Why Is My MIG Welder Sputtering?

The top reasons for MIG welder sputtering are:

  • Dirty welder components
  • Dirty wires
  • Poor conductivity or excessive resistance
  • Worn-out liners and contact tips
  • Low gas flow

However, all MIG welding troubleshooting causes are simple fixes.

Why am I facing excessive MIG welder sputtering?

Welding is an intricate process because it is easy to learn but hard to master. It takes to take command over the skill. You have to learn about the contact tips, the welders, gas pressure, wire resistance, and other MIG welding troubleshooting techniques to keep the weld quality top-notch.

So, if you’re encountering MIG welder popping or sputtering, you’ve landed on the right page.

Hello! My name is Jaxon and I’m a veteran welding expert. Keep following and I will share everything there is to know about MIG welding sputtering and how to troubleshoot this problem.

There are simple fixes and you don’t need to go to the manufacturer for troubleshooting your MIG welder.

Reasons why your MIG welder might be sputtering

Causes of MIG Welder Sputtering

The top causes of excessive MIG welding sputtering fall into four categories:

  • Poorly contaminated materials (contact tips)
  • Welding settings (polarity)
  • Equipment issues
  • Welding techniques (gun angle)

Sputtering issues often occur in gas MIG welders. If you don’t know the difference, we have a detailed guide on Gas Vs Gasless MIG Welders here.

The following reasons are a great place to start when troubleshooting MIG welder:

Poor Conductivity/Resistance Along With The MIG Welder Circuitry (Equipment Issues)

If your MIG welder is producing an erratic arc while sputtering excessively, this might be an issue of restricted current flow. Poor conductivity or excessive resistance along the MIG welder circuitry restricts the current flow.

Now, the poor resistance will definitely affect the welding arc as the current that flows through the gun to the arc becomes restricted.

How Does Reduced Current Flow Starts MIG Welder Sputtering?

Most MIG welders send a voltage surge through the power source to overcome the current flow. The sudden surge in the voltage or the increased voltage to overcome the reduced current flow causes your MIG welder to start sputtering and popping.

Many mechanical factors might be responsible for poor conductivity along the circuit. For instance, worn-out contact tips, damaged copper strands within the cables, and a small-sized diffuser which is not suitable for the application in the MIG welder.

Contaminated Components (Dirty Wires Or Contact Tip)

Contamination-free components such as the contact tip or wires are essential to attain efficient and smooth welding results. Therefore, ensuring the cleanliness of the welder components should be the first thing to troubleshoot before you start welding.

Common contamination substances such as metal, spatter or metal coverings could potentially contaminate your contact tips. Moreover, grease, paint, rust, and grime might also compromise the welding quality of the wires.

If any of the contaminants are present at the time of welding, they would likely outgas, burn or turn into bubbles due to the high melting temperatures of the metals.

Why Are External Contaminants Bad During The Welding Process?

The external contaminants, such as grease, rust, or paint cause excessive MIG welder sputtering. Further, it could also damage the components of the welding gun. Therefore, you’d be spending bucks on contact tip replacement or future maintenance.

One of the major reasons to remove scrape off contaminants before welding is that they will mix with the welding puddle. Alas, producing a feeble joint that will ultimately not last long.

It is essential to keep all of the welder components shiny and clean, at all times, to prevent insufficient/weak joints and costly damages.

Welding Settings (Low Gas Flow, Incorrect Polarity Settings)

Another factor to look for while troubleshooting MIG welder is low gas flow. You can’t hope to achieve quality welds with incorrect welding settings and low gas flow.

Why Does Low Gas Flow Impact the Welds And Produce Excessive Spatter?

MIG welding requires shielding gas to protect the weld puddle from external, atmospheric, and physical contaminants.

You are likely to face porosity or get pinhole imperfections without using the shielding gas as protection. The excessive porosity causes the MIG welder to cause sputtering.

But how would you know that your MIG welder system might be running on low gas flow? Well, a pinhole leak and surface porosity in the gas line indicate that the system might be using low gas flow than required.

Using the wrong type of gas also compromises the weld quality and causes sputtering. If the weld surface is covered with sugar or charred-like substance, it is a sign that you need to change the gas type.

What Happens If You Don’t Set The Right Gas Flow For Your MIG Welder?

Considering the right gas flow can be quite tricky with the MIG welder. Set the gas flow too high and you could experience spattering. Set the gas flow too low and you would get sputter.

One way to avoid sputtering and spattering is to have appropriate gas flow and the right shielding type to prevent one of the common welding issues. You could seek help from the welder’s instruction manual before selecting the type and flow rate of the gas.

Equipment Issues (Worn-Out Liners And Damaged Contact Tips)

As with most components of the MIG welder, contact tips and liners are prone to damage as well. Worn-out liners and contact tips could create sputtering during the welding process.

How Does The Quality Of Contact Tips And Liners Impact The MIG Welder Sputtering?

Liners are essential components of your MIG welder because they guide the welding wire from the gun’s wire feeder all the way to the contact tip.

Damaged or worn-out liners compromise the entire gun’s function. They obstruct the ability of the feeding wire to reach the contact tip. In short, they disturb the entire function while causing the MIG welder to sputter and create poor welding arcs.

Whereas, contact tips are vital components in transferring the current flow to the feeding wire consistently. The contact tips create successfully perfect arcs during the welding process when the wire passes through the bore.

Worn-out contact tips will compromise the quality of welds by producing erratic arcs and sputter.

Tips to reduce MIG welder sputtering? – Common resolutions to top sputtering reasons

Tips To Reduce MIG Welder Sputtering

The best way to end sputtering is to troubleshoot the MIG welder for the above problems. While prevention is key to ensure quality welds, you can consider the following resolutions for simple fixes:

Worn-Out Liners or Contact Tips

Liners and contact tips seem to be two of the inexpensive components of the MIG welder. Therefore, you can replace them after several uses.

The best time to replace contact tips is when you notice evident erosion on the bore, missing welds, irregular welds, erratic arcs, and wire replacement offset.

Low Gas Pressure (Flow)

Firstly, determine if there are potential leaks in the welder gas connection, diaphragm vents, or pipe joints. If there are no leaks, cross-check the gas flow on the gauge regulator. Make sure that there is no connection with the orifice in the welder’s outlet fitting.

Contaminated Equipment and Dirty Wires

Clean and scrape off rust, paint, grease, and grime to remove all the risks of contamination. If you are welding on metal, make sure that it is free of rust. Moreover, dispose of the compromised feeding wire.

You could also use a chemical cleaner to remove oxidation from the welding metal. Oxidation is one of the main reasons why most welds fail.

Poor Conductivity/Resistance Along With The Circuitry

Check the following connections to ensure good resistance and current flow along the circuit:

  • Power cable plug of the gun where diffuser, neck, and contact tips reside
  • Power source
  • Work-lead cable where welding wire is present

Make sure that you replace and dispose of damaged wiring and materials of the welder. Another solution is to use compression fittings to reduce the conductivity.


It is quite intricate to pinpoint the MIG welder sputtering cause, especially if you are a novice welder. If you have the right welding equipment, half the problems go away automatically.

The other half of the problems require simple fixes to get you back to an efficient and smooth welding process.

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