If you have ever tried to weld, you know there’s no shortage of things that can go wrong. One of the most common welding defects you might be facing is overlapping. But not anymore. Because in this article, I am going to provide you with 9 great tips to prevent overlap in welding.
To avoid overlapping you must be making sure you’re not using too much current and your travel speed isn’t too slow. Cleaning the base metal properly and welding at the right angle are necessary prevention methods. Choosing the right electrode size, making sure your arc length isn’t too short, and so on are some other tips to prevent overlap.
However, simply knowing this may not be enough. That is why in this article, I will go into detail about what causes overlap in welding. Then, I’ll go over some comprehensive preventive measures to ensure you understand exactly how to weld to avoid overlapping. With the help of all of this information, you will undoubtedly be able to say goodbye to welding overlap for good.
What Causes Welding Overlap?
Weld metal flowing out of the joint without melting the base metal causes overlap. Thus if the molten metal does not fuse with the metal base, it will overlap. So it is caused by the overflow of the weld pool.
This overflow is caused for various different reasons. Excess current, wrong weld angle, slow speed of travel of welding, slow electric manipulations, inexperience are some of the reasons for welding overlap.
- Use of Excess Current
If you use too much current, it will cause the weld material to over-melt, which will cause an overflow above the metal and cause overlap.
If you use excess current, it will increase the temperature. The temperature rises differently for different types of welding, but it does increase. This increase in temperature is what causes the over-melting of the weld material.
| Type of Welding | Type of Joint | Temperature (°C) 70A | Temperature (°C) 90A | Temperature (°C) 110A | Temperature (°C) 140A |
| MIG | Butt | 950 | 983 | 991 | 1027 |
| MIG | Lap | 1115 | 1117 | 1137 | 1155 |
| TIG | Butt | 1000 | 1143 | 1343 | 1410 |
| TIG | Lap | 1172 | 1265 | 1311 | 1378 |
The increase in temperature impacts the temperature a lot more in TIG welding. But the rise in temperature with current is not at all negligible for MIG welding either. So in any type of welding, the temperature will significantly rise if you use excess current.
So, if you use excess current, you will have to face instances of overlap throughout your welding.
- Use of Low Travel Speed
If your weld travel speed is too slow, it will cause a lot of weld metal to be lumped up in the base material. It is pretty wasteful because it doesn’t contribute to any strength to the weld. The extra weld will just sit on the material’s surface without fusing, which will lead to overlap.
Depending on the material’s thickness, you might get too much heat in the material if you go slowly. The excess heat can over-melt the base metal and cause overlap in your welding.
| Travel Speed(IPM) | Heat Input(kJ/in) |
| 7 | 22.66 |
| 11 | 19.26 |
| 19 | 17.01 |
- Use of Wrong Travel and Work Angle
The bead profile can also be influenced by welding technique and torch travel angle. A wide travel angle can result in a convex, poorly formed bead with low penetration, leading to overlapping in your welding.
It is the opposite of work angle. If you use a small work angle, a lack of fusion will occur. If the weld metal is not fused correctly with the base metal, it will cause overlap in your welding.
Depending on the type of welding you are doing, you need to choose either the forehand or backhand technique. The backhand technique produces deeper penetration and a narrower weld profile with greater convexity than the forehand technique. So if you don’t choose the correct procedure according to the type of weld, you might face overlap.
- Use of Large Electrode Size
The electrode size affects the configuration of the weld bead. For the same metal transfer properties, a bigger electrode demands more current than a smaller one. Increased currents result in melting of the electrode and increased fluid weld deposition. Deposition concentrations are also higher when currents are higher.
That’s why if you use a large electrode, more weld material is going to be on top of the base material. This will cause overlap.
- Taking Short-Arc Length and Electrode Extension
You could find a nozzle full of spatter or even a melted tip if your arc length is short and you get too close to the melted metal of your weld. This spatter will cause overlap in your welding. Again if you take the arc length too short, it will give higher heat input to the base metal. This can lead to overlap.
Electron extension creates distance from the base material. In doing so, it gives less heat input to the base material. But if the electrode extension is too short, then it might generate more heat and cause overlap.
Arc length and electrode extension combined make contact to work distance. If the contact to work distance is short, it will give higher heat input and cause overlap. If you use short contact to work, it will need more current, and excess current can also cause overlap.
| Contact to Work Distance(inch) | Current(A) | Heat Input(kJ/in) |
| 3/8 | 198 | 19.64 |
| 1/2 | 174 | 16.91 |
| 5/8 | 164 | 16.27 |
| 3/4 | 151 | 14.92 |
| 7/8 | 143 | 14.13 |
| 1 | 136 | 13.38 |
- Taking Large Bevel Angle
If you take your bevel angle too large in your welding process, then there is a chance that you will face overlap. It generally causes overlap in the front face. Bevel angle comes to play when you are doing joint designs in welding.
- Use of the Wrong Manipulation of Electrode
If you choose the wrong electrode manipulation technique, you might face a range of defects in your welding, including overlap. You need to select your electrode manipulation technique based on your skill and experience.
Electrode manipulation may take the form of a weave, whip, pull, or push motion. Depending on the thickness of the material, you need to use different electron manipulation techniques. For material 1/4 inches or thinner, a simple straight bead. For thicker materials than 1/4, weaving, etc. If you don’t correctly choose the manipulation techniques based on thickness, you will have overlap in your welding.
- Use of Unclean Metal Base
You need to avoid painted metal, dirty metal, rusty metal, and so on at all costs. No matter how good your skill is, your welding will be terrible if the metal base is contaminated. These contaminations in your metal base will create an overlap in your welding.
The metal base needs to be smooth as well. If you try to weld in a metal base that doesn’t have a smooth surface, you will end up with a sloppy weld and overlap in your welding.
Check our article about MIG Welder Keeps Jamming? Here’s What to Do
How to Prevent Overlapping in Welding?
To avoid welding overlap, make sure you’re not using too much current and that your travel speed isn’t too slow. Cleaning the base metal properly, welding at the proper angle, selecting the appropriate electrode size, and so on are some other preventive methods to avoid overlap.
Don’t worry if that was too much to process all at once. I am going to break down each and every one of the prevention methods listed up there and more. I will mention 9 tips that will change your whole welding experience. If you follow all of these tips, you will never face overlap in welding ever again.
With all that said, here are the 9 great tips to prevent overlap in welding.
Tip 1: Use the Appropriate Amount of Current
You should adjust your current depending on what you’re welding. The alternating or direct current levels should be appropriate for the job at hand. Glowing or over-brightening of an electrode indicates that you are using too much current or that too much current will enter the welding point.
The amperage-to-electrode-diameter ratio should be 1:1000. This means that for a quarter-inch diameter, your welding procedure would require approximately 250 amps. Remember that if you use too much current, then the weld material will over-melt. That’s why make sure the current you’re using does not exceed the suggested limit.
Tip 2: Maintain Moderate Travel Speed
Make sure your travel speed is not too slow. Slow travel speed is one of the main reasons behind welding overlap.
But that doesn’t mean your travel speed should be too fast. If you use too fast travel speed, it can reduce penetration, deteriorate the bead’s surface. It can also cause undercutting at the weld’s edges, make slag removal difficult, and entrap gas (porosity) in the weld metal.
You will face a problem if you keep your travel speed either too slow or too fast. That’s why you must maintain a moderate travel speed. Keep in mind that low travel speed is much more likely to cause overlap. So you must not weld with low travel speed.
Tip 3: Use Small Electrodes
With large electrodes, there’s a good chance you’ll apply too much weld material to the surface. It’s best to use small electrodes to prevent overlapping. Small electrodes reduce the distance by using less weld at each point. So if you use small electrodes, excess materials and overlaps are less likely to occur.
Our recommended electrodes Hobart 770473 6013 Stick.
They burn clean and great for beginners.
Tip 4: Improve Your Technique
Overlap is caused by inexperience or a procedure that does not correctly correspond to the task at hand. Keep in mind that welding methods differ significantly depending on the type of metal used and whether the welder is using MIG, TIG, or Stick welding.
To get a good quality weld without any overlap, you need to have various types of preparation. You will also need techniques and special materials such as shielding gas, which you must use properly.
Welding is a skill that everyone has to master with practice. Slow welding, for example, causes the weld material to overlap. You just need to think about the welding speed to fix this. This comes with practice. Also, the way you match your materials is crucial. You’ll need adequate planning and a good selection of materials depending on the welding technique.
Tip 5: Properly Clean the Base Metal
To ensure a strong weld, clean the metal beforehand to remove any pollutants. This is because it can obstruct welding, cause resistance, overlap, and even cause a weld spill. If the metal to be welded has rust, paint, dirt, or mill scale, you must clean it first.
There are various methods to clean your base metal. Let’s go through them
Angle grinder
Angle grinders are fast and effective at removing large contaminants. If you’re working with tough materials, you’re better off using an angle grinder. You can ruin the metal you want to weld by misgauging it if you’re not careful.
Sandpaper
Rust and paint can be removed with sandpaper. While a coarser grit will speed up the process, it will also scratch the metal. On metal, aluminum oxide paper can last longer. If you’re washing rust off of equipment, you’ll need 80–100 grit. Don’t go coarser than 150 grit if you want a good finish on something like furniture.
Abrasive blasting
Abrasive blasting, also known as sandblasting, is mainly used for more complex cleaning. Sandpapering a metal that has a coating or is extremely rusted is possibly a waste of time. If the paint is fused to the metal, you’ll also need to blast it.
Wire Brush
When it comes to getting into odd angles and grooves, nothing beats a wire brush. They’re ideal for removing light pollutants such as flaky paint, rust, and splattered welds. You can clean quickly and lightly with a crimped wire brush or more thoroughly with a knotted brush.
Before you start your welding, you need to make sure of a couple of things to ensure that the metal is cleaned correctly.
- Make sure there aren’t any deep grooves or markings on the surface.
- Make sure the metal is completely dry.
- Don’t cut too much of the surface, especially if the metal is thin.
Tip 6: Use Proper Work and Travel Angle
Depending on the kind of weld you are trying to do, you must choose your work and travel angle. If you are not careful choosing, you are going to end up with overlap in your welding. You must decide whether to use a backhand or forehand, depending on your weld.
| Type of Joint | Position of Welding | Work Angle(Deg) | Travel Angle(Deg) | Technique of Welding |
| Groove | Flat | 90 | 5-10 | Backhand |
| Groove | Horizontal | 80-100 | 5-10 | Backhand |
| Groove | Vertical-Up | 90 | 5-10 | Forehand |
| Groove | Overhead | 90 | 5-10 | Backhand |
| Fillet | Horizontal | 45 | 5-10 | Backhand |
| Fillet | Vertical-Up | 35-55 | 5-10 | Forehand |
| Fillet | Overhead | 30-45 | 5-10 | Backhand |
Tip 7: Use Appropriate Arc Length and Electrode Extension
The arc length is determined by the arc stability, weld current, and part concentricity. In general, the arc length is 0.10 inches.
If you take your arc length too short, there will be higher metal deposition with a narrow width bead which will cause overlap. So if you want to avoid overlap in your welding, taking short arc length is not an option.
However, you can’t take too long arc length as well. Your arc will become unstable, and the penetration and fusion will be too poor.
That’s why to get appropriate spatter and great fusion and penetration, and most importantly, to avoid overlap, you must take the proper arc length.
Tip 8: Learn to Properly Manipulate Electrode
This is one of the things you must master on your own. Each welder manipulates in his or her own unique way. As a result, manipulation techniques differ from person to person. You must practice finding the method that is most comfortable for you. You should observe how experts do it and use it to develop your own style.
You also need to make sure you choose the proper electrode manipulation techniques based on the material’s thickness.
Tip 9: Use Moderate Bevel Angle
Different angles are appropriate for various applications. The critical thing to remember is that you must keep the angle within the tolerance level regardless of the degree.
The standard bevel in most cases of beveling pipe is a 37.5 degrees angle. But this is not the case for the metal application. So check what bevel angle you have to keep for your application and maintain that.
If you still have some overlap in your welding, you can remove it by grinding the weld bead smoothly to the base metal. The offensive notch will be removed as a result of this.
Conclusion
These are the 9 great tips to prevent overlap in welding. If you follow all of the tips correctly, you will not have any welding overlap. That’s one less defect in your welding to be concerned about. I wish you all the best in your future welding endeavors. Thank you for taking the time to read the article.
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