MIG welding is a growing trade and practice. Using a top-notch MIG welder over other types of welders can often be preferable when looking for versatility and ease of use. It can, however, be a daunting task to get the right setting into your machine for the specific project you are working on. There are many variables to take into account. Let’s discuss the basics of MIG welder settings and get you on your way to being a pro!
The Correct Parameters for Optimal Performance
1. Voltage and Polarity
MIG welding requires the polarity to be DCEP. This reverses standard polarity. This will always be the polarity setting you should use.
Voltage is really just how hot you want the arc to be. The higher the voltage setting, the hotter it is. If you’re welding thin or weak metal you don’t want your voltage too high or you risk burning through the metal. If you’re welding thick or dense metals a higher heat is optimal to ensure the weld is strong and bonds well. The MIG welding machine itself will come with a guide chart that should show you the general pre-sets you want to apply with regards to voltage, based on what kind of metal you are welding, what kind of wire and gas you are using, and a number of other factors. You, however, need to tweak these settings to be more specific as you go along by way of trial and error. A few test welds may go a long way in finding the perfect voltage setting for the specific project you are taking on.
2. Wire Speed Setting
You need to set the speed that the wire is fed through the welding gun. Most welding machines will have a pre-set that matches your voltage and amperage settings. But if not, you will need to test weld to figure out the perfect speed. If the wire is fed faster than it is being melted it is obviously going to be counter-productive and mess up your work forcing you to stop and re-weld. If the wire is not being fed fast enough, it will burn down to the contact tip; forcing you to replace it and start again. Try a test weld and observe if the wire is feeding and melting at a balanced rate and maintaining a set distance from the weld surface.
3. Gas Flow Rate and Type/Mixture
For those of you who are used to flux-cored welding or are generally new to welding you may be wondering how to set up a MIG welder with gas. MIG welding uses shielding gas to protect the weld from harmful atmospheric particles during the work process. It is important that your gas is pumping out at the right rate and that the gas coming out is the correct kind for the project.
A well-balanced flow rate would be around 20 – 24 ft3/hour. You will know there is too much or too little pressure by the strange sounds coming out of your gun if the problem exists.
As for the gas type/mix, if you need high heat because you are welding thicker metal or simply need greater surface penetration, use 100% carbon dioxide.
If your metal is medium or slightly thin, us a mix of 25% carbon dioxide to 75% argon.
If you intend on welding thin metal, such as aluminium or sheet steel, use 100% argon gas.
MIG Welder Settings Guide for Metals
1. Settings for Aluminium
Aluminium MIG welding settings are in the lighter, cooler side of the settings range. Aluminium is not very dense and is in most cases very thin. You need to keep your voltage on the lower end of the spectrum for this metal. If your arc is too hot you will burn straight through the whole plate instead of joining to it. You also need to make sure you use argon instead of carbon dioxide as your shielding gas. You may be able to get away with the 75/25 ratio mix, but why risk it? Your wire feed speed will also be slightly lower here as you are not burning through as much wire as quickly as you would with thicker metals. Your polarity stays at DCEP as with all welds.
2. Settings for Stainless Steel
Stainless steel can be a tricky metal to weld due to its tendency to disfigure under heat. It also tends to be anti-corrosive which, while helpful as a metal property, can get in the way of welding with it.
The best gas to use is definitely an argon/carbon dioxide mix. There is the option of a three-way mix between helium, argon, and carbon dioxide if you’re feeling adventurous.
Voltage parameters will be set out in the guide on the inside of your machine and are dictated by the thickness of the sheet you are welding. This in-turn will decide your wire feed speed. Keep your polarity at DCEP
These parameters can also be considered the MIG welding settings for mild steel, provided the mild steel is in thinner quantity and you do not require particularly deep penetration. Keep in mind however, the wire you’d use with these settings would be different.
Keep in mind the unique properties of stainless steel when welding. The settings will not affect the weld as much as your technique will if it is not on point.
3. Settings for Common Steel
Common steel is By far the easiest metal to weld as it is the most forgiving. It is denser than metals such as aluminium and requires more heat and a faster wire feed speed. The specific parameters will be decided by the specific thickness of the piece you are welding at the time.
I suggest you first try out carbon dioxide as your shielding gas. If the weld cuts too deep or splatters too much, go for the 25/75 ratio mix.
I suggest a gas flow rate of between 23 and 30 ft3/h Depending on how thick your steel is.
Other Reminders
Keep in mind that the success of your welds are based just as much on the type of wire you are using as it is on the settings you put it. The settings are also determined by the wire type.
I strongly suggest you always test weld your set-up before putting your gun to the project at hand to ensure you have the optimal settings for the task ahead.
Always, always, wear all your safety gear. MIG welding may be fun, but the fun seeps right out of it when you wake up the next morning with arc-eyes.
If you are not sure that your settings are right for what you need done, contact your welding machine manufacturer and describe the project to them. They will be able to provide very specific settings advice.
MIG welding is a worthwhile trade to have, be it for day-to-day fixes or as a profession. With the right machine, right materials, right welding techniques, and the right settings, becoming a respectable MIG welder is quite attainable. Always remember, trial and error are your best teachers, and practice is your best friend. Good luck and happy welding!
