick welding (maybe even TIG welding too) with the same machine. That gives you welding power that sticks can never give you – and opens up more opportunities as you develop your skills. By the way, if you haven’t looked recently, you should check out the spec of a MIG welding machine that you can invest in for just a few hundred pounds like our R-Tech MIG 180 MIG Welder. Prepare to be impressed and amazed. You can get a lot of machine for the price of a long weekend away… 

More maintenance?

Okay, a MIG welding machine is more complex than a stick-welding set up and regular maintenance is importance, for safety and quality of welding. But remember again our point about component-level repair and maintenance. Not all machines allow this (R-Tech MIG welders do), but many do. As well as that, if you choose right, your welding machine supplier will lend you a MIG welder while yours is in for a service. We do! Why wouldn’t you?

The wind problem

Not that kind of wind problem, but the effect of draughts or wind gusts on the shielding gas flow if your workshop is badly sealed or you are trying to work in the middle of a field. Okay, hands-up, it can be an issue. But decent welding screens are easy to construct – or buy off the shelf  – and they will make a big difference in all but serious gale-force conditions. It’s something to be aware of, but it’s not insurmountable…

Portability

Traditionally, MIG welding has lost points due to the lack of portability of MIG welding machines. There’s truth in this; your average MIG welder isn’t the most portable bit of kit you’ll own. But modern machines are remarkably portable. Take the R-Tech 180 Amp Portable Inverter MIG Welder (240v), which weighs in at 330 x 210 x410 mm. Even with a generator (we can help there too) and gas, we’re sure you’ll agree that’s pretty compact… Unless you are out on the road day-in-day-out, maybe portability isn’t the big MIG welding disadvantage that it’s made out to be.

The other thing that is sometimes tied-in with portability is the size of your typical Euro MIG torch. Maybe in the trickiest, tightest, corners if you’re trying to do a complicated weld, a MIG torch might be a little cumbersome. But most of the time? We think not. You should try one of the latest MIG torches yourself to see…

Weird positions

If that tricky weld happens to include vertical or overhead welding, the high heat input and mobility of the weld puddle may mean that you need to look at another welding technique. But that’s a small price to pay for all the advantages of MIG welding. Besides, if you choose the right machine, you’ll have stick-welding capability anyway. Problem solved!

Burn-through

With certain materials, not least aluminium, there is a risk of burn-through if your workpiece is less than .5mm. Up to a point, your skill level may help you get around this, but it's generally accepted that MIG isn’t best suited to very thin materials.

So there you have it. The pros (many) and cons (a few, and often surmountable) of MIG welding in the time it takes to down that coffee and polish off a few (is half-a-packet a few) biscuits.

If you’re in the market for a new MIG welder, check out our collection here at R-Tech, or if you fancy getting some free advice on what machine spec is best suited to your needs, give our technical team a call for free on 01452 733933. They’d be more than happy to offer their advice!