How To Prevent Burn Through When Welding?

Are you perplexed why those huge, ugly burn-through holes appear on every metal you try to weld?

Don’t worry. I am here to address the matter. Trying so hard to be good at your job and still somehow screwing it up can be very frustrating. But believe me, it is a problem faced by many, and everybody is looking for some secret ways to prevent a burn-through when welding.

What Is Burn Thorough, and Why Does It Occur?

It’s a welding defect, also known as melt-through, which causes a hole in the metal. It usually occurs when you accidentally overheat the metal resulting in the burn of the entire base metal.

Consequently, a hole is formed on the weld joint. Usually, this hole appears exactly on the weld seam or around it. This is more common on thinner gauge metals and those prone to thermal conductivity.

Before proceeding any further, knowing why preventing burn-through is vital is essential.

What is Necessary to Prevent Burn-Thorough?

Melt-through makes the weld joint weak. Generally, a discontinued welding process results in a weak weld. Hence, holes and gaps in the weld make it prone to cracking and impairs under stress. Besides, it also ruins the weld visual look.

So we suggest you go the extra mile to prevent burn thorough and make yourself proud.

What are the Factors Behind Burn-Through?

Poor machine settings is one of the main factor causing metal burn-through.

According to my experience, I suggest you should not ignore the importance of recommended settings. If you do not follow the recommended settings, you can face a major loss of burning base metal. Similarly, you need extra care while joining a metal. If the space is too large in the root of your join, it can cause a burn.

Some metals are too thin that even professional welders can burn through them. We have noticed that metal thickness of less than ¼ inch is more prone to burn.

One of the factors that cause the burn-through is using excessive heat that allows deeper penetration into the base metal.

Most welders use techniques that aid in increasing penetration. But you know, doing too good sometimes results in bad. More penetration sometimes causes melt thorough instead of yielding better results.

How To Prevent Burn Through When Welding?

Some of the factors that help in preventing burn-through before welding are discussed in detail below:

One of the easier things you could do is apply some clay on the back side of the metals, which pulls off the excess heat from the weld so that you won’t see a hole at the end.

1. Clean The Metal Thoroughly

Before getting started on the welding part, you need to clean the metal surfaces thoroughly. The presence of impurities affects the metals’ melting point and the neatness of the result.

For this purpose, you can use a metal grinder or any other tool to remove all the dirt. These impurities can be in the form of grease, paint, or any other gunk stuck on the surface. Cleaning it up will enable you to gauge better the thickness of the metal and the amperage required to weld it.

cleaning the metal piece with grinder

2. Tidy Up The Workplace Before Getting Started

Welding is a specialized process that creates high-voltage sparks that efficiently combust volatile compounds in the environment. So make sure that you clean up your workplace before you start welding.

There should be no combustible compounds in the surroundings. For example, if you are welding an exhaust pipe of your vehicle, make sure that you take the pipe out and far away from the car because there is a chance that the car’s flammable chemicals, such as petrol, may catch fire.

3. Avoiding Long Arc And Short Arc

Another thing that you need to take care of is the distance between the electrode and the base metal. If you hold the electrode too close to the metal, a long arc will occur, and the heat intensity on the metal will increase.

It will make it very difficult for you to control the weld’s direction and the heat’s intensity. Thus, leading to a large, ugly burn-through in the metal piece.

electrode types and material thickness

However, if you hold the electrode too close to the metal piece, then short arcing occurs. When this happens, you risk the electrode sticking to the base metal.

welder using short arc for welding

Besides, the intense focus of heat on a single spot leads to a gaping hole in the metal. Thus, you must maintain an ideal distance between the electrode and the metal to achieve the desired results.

4. Adjust The Pace With Which You Move

Adjusting the pace is an integral part of welding. You can do everything right and still get a burn-through in the metal piece you are working on. This happens because you have not adjusted to an optimum speed.

The speed adjustments depend upon the thermal conductivity of the metal. The lower the conductivity, the slower you move along the metal surface, whereas the higher the conductivity, the faster you move the electrode.

5. Double Check The Equipment

You need to be extra careful with the welding equipment because it should be clean and ready to go before you start welding. The welding machine creates an intense voltage of electricity, and if the machine malfunctions, you are in big trouble.

Besides, the stick holder and the electrodes must be clean and well-kept when not in use. You can also clean the stick holder with a wired brush.

6. Adjusting The Amperage

One of the biggest reasons a burn-through appears on the metal piece is that you cannot adjust the amperage correctly. As I have already told you, different metals have different thermal conductivity and varying thicknesses.

50 amperage on welding machine

It is just a simple formula; the thinner the metal piece, the lower the amperage, and the thicker the metal piece, the higher the amperage.

Safety Measures

The extremely high amperage heat and sparks created while welding damage the human body. Just imagine what the same heat that causes metals to melt can do to your body. Cringy right? So, you must always follow full precautionary measures before starting the welding process. I have prepared a list of some essential measures everybody must always follow.

  1. Wear a face shield to protect your face’s delicate skin and eyes from burning out.
  2. You must wear eye goggles under the shield to add extra protection to the retina.
  3. Wear thick gloves and overalls.
  4. Better wear earmuffs to prevent sparks from entering your ears.
  5. Flame-resistant boots will go a long way in protecting your feet from getting viciously burned.
  6. Clear away all the combustible materials from the surrounding before you begin welding.
  7. Clean the metal surface thoroughly.
  8. Starch your clothes.

Fixing Burn Through?

We can’t guarantee that you won’t make mistakes even if you are a mature welder. So, the welder community has developed some techniques to overcome them.

Melt-throughs are common in professional welding workshops, and you should be familiar with the techniques that help you fix them.

As you already know, burn-through is a minor hole in the weld joint, and you can fill it up with a small weld on that hole. If clumsy edges are around the spot, we suggest you grind them off before inserting the filler metal.


What happens to metal during welding?

Welding is a phenomenal process through which two separate pieces of metals can be joined together. It functions on the property of the metal as a thermal conductive. In this process, you use high heat to melt the metals, after which it is set to cool down.

As the metal cools down, the melted metals fuse, thus joining both pieces. Although it may sound very easy, high levels of focus and practice are required to prevent mishaps. You should seek professional training before getting things welded on your own.

Why do I keep burning through when welding?

You continuously keep burning through the metal when welding because you haven’t cleaned the metal properly before getting started, or maybe because you are using higher heat on that particular piece of metal than recommended.

Different metals have different conductivity and varying thicknesses. You must be careful with the amperage you use on a specific metal. For example, you must use a lower amperage on a thin piece of metal and a higher amperage on a thick piece.


So by now, you know why a burn-through hole is created in the metal surface while welding and how to prevent it; it is time to start implementing them. Remember, a job doesn’t just need to be done; it needs to be done well.

Hence, you must take all the preventative measures to ensure that you achieve an excellent end result while keeping the risks of possible hazards at bay. Practice is the key to perfection. So the more you practice, the less likely you are to get a burn-through when welding.

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Dave Walker is a skilled welder and passionate blogger. With years of experience in welding, he has honed his craft and developed a deep understanding of the trade. In his blog, he shares his experiences, insights, and tips on welding, offering a valuable resource for fellow welders and those interested in the field. He is dedicated to promoting the importance of welding and its applications in various industries.