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The growing DIY movement means many more people are now welding.
I think that's great, but there's a downside...
There are many people out there with welding machines who have no formal training.
This means some people don't understand some of the fine details that welders learn in school.
One of those details is setting the right parameters on your new MIG welder for the job at hand.
You're probably here for that reason, so I'll explain the main MIG settings and how they should be adjusted.
Now let's set up the machine properly...
Before setting up your MIG controls
There's more to it than grabbing your MIG machine and turning the dials.
As with any welding process, your MIG settings are highly dependent on the task you are tackling.
There is no generic selection of settings that always apply. Welding is an individual craft and depends on many variables.
What's your material?
Different materials have different properties in terms of heat and electricity. It matters a lot what material you are welding. The properties of mild steel are very different from those of aluminium.
Aluminum does not melt at the same temperature as mild steel and does not conduct electricity or retain heat to the same extent as stainless steel or titanium.
Before you can even get started, you have to choose the right process and take care of the mechanical and technical structure. The selected wire, shielding gas and machine settings depend on the material.
Mild steel, aluminum and stainless steel or nickel alloys are the most commonly used metals in the MIG process. They are the main metal found in homes and cars.
How thick is the metal?
Know the thickness of the metal so you know if your welder has the power to get the job done and you can choose the right electrode wire and shielding gas.
You can plan how to approach your project in terms of setup, angle of attack, cooling and handling of your projectWelder duty cycle, and other practical solutions.
You adjust the amperage according to the thickness of the metal. Therefore, you need to know how thick your metal is.
As a general rule of thumb, you need 1 amp of current for every .001 inch of steel.
Stainless steel requires 10-15 percent less electricity and aluminum about 25 percent more.
So how many amps does it take to weld 3/8 steel?
For 1/8" mild steel that is .125" thick, 125 amps would be a good starting point.
3/8 inch thickness is .375 (3 x .125) so do you really need 375 amps for that? Some welders claim to weld 3/8 inch steel at only 170-200 amps. How is that possible?
First, these numbers are estimates. They only take you to the stadium.
Second, manufacturers do a little magic to advertise performance with these numbers. You'll bevel the edges of the joint to reduce the thickness. In this way, the same weld can be made in one pass with less current.
shielding gas and electrode wire
For good results it is necessary to use the right shielding gas and the right electrode. These decisions are heavily influenced by material composition and thickness.
Some wire and gas combinations that are common in MIG welding are:
- mild/carbon steel– ER70s wire and 75/25 percent Argon to CO2 ratio
- stainless– ER308L wire and 98% Argon with 2% CO2
- Aluminium- ER4043 wire and 100% Argon shield
FromChoose your wire sizeby the set current, which in turn depends on the material thickness. Here are the most commonly used wire sizes in MIG welding.
Note that these sizes overlap in each current range. This gives you the choice of what works best for your welder and your technique.
- 0,023 – 30-130 Ampere
- 0,030 – 40-145 Ampere
- 0,035 – 50-180 Ampere
- 0,045 – 75-250 Ampere
High-quality welding equipment makes work easier. For example toWelding aluminum with a MIG welder, it is better to install a spool gun for trouble-free wire feeding. Make sure your shielding gas cylinder is full and the connections are clean and tight.
Some MIG welders automate most of the setup process, making setup easy.
Built-in digital menus and input variables such as material type and thickness automatically set up the MIG welder.
You still need to load the right wire and gas, but some of the tricky setup is done for you.
Check out oursGuide for MIG weldersfor information on some of these machines.
Prepare your workpiece
In order to achieve excellent welding results that are repeatable, your metal must be willing to work on it.
Preparatory metalwork includes:
- The fat
Settings do not produce good welds; They only make good welds possible. But only if you do the rest.
Three things to keep in mind when preparing together:
- Clean joint, clean bead
- Dirty metal settings do not apply to clean metal
- Less oil or paint to catch fire means less to think about
MIG welding settings for mild steel
Now... let's make some adjustments...
For the sake of simplicity, I'll stick with the mild steel settings for the most part, since it's by far the most commonly welded metal in the world.
I will mention aluminum or other materials whenever relevant.
Which MIG settings are most important?
While your welder may have a nice range of settings, it's important to understand that most of them are for fine-tuning.
Three basic settings determine the rest. These basic settings are:
- tension level
- Wire Feed Speed (WFS)
- Type and rate of shielding gas
You want to create the right heat conditions at the weld to create a smooth arc, avoid spatter, and maximize penetration.
These settings also determine the type of transfer for metal deposition. Read more aboutMIG transmission types here.
1. Voltage level
The MIG power source is a constant voltage system. Once it's set to a certain level, the voltage won't vary much. The voltage determines the arc length and the height and width of the bead.
Fine tuning the voltage is a trial and error process. This is checked by examining the pearl for imperfections. I've included a chart below to help you choose your tension by examining the bead.
2. Wire feed speed
Wire Feed Speed (WFS) affects your heat level. It is measured in inches per minute (IPM). If the feed rate is low, the weld area may become too cool for good penetration.
Higher feed speeds allow better contact between the wire and the weld pool. Increase the current level and generate too much heatleads to spatter.
Voltage level and feed rate must be coordinated.
If sparks are flying everywhere and you have spatter the size of the filler wire or larger, you have one of two situations:
- Too much WFS for voltage setting
- Insufficient voltage for the WFS setting.
If the arc flares back up in the tip, you have one of two situations:
- Too much voltage for the WFS setting
- Foo little WFS for voltage adjustment.”
There is another critical factor in your wire feed speed: the distance the electrode wire protrudes from the contact tip of the MIG gun.
This distance is called Electrode Stickout (ESO) and is a limiting factor. You must maintain a constant distance over the workpiece when welding, or you may not be able to get consistent results with your settings. Make it a habit to check your ESO Distance regularly.
3. Gas type and quantity
The flow rate, volume and type of shielding gas determine the type of transmission in combination with voltage and wire speed.
Higher concentrations of helium or argon result in a hotter arc. The whole purpose of shielding gas is to protect the arc and weld puddle from oxygen. The nature of pressurized gas flow requires experimentation and analysis. In other words, trial and error.
related reading:MIG welding gas pressure adjustment
Gas is measured in cubic feet per minute (CFM) and drafts, wind or cylinder temperatures will affect the results.
Perhaps when things stand still, 5 CFM will be enough to properly shield the weld. But leave a door open, and a draft can blow the gas away at that rate, so you need to go to 35 CFM, for example.
However, if there is too much gas pressure at the weld, you can draw oxygen into the arc plasma and contaminate the bead.cause porosity.
MIG Weld Settings Chart - Wire Speed and Voltage
There are many MIG setting charts from manufacturers, all of which are different.
Here's a settings chart I've put together to serve as a general guide to get you started - remember this is a guide only.
Always test your settings on a piece of metal. Depending on your setup, you may need to dial them in.
What the weld tells you about your MIG settings
Another way to check your MIG settings is to inspect the weld bead. It will tell you what it needs. You just have to be careful...
- Normal Pearls: Good base penetration, low profile, reasonable width and good binding at the ends.
- Amps set too low: Narrow, possibly convex, ridge with poor integration at the ends.
- amps too high: Poor arc start, bead too wide, burn through, lots of spatter and poor penetration.
- Traveling too fast: Moving your bowing hand too quickly will result in a narrow, convex bead, poor engagement at the ends, poor penetration, and an uneven bead.
- travel too slow: Running too slowly adds too much heat, resulting in too wide a bead and poor penetration.
- arc too long: Caused by excessive voltage. Long, thin arc, poor penetration and turbulence in the weld puddle.
- No shielding gas: A lack of shielding gas causes porosity and pinholes in the bead.
Now you know
It may be disappointing for some to find that there is no quick, easy answer to the questions you are grappling with. With welding, that's the nature of the game, I'm afraid.
Do not take this information and these charts as gospel or science. This is just a start. The rest of your craft is up to you. These are guidelines only. Watch your weld puddle and inspect your welds.
They have engaged in a craft. Manual labor is inherently non-scientific. It's a challenge, and most of the time the only reward is quiet victory over your last bad habit.