How to Select a MIG Welder

So you are ready to get serious about your metal work, and you want to add a wire feed welder to your shop’s arsenal. Good for you, a welder is one of the most useful pieces of shop equipment. Below, we take a look at the features and specifications you need to think about before deciding which one is right for you.

Flux Core VS MIG

Wire feed welders actually consist of 2 different welding types: Metal Inert Gas (MIG) and Flux Core. Flux core uses wire with a hollow core that releases a shielding gas as it melts. MIG uses a solid core wire and a tank of inert gas which shields the weld from contamination. Nearly every MIG machine can do flux core welding, but not every wire feed welder set up for flux core can be converted.

Eastwood Flux Core 90

Besides the lower cost, flux core welding does have other advantages. The flux does a better job of shielding in windy or dirty environments, so it’s great for field work. No gas and no tank – That means one less consumable to buy, and a smaller lighter unit to carry around if you take it to the job site or race track. Plus, flux core actually burns hotter, so it is actually better for welding thicker material.

There are several disadvantages of getting the lower cost, flux core only machine. First, flux core produces sloppy looking welds with lots of splatter, even in the hands of a pro. Second, because it burns hotter it is hard to weld thinner sheet metal without a lot of burn through.

So there's lots you can accomplish with just flux core wire, but, except for the lower initial purchase price, there is no reason to get just a flux core wire feed welder, when every MIG machine can do both. above you will see the suggested settings for the Eastwood MIG 135.  The bottom two lines of the top chart show the suggested settings if using Flux core wire.

Choosing a MIG Welder

MIG welding (Metal Inert Gas) takes the basic method of wire fed flux core welding, and uses a solid wire instead, plus a tank of gas which provides the shielding. Many basic flux core welding set ups can be converted to do MIG welding with just a few parts. Typically, you need to add a gas solenoid, a regulator, and a tank of shielding gas, though some already come equipped with the solenoid.

MIG works just like flux core: you pull the trigger, wire is fed, and gas comes out the tip to shield the weld. MIG welding produces cleaner, neater, more consistent welds, especially at lower heats on thinner metal. MIG is also the preferred way to weld aluminum, though you will need a special aluminum spool gun, and a tank of argon.

110v VS 220v

This choice may be dictated strictly by where you are planning on using it; if your shop isn’t wired for 220v, or you plan on using it on the go, 110v is the choice for you. But there are some welding units out there that run on either voltage, with just an adapter plug. This is a great compromise if you are planning on rewiring your shop in the future, or already have 220v in the shop, but want to be able to weld anywhere and everywhere.

The Eastwood MIG 135 is our entry level MIG welder.  It is perfect for the home user that wants a shielded welder but only has 110V power source.  This welder is rated to 3/16" which is perfect for auto body and basic structural repair.

Moving on to the next level is the Eastwood MIG 175.  This is a 220V only unit which means it will be able to weld thicker metal up to 5/16" steel.  You may think that there is not much difference between the two but the big difference is the duty cycle.  With the MIG 175 you will be able to weld on a higher setting for longer periods of time.

Lastly we offer the Eastwood MIG 250, this is a dual voltage unit and is internally controlled.  This means that you don't need to change any settings when going from 110V to 220V, just simply plug it into the desired power source and the welder will adjust accordingly.  On 220V this welder is rated to 1/2" steel, making it great for heavy structural welding.

But what are the advantages of the higher voltage? Obviously a higher voltage unit is more powerful than a lower voltage one; they typically can put out more heat and weld thicker materials. This is also important for welding aluminum, which requires more amperage compared to welding steel of the same thickness. If working with a lower amperage within the range of most 110v units, like 90 amps for instance, a 220v unit is going to have a much higher duty cycle. So, you’ll be able to get more done faster, with less down time.

Duty Cycle

The duty cycle for a welder is usually expressed as a percentage at a given amperage, 20% at 90 amps for instance. That is a typical rating for a home use 110v MIG welder, it means with the power set to 90 amps, you should only be welding continuously for 2 out of every 10 minutes to avoid overloading the welder. You could see how that would be an issue if you were building a bridge, or a tube famed chassis. A 220v machine is often rated at 30% at 135 amps, and something like 60% at a lower 90 amp setting. That means you can weld much longer without overheating the machine and having to take a rest.

Transformer VS Inverter

Years ago all MIG welders were transformer welders. They all used windings of wire to transform the 60hz AC voltage coming out of the wall into much higher voltage at the end of the welding torch, but still at 60hz. In the 21^st century, there are now welders that use solid state inverters to step up the wave frequency of the electricity to much more than 60 cycles per second. Because of this, they can produce higher voltages with much smaller transformers. Since transformers are just windings of copper wire, the smaller they can be, the more portable the welding unit can be. The inverter technology also allows machines like the Eastwood 200 Amp MIG/Stick to exist because they can switch internally to the different electrical requirements of flux core, MIG welding and stick welding, and produce different shaped waves if need be.

Inverter based units also need much less energy to run. If you are planning on running your welder off of a generator the inverter is the way to go. Transformer-based units require a much larger generator in order to work. The extra money you spend to move up to the inverter unit is money you will save by buying a smaller generator. The lower current draw of an inverter unit typically means you can run it on an extension cord for easier use around the shop. Your electric bill will be lower too.

Adjustability

Some machines these days can practically set themselves up, while on the low end some just have “high” or “low” heat settings. Like all things, if you can’t adjust it to suit you, you are going to have to adjust to suit it. MIG machines usually have 2 important settings: wire feed speed and power. Most times the more power you use the faster you want the wire to be fed, but not always. The more basic machines usually have fewer settings, and typically are “stepped” or “notched” meaning you can’t choose a setting between 1 and 2. The better machines are infinitely adjustable; you can choose any setting between anywhere on the dial, not just the numbers 1-10. If you can’t find a setting that works with the speed you want to weld on the material you are working with, then you have the change your speed to suit the output you can get. This is where the fine adjustments can come in handy.

Parts and Serviceability

A welder ought to be a lasting investment, but buy a unit from a low cost generic brand that hasn’t been around for long, and you may find parts and consumables impossible to find in a few years. At Eastwood we have been here since the late 1970s and we plan on being here a long time, standing behind our products. Not only do we have quality welding units at an attractive price, but we also carry all the parts and supplies you will ever need for them, except for the gas, but if it was possible we would sell that as well. We sell replacement tips, wire, torches and more for our MIG welders. We also have technical support for you by phone and email.

We are committed to providing professional quality welding machines at a price the home hobbyist can enjoy. You can buy more powerful welders from other brands, and you can buy less expensive welders, but we don’t think you will find a better welder for less.