Best MIG Welder for Shipping Container Home Construction

Here we are project builders, about to embark on this magnificent build of turning an old shipping container into a living space.  Whether you’re building a single container shed, micro-home, or designing a large scale multi-level build involving multiple shipping containers, you will have to content with one common element; Cor-Ten Steel.  Don’t let the “Cor-Ten” designation scare you, it’s just steel that has been treated to resist corrosion.  It’s the steel part of the name that you will be dealing with.

Conventional wood buildings involve conventional tools.  Tools you probably already have in your garage like saws and hammers.  But when you build on a shipping container, everything you add or take away from the structure will involve a new class of tools with a more industrial flair.  Angle grinders and welders.  Securing one small piece of metal to another can be done with screws or bolts, but that won’t work on the grand scale we’re working on with shipping containers.

From mounting your container to its foundation, to the doors and windows, to the roof, and every element in between, you will be securing everything to the steel structure of your shipping container.  This means one of two things to you as your build begins; either you are good at welding, or you will become good at welding.  By the time you finally pack away the tools and move into your new shipping container home, you will have mastered the art of welding.

In theory, welding is nothing more than melting two pieces of metal together and making them one.  In practice, it’s more of an art.  There is no doubt about it, your first welds will be terrible and ugly.  You’re going to get in plenty of trial and error so make sure you start out on some scrap pieces and get the hang of, begin your build with some of the recessed and hidden welds before finally moving on to the welds that will be visible.  By the end, your welds should be clean and even, a skill to behold!

A standard forty foot shipping container consists of roughly 8500 pounds of steel, you will have plenty of experience welding steel by the time you finish the build.  Before we dive in with buying the right welder for working on your shipping container, it is worth noting that safety should be your first concern in all construction projects, but the DIY welder working on a shipping container conversion carries a few concerns.

Ventilation is critical.  As we will explore, the magic in welding happens in a gas bubble.  You will need to make sure that you have fresh air coming in to replace all these gasses you are creating.  Also, some of these containers were built or modified in countries across the globe.  It is possible you’re still working with contaminants like led-based paint and other dangers.  So as we begin checking out the right welder for you, make sure whichever welder you eventually get, you need to stay safe while using it.

If you have a lot of welding experience, you likely already have a welder or know which one you like to work with, so we’re assuming your exposure to welding may minimal.  Not everyone picks this up as a hobby or weekend garage job so if you are intimidated, you can relax, it’s not as confusing or difficult as it appears.  First we’ll explain the types of welders available and tell you why the MIG welder is likely the best option for working on your shipping container home construction.

The melting of the metal and re-bonding together happens in a small gas bubble.  Sometimes this gas in the form of a flux that coats the continuous feed of wire while you’re welding.  This is a great option for small welding projects as it doesn’t require the additional cost or transportation of gas cylinders.  However, this small gas bubble is prone to being whisked away by the wind of you are working outdoors.  Conventional welders have an inert gas like CO2 that encapsulates the weld.

The welding medium is also open to options.  Stick welders are common in industrial work sites and they have you feed in the welding rod as you melt the metal.  Other welders have a continuous feed that pushes the electrode wire into the weld from a large spool so you don’t have to stop to grab new welding rods.

The TIG welder is a Tungsten electrode welder that requires training and practice before you can master the weld.  With a MIG welder, it is a little messier with some spalling and spatter from the spent electrode, but can be learned and ultimately mastered before you’re finished converting this shipping container into a living space.

The MIG welder is more than capable of creating the weld bonds necessary for the conversion of the shipping container into a home.  For that reason, with it being a simpler machine and easier to use, we suggest that a MIG welder is the best option for tackling this project.

Now that we’ve covered the basics of how a welder works, and we’ve decided that a MIG welder is preferable because it creates a strong bond while remaining user-friendly, here are the various aspects of what to look for in your new MIG welder.

Input voltage

This may seem obvious, but not every tool can be plugged into your standard house wall outlet.  Since we’ve already established we’re approaching this guide with the assumption that we’re relatively new to the world of welding, you may not be aware of how much power these things can pull and that the more powerful the welder, the more voltage it requires to feed it.

The beefier models require 220VAC.  That’s what your household clothes dryer or stove top uses.  If you opt for the larger welder you’ll need to be prepared to plug it into a 220V outlet.  Smaller welders use standard 110VAC and can be plugged into a standard household wall outlet.  But beware, just because it plugs in does not mean it will work flawlessly.  These welders pull a lot of amperage and if you plug it into a circuit that already has lots of other appliances on it you could blow a breaker.  It’s a safe bet to plug this into a dedicated outlet or garage outlet set aside with nothing else pulling amperage from the circuit.

If you’re converting your shipping container out in the wilderness or even just out and away from the conventional power grid, access to power can be limited and you may need to take that into consideration before purchasing the welder.

Material capability

Not every welder has the same capabilities as the rest of them.  Some welders can weld various types of metals such as steel, alloyed steel such as stainless-steel, and aluminum.  A standard steel welder should be all you need to get your shipping container work done as there isn’t much stainless steel or aluminum involved in their construction.  Should you decide you need a machine to weld aluminum and other such materials, larger welder machines are available.

Amp range

Most welders come with an adjustable amperage output meaning you can control how powerful the machine welds.  The higher the amperage, the hotter the weld contact point.  This is important as you’ll need to adjust the amperage depending on the thickness of the material you’re attempting to weld and the length of the weld bead you’re running.  Too hot and you’ll burn through thinner metals, too cold and you won’t be able to weld the thicker metals.  Dial-in controls give you the power to adjust according to your task.  The walls of your shipping container are most likely the ISO Container Standard 14 gauge, thick enough for strength and thin enough to we altered by nearly any welder on the market.

Metal depth

Depending on the voltage input, the amperage output and the set up of the welder, it will be capable of welding various thickness of metals.  A standard shipping container conforms to ISO Shipping Container standards.  The walls are 14 gauge and the corner posts are made from 1/4” steel.  The thing to remember when you’re reading about material thicknesses and you read about gauge steel, the smaller the number, the thicker the metal.  The 14 gauge walls measure out to be roughly 1/16” thick.  The 1/4” corner posts would equate to roughly gauge at 2.

Now that we’ve established what to look for in a MIG welder, let’s take a look as some diverse models to give you an example of what is available and which machine may suit your needs.

  • Longevity MIGweld 140

This model welder has “DIY” emblazoned right on its side because it knows it is the welder of choice for the weekend repairman or those tackling the conversion of large steel boxes.  Operating on standard 110VAC house power, you can run this welder with no preparation outside of a hefty extension cord.

The face of the machine has dual dials controlling the welding amperage up to 140A, enough to weld 3/8” steel which is thicker than anything you will encounter on your shipping container build.  The other dial controls the speed of the wire feed allowing you to hone your welding craft and slow/speed the feed to suit your skill.

The Longevity MIGweld 140 is a “beginner” welder but it is capable of welding our container steel and the convenience of standard power makes this an excellent choice.

  • Lotos MIG140

Another 110VAC welder, the Lotos Technologies MIG140 is comparable to the Longevity model except for a few nice bells and whistles.  For just a slight increase in cost, you get some worthy additions.

Digital readouts on the Amp regulator and the wire spool feeder are a beneficial addition that takes the guesswork out of getting to know your welder.  The dial will tell you all you need to know once you experience how the welder responds, but a number readout may help you familiarize with the tool.

The other worthy addition is the “2T/4T” switch.  This allows you to handily switch between two-touch welding and four-touch welding.  Using a foot pedal to control the flow may help with your coordination but it may be impractical when you’re welding in awkward positions where you may not have full and free motion of your feet.

The Lotos MIG140 is an excellent welder for the consumer that is looking to take their welding skills beyond what they need for shipping container work.

  • Mophorn MIG Welder 200

Stepping away from the 110VAC models, the Mophorn MIG Welder 200 runs on 220VAC.  It takes that AC power and runs it through an internal inverter and produces 200VDC which powers the welding arc.  The result of the inverter power is a cleaner burn with less spatter.

Also contributing to less spatter is the voltage pulsation compensator.  This accounts for minor fluctuations in the input voltage, possible regulated simply by converting AC to DC and conditioning the power, results in fewer surges and pulses and results in a much cleaner weld that requires minimal cleanup work.  Cleaner welds make for prettier shipping containers and after all, you will be living in your own work results, you want it to look as good as it can.

  • Hitbox MIG200

The Hitbox MIG200 is another 220VAC model that will require you to have a 220V power source to run this welder.  The inverter technology will ensure the power fluctuation is kept to a minimum and as such, these inverter MIGs are capable of being run of of a powerful enough generator so even when working on your shipping container conversion out and away from the closest power outlet, you can rely on a clean weld due to the capacitor-like inverter.

The face of this Hitbox MIG200 has the amperage dial and the voltage/amperage digital displays but it also has a few helpful pushbuttons as well.  This model can operate as an ARC welder and a Lift TIG welder in addition to the MIG function.  You also have the option of selecting solid core wire for your gas accompaniment and Flux-core wire for when you do not.  This welder is capable of much more beyond the rather simple work of steel container conversion and if you are looking for a more well-rounded welder for your future work, this may be the tool of choice for you.

  • Hobart 500536 Ironman 230

If money is no object, we’ll add in the Hobart 500536 Ironman to the list.  Remember when you wrote out your Christmas list and you always had the big gift up top but knew you wouldn’t get it so you listed all the reasonable gifts underneath?  Well the Hobart 500536 is the “pony” at the top of the list.  For a similar cost that could net you an additional shipping container, this monster of a MIG welder is professional grade in the consumer market.  Amp rating between 30 and 250, you can weld as small as a half millimeter all the way up to solid 1/2”.

The Hobart is large, expensive and more than you need for anything you’re working on with the conversion of a shipping container.  But if you’ve got the funds, this Cadillac of a welder will more than handle anything you may need short of industrial or military bonding.