What Is Burnback On A MIG Welder?

Metal Inert Gas (MIG) or Gas Metal Arc Welding (GMAW) is one of the most commonly used welding techniques that has tons of applications in every industry. 

Despite the numerous advantages of this welding method, it can run into some issues from time to time. One of those issues is known as burnback. 

The issue is pretty common for beginners and can occur because of a number of reasons. So, if you are new to the world of MIG welding, then it is possible you are not familiar with this issue. 

So, if you are also wondering “What is burnback on a MIG welder?”, then you have come to just the right place. 

In this article, I will be discussing what causes burnback during MIG welding and what you can do to deal with this issue. 

Without any further ado, let’s get right to it. 

Understanding What Burnback Is

It is imperative to understand the issue first and its causes to be able to deal with it. In simple words:

Burnback takes place when the electric arc that is responsible for generating heat inadvertently travels up the filler wire and fuses the wire with the contact tip of the welding gun. 

This unintended fusion not only disrupts the welding process but can also damage the welding gun itself.

There can be a lot of reasons for this issue. Identifying the cause is crucial in dealing with the burnback and preventing it from happening again. 

Causes of Burnback in MIG Welding

Here are some of the most common problems that potentially cause burnback:

Improper Grounding

If you haven’t grounded your workpiece properly, it can lead to a potential voltage drop in the middle of the welding process. The poor contact with the ground clamp and voltage drop will lead to continuous wire feeding which can ultimately result in a burnback. 

Improper Workpiece Spacing

Another reason for burnback is crowding your workpiece by not maintaining proper space between the welding gun and the workpiece. This can cause burnback due to excessive electrode protrusion. 

Using Wrong Contact Tip 

You have to ensure that the contact tip you are utilizing is compatible with the wire size. If you are using an incompatible or wrong contact tip, it can lead to poor conductivity, wire dragging and eventually burnback. 

Slow Wire Feed Speed

For MIG welding, you need to maintain an appropriate wire feed speed to achieve a smooth finish. If your wire feed speed is too slow, it can also lead to welding issues including burnback. 

Wrongly Adjusted Tension 

If you have not tensioned the filler wire correctly in a MIG welder, it can lead to erratic wire feeding. Adding too much tension can lead to struggle in wire feeding which can cause the wire to get stuck. So, a stuck wire can lead to burnback. 

Poor Quality Filler Wire

The quality of filler wire and contact tip can significantly impact the weld quality. So, you must use higher-quality materials to reduce the risk of burnback in MIG welding and promote a cleaner arc initiation. 

Using the Wrong or Damaged Liner

If you are using an incompatible liner that is not compatible with the filler wire’s diameter or you are using a damaged liner that is kinked, it can lead to wire feeding issues which will cause burnback. 

Fixing Burnback 

No one is an expert right from the beginning. So, you can face burnback issues in the learning process and must know how to deal with them. 

The very first thing you must understand is that you are going to lose the contact tip. There is no saving it. Hence, you must remove all thoughts of salvaging it by scraping off the burned filler material on it. You will only waste your time on that. 

So, simply take the tip and nozzle off the welding gun, cut the filler wire, install a new contact tip and replace the nozzle. Your welding gun and wire will be as good as new. 

Remember, it doesn’t matter whether the burnback was a bit or too much. If the filler wire has burned back to the contact tip, you will have to replace it completely. 

Yes, technically you can file it off to get rid of the burned material but using it again will increase the likelihood of the issue occurring again because there will be leftover residue on the contact tip.

Not only this, but the residue can also lead to potential weld contamination and a whole lot of other issues. 

So, you must change the contact tip, regardless of the magnitude of the burnback.

Now that you have resolved this issue, let’s take a look at some of the preventive measures that can help you avoid this problem in future. 

I mean, unless you are going to use this method each time you face a burnback issue, you must follow the preventive measures. 

Related: What Causes a MIG Welder to Sputter? A Guide to Fix this Issues

Preventing Burnback From Happening

We have already discussed the most common causes of burnback, and they should have made it obvious how you can prevent it. 

Although burnback is not a major problem and is pretty easy to fix, changing the contact tip does cost you money and also wastes your time. 

So, it will reduce productivity and increase downtime if you run into this issue again and again. 

Here are some of the important precautionary measures you can take to resolve the issue. 

• Increase the wire feed speed. If the wire feed speed is too low, it can lead to multiple issues. So, increasing it is a good way to prevent burnback. 
• Make sure you are using the correct tip size that is compatible with the filler wire. Also, ensure that the contact tip is not damaged. 
• During the MIG welding process, make sure that the distance between the welding gun and the metal is adequate to avoid the risk of burnback. You have to keep at least a space of half an inch.
• Last but not least, you should also focus on getting high-quality materials and not use cheap consumables as they can lead to several issues including burnback. 
• Adjust your wire tension properly. You can check for wire tension according to the filler wire you are using and then finetune your settings to adjust it properly according to specific welding requirements. 
• Use proper and compatible liner. You must ensure that the liner is not damaged or kinked in any way and doesn’t lead to any wire feeding issues. 

Also Read: How to Use the Lincoln Electric Power MIG 140 MP Welder?

Burnback Control – Not To Be Confused With Burnback

Burnback Control is a specific feature that can be found in certain MIG welders. This setting is not to be confused with the burnback issue and serves a different function. 

Basically, the burnback control feature allows you to adjust a setting that will keep the filler wire energized even after it has stopped feeding it to the weld pool. Hence, it will not stick to the workpiece.

So, this feature of welding machines should not be confused with the burnback issue of MIG welding. 

Related: What is the Difference Between a MIG and a Flux Welder?

Frequently Asked Questions

What is the difference between burnback and burnback control?

Burnback refers to an issue in MIG welding in which the filler wire burns back to the contact tip and melts on it. Burnback control refers to a specific setting in some MIG welders that can control the electricity in the filler wire after it has been turned off. 

Can I reuse the contact tip again after the burnback?

It is advised not to use the contact tip any further once it has been the victim of burnback. Scraping off the filler material and using it again can lead to several issues including potential burnback and weld contamination. 

What is the most common cause of burnback in MIG welding?

Wire feeding issues can lead to burnback, so you must look out for them. Other than that, the most common cause includes improper grounding. If you have not attached the ground clamp properly to the workpiece, it can lead to this issue. 

Wrapping Up!

To sum it all up, burnback is a common issue in MIG welding which every beginner might have to face. It is easy to resolve this issue once you understand the underlying causes. 

This guide not only discusses the underlying causes and solutions of burnback in MIG welding but also provides you with detailed preventive measures that can help you avoid this issue. 

With proper knowledge of burnback, you will be able to prevent it from happening in the future and increase your efficiency as a welder. 

If you still have any questions, you can drop them in the comments section below and I will get back to you as soon as I can. Happy Welding!