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Choosing a Mig Welder

Wednesday, 18th March 2020

You’ve decided you want to buy a Mig Welder, but discovered there’s a bewildering choice out there. So how do you go about choosing a Mig Welder?

As not everyone is not a reader, I’ve also produced a video on this subject:

First things First

It may sound a bit obvious, but the first thing you should consider when choosing a Mig Welder is what you want to be able to do with it!

There’s little point in buying a 150amp Mig Welder because it runs off a 13amp plug if you want to weld 10mm thick sheet steel – it’s simply not powerful enough.

Conversely, there’s little point in spending big money on a 300 amp machine if you only want to repair stuff at home and/or restore a classic vehicle.

Choosing a Mig Welder

So power output and you own power supply are important considerations.

Broadly speaking, you can run a Transformer machine up to around 130 or 150amps (depending on machine), off a 13amp plug.

Inverter machines can be run at around 160amps off a 13amp supply. This is because an Inverter is more electrically efficient than a traditional transformer.

Having said all that, if you want to weld car body panel thickness material, the top end power is far less important than the bottom.

To weld car body panels you need a Mig Welder with a minimum output of no more than 30amps. A higher minimum output will result in lots of hole blowing in thin sheet!

So consider BOTH ends of the power range, not just the top!

The Basics of a Mig Welder

A Mig Welder can be broken down into two basic parts, a Power Supply and a Wire Drive System (inc Torch).

The Power Supply will either be a Transformer or Inverter (more about these later).

In my opinion, the more important consideration is the Wire Drive System, including the Torch.

I say this because after around 30 Years in welding, wire drive problems make up about 80% of the problems I’ve seen with Mig Welders. From DIY units to big Industrial units.

Duty Cycle

Another consideration regarding the power output of a Mig Welder is Duty Cycle. This is essentially how long the machine will run for before it overheats. If you want to do long welds at high power, a small DIY Mig is unlikely to be the right choice for you. But if it’s mostly small jobs, you shouldn’t have a problem.

I’ve written a separate blog article about Duty Cycle if you would like to know more. Ive also produced a video if you prefer to watch than read:

What to look for in a Mig Welders Wire Drive System

For me, when choosing a Mig Welder a decent sized Wire Drive Motor is very important. Many units, especially in the DIY market, have small, cotton reel sized motors that are only just powerful enough, assuming everything else is perfect.

Yeah, like everything’s always perfect, especially after a few Years use!!!

Next is the robustness of the Wire Feed Roller System. This is hard to qualify, but most practical people will know a good Roller System from a cheap crappy one when they look at it.

Mig Wire Feed

Mig Welder Torch

Lastly is the torch itself. A Steel Torch Liner is, in my opinion, VERY important. Many low cost machines have a plastic liner to cut cost. But this doesn’t last long when you’re feeding steel wire through it and changing the liner is usually a time consuming, fiddly job.

A plastic liner is also likely to be the No1 culprit of feed problems, and soon!!! So a torch with a steel liner is definitely worth looking out for!

A Steel Torch Liner looks like bicycle brake cable, a spiral of steel coated with plastic.

A really good thing to look out for is a Euro Torch. This Torch system has a Socket on the front of the Mig Welder and a Plug on the Torch.

The Torch simply screws onto the Socket with a Hand Nut.

Euro Torches are better quality, yet are nearly always cheaper than the permanently fitted type (should you ever need to replace the torch). This is because Euro Torches are standard on Industrial machines and so are made by the Millions.

Permanent fit torches are usually bespoke and so have to be bought from the machine manufacturer. This can mean BIG money!!

I would expect all Euro Torches to be fitted with a Steel Liner, ours certainly are!

Choosing a Mig Welder

Types of Mig Welder

There are two basic types of Mig Welder, which is mostly about the type of Power Unit inside the machine. When Choosing a Mig Welder, this is a pretty fundamental choice!

Transformer Mig Welders

Transformers are the traditional power unit for a Mig Welder. The advantages of a Transformer based unit are that they are usually cheaper and less complex, so theoretically more reliable long term.

The downsides of Transformers are that they are Heavy, Overheat more quickly and the power output is usually set in a range of steps. Transformer Mig Machines typically have between 2 and 30 steps. It is not possible to set a power output in-between these steps.

Inverter Mig Welders

Modern inverters are also far more reliable than units of only a few Years ago. Another advantage is that power output is steplessly adjusted, in other words, power can be adjusted in the same way you would adjust the volume of a radio, simply by rotating a knob.

Inverters are a modern, electronic unit for a Mig Welder. The advantages of an Inverter based unit is that they are lighter, so easier to move around and will run for much longer before overheating.

The only real, possible, downside with inverters is the complexity of an electronic board, which if it fails outside of warranty will need to be replaced. Replacement Inverter boards are not cheap as they typically represent over half the Mig Welders internal parts.


Which type of Mig Welder is right for you is a personal decision, because, as we’ve said, it all depends what you want to be able to achieve.

Visit our Mig Welders Page to view our current range.

Need to Know More?

If you need help and advice with choosing a Mig Welder, please don’t hesitate to get in touch. Either via the Contact Us page of our website, or by picking up the phone for an informal chat, ask for me!

I hope you found this article useful.

Please let me know what you thought of this article by leaving a comment.  

Don’t worry, your email address won’t be added to a database or shared and you won’t receive any unsolicited email.



The Welders Warehouse


  1. Bob Cooper says:

    The PCB in My Draper DTI 140 failed after 6 months of light use and Draper utterly refuse to honour any warranty saying it’s my fault due to using a 13 amp plug and not a 16amp. It was scrapped. Who makes a decent inverter welder with a proper warranty?

    1. Graham says:

      Hi Bob
      I regret I’m not 100% sure what the Dti 140 is, but Drapers website shows a Dti 160 which is a multi process Mig Welder. If that’s what yours is, then our iMig 160 Synergic might be a good fit for you. It does run off a 13amp Plug (plug is fitted).
      Extension Leads are something to be wary of. A lot of the DIY stores sell “13 amp” leads that are up to 20M long but are only made form 1.5mm² cable (that’s the cross sectional area of each of the 3 wires). For high draw items like welders you need a heavy duty extension lead, I would suggest AT LEAST 2.5mm² Cable. Cable size is usually stated somewhere in the small print on the packaging, but the cable is noticeably heavier.
      Hope that helps

  2. Jim says:

    Hi Graham, Thanks man I’m learning a lot. Just one question, are these mig welders will work with my garage wall outlet rated 15 amp?

    1. Graham says:

      Hi Jim, Thanks for the comment and question, good to hear you’re finding the blog useful.
      You haven’t specified which machine you would want to use from a 15amp socket, so i can’t really answer the question. The website does state the Max draw in amps that each machine would require to operate at Max output, this is either within the “Description” tab, or the “Spec” tab.
      Hope that helps (a bit :-).
      Cheers Graham


    Hi Graham, I purchased a BlueMig140T in July 2017, spookliy, like a previous comment, I too have misplaced my Manual/user guide. Can you email me a copy please. Also I have a problem with the wire drive, the relay operates but does not turn the drive motor(there is no blockage and the wire pulls through very freely)Can you include a wiring diagram too?

    1. Graham says:

      Hi Stephen
      I’ve emailed a copy of the manual along with some instructions on a fix for the most likely cause of the wire drive motor issue.
      Hope I’ve helped.

  4. stephen holford says:

    hi graham a few years ago i bought a bluemig 140t from you ,i have managed to misplace the instruction booklet that came with it can you email it to me please

    1. Graham says:

      Hi Stephen
      No problem, a copy has been emailed.
      Kind Regards

  5. John Holland says:

    What an excellent, helpful and informative resource. I was going to purchase a Clarke welder from the internet but will now call Welders Warehouse !

    1. Graham says:

      Thanks for the kind and generous comments John, much appreciated. Good to hear you found our website useful.
      Worth pointing out that we offer full phone support of all our products, including Mig Welders.
      Best regards

  6. Mike Smith says:

    Hi Graham
    I am a novice and would like to learn to weld as I wish to build my own smoker and a couple of other items . Any advice on which type of welder to go for.
    Many thanks in advance Mike Smith.

    1. Graham says:

      Hi Mike
      Mig is probably the easiest process to learn. Provided your project doesn’t have steel thicker than 6mm, you should be OK off a UK 13amp supply. Alternative would be an Arc (stick) welder. These can be more versatile, but require more skill to use.
      Call e if you would like an informal chat about your projects and choosing a machine.
      Hope that helps

  7. colin says:

    HI Im looking for recommendations for a welder
    it would be used for agricultural spec repairs and fabrication. Ive been using an old sealey supermig 220 for years now whichhas been fairly reliable but does overhaet quite quickly on heavier jobs .

    1. Graham says:

      Hi Colin
      Thanks for the question.
      The Cros-Arc 201C is a very popular choice for agricultural workshops.
      The Duty Cycle is significantly higher than your Sealey and it’s single phase.
      I’ve also written a blog article on Duty Cycle if you need to know more about that.
      Call or email if you need any further info.
      Hope I’ve helped.

  8. Joseph Crossan says:

    Hi, What do you think of the omni pro 220 or titanium 200.0

    1. Graham says:

      Hi Joseph
      I regret I have no knowledge of the machines you mention, I don’t think they’re sold in the UK. There are YouTube video demos etc of the Titanium 200. Deal maker/breaker for me would be warranty length and support. There are LOADS of crappy machines coming out of China and spotting them among the good ones can be a challenge. Warranty and Support are two good indicators, if a PROPER WELDING EQUIPMENT SUPPLIER is offering a machine, with 2+ Year warranty, it’s bound to be a good one. If it’s a John Doe seller of everything offering a shorter warranty and they know little about welding LEAVE IT ON THE SHELF!!!
      Hope I’ve helped, at least a little bit 🙂
      Cheers Graham

  9. Helen says:

    Hi there
    Is the BlueMig 150 a transformer or inverter based welder?

    1. Graham says:

      Hi Helen
      Thanks for the question and sorry for the slow reply.
      BlueMig 150T is a Transformer based machine.
      Hope I’ve helped.
      Kind regards Graham

  10. Russell Thompson says:

    Excellent article for myself, basically a mechanic and not a welder. I say excellent because it was easy to understand, concise and thorough enough that I feel I am ready to start researching for purchase. I must say that I read a lot of articles like this and less than 1% are written this good. Thank you for saving me so much time and need to scan inferior material.

    1. Graham says:

      Hi Russell
      Apologies for the slow response and Thank You for your generous comments. There are a LOT of box shifters out there, so we try to make ourselves different by supporting our customers both pre and post sale. Good to know its appreciated.

  11. Kevin Laycock says:

    Hi thanks for the info
    I am looking for a gas mug welder for general maintenance use on mild steel ( 0.8mm to 6mms and stainless 0.8mms to 2mms with a euro torch running of a 23A 240v supply
    Any machines I should look at or avoid

    1. Graham says:

      Hi Kevin
      Apologies for the slow response to your comment.
      The SWP Stealth 200 would be a great choice. Please feel free to call if you would like an informal chat about your needs.

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