To be a successful welder you just not only need to know the art of welding but also how to undo it. It will save you when you get messed up. Also, it’s very helpful to reuse the welded piece in a new project.
Welding is the process of joining metal pieces in a permanent joint with the help of electricity. You do welding to create or repair something. Welding is used in every industry to make complex structures and frameworks out of metal.
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How to break a Weld?
Now the question is how to break a weld? Some efficient methods will help you in removing welds. Let’s list them down and discuss them one by one.
- Cutting with a plasma torch
- Using gas/oxy-acetylene torch
- Punching the weld using an arc or stick welder
- Physically breaking the weld
- Mechanical methods (hammers, chisels, and other manual metalworking tools)
1. Plasma cutting:
The plasma torch is the latest invention of the welding world. If you want clean and precise cuts in metal that’s what you need a plasma torch. Moreover, it is very famous and comes at a price range that makes them affordable for professional welders.
The plasma cutting process involves cutting through an electrical conductor with the help of an accelerated jet of hot plasma. You press the torch and heat is generated by high-pressure airflow that comes out of the nozzle. Furthermore, the plasma temperature reaches up to 20,000 Celsius hot enough to easily break a weld.
Plasma cutting is very beneficial; it has a high cutting speed which is five times greater than the manual torches. Also, plasma cutting is very efficient using a plasma torch you can cut through a wide range of materials of various thicknesses. They are user-friendly and don’t involve any flammable gases meaning they are safer and economical than water-jet and laser cutting.
What Do You Need to Gouge with a Plasma Cutter?
You need a plasma cutter. The prices of smaller plasma torches have come down in past years but the big ones are still a little out of budget. However, if you can afford one it’s a must-have as in welding you will require all the safety gadgets.
More than anything you require is practice. Learn the speed, power, and angles of attack keys. Just put your maximum time and effort to become an expert with plasma cutting.
Once you learn the art of plasma cutting it will benefit you in numerous ways. It’s the most satisfying method as it’s easier and faster.
2. Gas/oxy-acetylene torch:
Oxy-fuel torches are a very important part of a metal shop. They are not only used for cutting and welding but they also perform several other functions including removing welds.
Most welders who use gas torches use oxy-acetylene gas to break the weld. Other gases are also useful but they may require different settings and equipment. Moreover, oxy-acetylene is easily accessible and best suited for gas torches.
There are many good reasons to use flame gouging one of which is it’s much quieter than a grinder. Also, it’s a faster method to break a weld than cold chipping at welds.
Gouging
Flame gouging heats the steel to 900-degree C or about 1650-degree F. At this temperature metal melts and weld breaks. This method requires time to master. A welder needs to learn the speed of the torch and the angles of the torch.
While using a flame gouging method try breaking the weld carefully otherwise it can cause the metal to buckle and distort.
You are heating the metal at a high temperature. Be careful as it can splatter and become hazardous. Also, you are removing a metal weld from both sides of the workpiece. Now the missing metal piece may affect the piece’s usability after breaking the weld.
Cutting Metal
It’s not a problem for an oxy-acetylene torch to cut the metal as it excels in it. A weld is a metal, and oxy-acetylene easily cuts it like another metal but that is not always the case.
It is important to understand how the oxy-acetylene torch cuts the metal. When using an oxy-acetylene torch to cut metal, the acetylene flame heats the metal to its kindling point. At this temperature, the oxygen valve on the torch opens, sending a stream of oxygen onto the hot metal which oxidizes and blows through the cut as slag.
Welders mostly weld in two ways either they join the two metal pieces along the joint using a gas torch or an electric arc or by using an additional metal piece between the two subject metal pieces. An extra metal provides strength and proves to be a stronger option.
Cutting an existing weld is just like cutting through metal. What’s important is to understand the metal characteristic of the weld. While cutting, always keep in mind that there will always be a place for the molten slag to escape. Be sure you are making an opening on the other side of the metal.
Trying to break a surface weld and keep the bottom piece of metal intact is almost impossible using an oxy-acetylene cutting torch. Moreover, to be successful, the lower piece of metal will have to be perforated or cut to allow the slag a way to escape.
The advantage of using an oxy-acetylene cutting torch includes removing welds efficiently and effectively. More ever it’s very effective for turning metal into bends, twists, and wraps. Lastly, it’s easily accessible and with practice, your query of how to break a weld will be solved easily.
3. Arc or stick welding to break a weld:
Arc welding or stick welding serves both purposes; it breaks the weld as well as joins the metal pieces together. This process is called carbon arc welding intense arc heat is created at the tip of the electrode which melts the metal. Once the metal is melted air steam blows the melted metal.
It requires special equipment with a nozzle attached to the jaw holding the electrode. Moreover, it has an operator which handles the air which breaks the weld. This air connection doesn’t require any compressor for the necessary flow rate.
Welding Rod
The rods are very important for the air arc to weld and join the two pieces of metal so select them carefully. There are different types of rods for arc welding such as:
- DC coated rods and DC plain rods
- AC coated rods
As the name indicates AC rods are for AC power source welders and DC rods are for DC welders. DC rods are a good choice for gouging. Their benefits include long life, low electrical resistance, and versatility (comes in several sizes and shapes).
The Torch for welding
Torches play an important role in a welder’s life; they make welding easy and less hazardous. They have one or two nozzles as an opening from where gas or plasma jets come out. While buying a torch for welding, always check its cables, that they are properly protected and connected.
Arc-gouging is an expense as it requires a large shop air compressor. Moreover, air-arc gouging is very loud when you are doing arc welding with it and the air compressor is also on the sound itself is deafening.
Air-arc welding process
Now you have the right equipment according to your need and pocket size. Let’s remove the weld.
- On the arc-welding torch and strike an arc on the weld. Keep rotating the metal piece according to the need and continue to add some side-to-side motion depending on the size of the gouge.
- Once the arc is out don’t be hesitant and keep moving the electrode forward and more close to the weld.
- When the direct air jet passes from the electrode, you will observe that the molten metal is blown away from the arc as you proceed.
- Maintain the arc temperature at 35-45 degree as you move forward it along the gouge line.
Air-arc gouging vs Gas torch:
Air-arc gouging requires skill as it’s challenging to maintain its position and combination. But once you master the skill of air-arc gouging it provides good results.
Gouging or welding with a gas torch is much easier than air-arc gouging. It’s easy to maintain and position. It also provides a good result and is user-friendly.
Both the air-arc gouging and gas torch are destructive processes in nature. And almost requires the same temperature while gouging. These processes require a lot of stress and if not taken care high chances exist that they are capable of making metal pieces useless.
4. Physically removing the welds:
If you are not using any electrical equipment you can also remove the break the weld physically. Physical distortion is possible. Many laboratories opt for this method to remove the weld on a routine basis.
What’s important in physical distortion is checking the quality of welds so that we know how much pressure is necessary. Normally for measuring the force laboratories use different machines. Moreover, these machines also check how well the two metal pieces are fused to gather in other words, the strength of the weld.
In this process fabricators in desperation always use the largest hammers they can find to break a weld. Mostly while trying to remove a weld physically many deformities occur and metal bend and become useless. It happens because often the weld is more strong than the two metal pieces it’s present between.
So it’s not preferable to use this method as the success rate is very less.
5. Mechanical Method:
If you are wondering how to break a weld manually you have come to the right place. Yes, in the mechanical method it is possible you just have to perform a few actions depending upon the weld you are dealing with.
For example, spot-welded sheets are difficult to handle when you perform the separating process by using a drill. It’s also possible that during separation you might damage the base metal. In the mechanical process, we mostly use drills, grinders, and cutters.
Removing welds without grinders
If you want to break the weld without a grinder your options are mentioned above you can use drills, plasma, and oxyacetylene torches to break the weld.
Steps to take
- Mark the area of the weld where you want to cut. The marking doesn’t require any special tool to mark use any pen or pencil.
- Then by using clamp or vices hold the metal pieces so that it doesn’t move while cutting.
- Now choose your equipment to make a cut and set it accordingly. If you are using a plasma torch connect it with the power cord and turn on the torch. However, if you are using a gas torch don’t forget to own the gas cylinder. Furthermore, in both cases don’t forget to adjust the flame according to the need and nature of the weld
- Now move your tool torch or saw anything along the mark you made with pencil or cut. Try doing it with care as it’s dangerous and slowly move along the line but don’t linger too long on the same point. Do this on repeat till you are successfully cut the weld.
- As the cut is made on the weld turn off your tool and let it cool. Don’t handle them instantly as they will be too hot and might burn you badly.
Removing welds with grinders and circular saw
Grinders are used to create beveled edges, prepare the metal surface, and cut the weld. The cuts made with grinders are that precise as the cuts made with plasma cutting yet many small-scale welders use this approach. Moreover, it’s a cheaper method and less heat is produced in this approach making it less hazardous.
Steps to take
- Mark the place on the weld where the cutting is required with the help of a pen.
- Hold the metal pieces with clamps and vice so that they don’t move.
- For protection put your protective gear.
- Connect the grinder with the electricity.
- Now slowly place the grinder on the marked area and slow start the cutting. Don’t put pressure otherwise, the base metal will ruin. If you put too much pressure the cutting disc will break and it will be dangerous.
- Once you are successful in cutting let the metal cool down. The heat you are feeling is due to the friction and not because of the grinder, unlike other equipment.
Which Method is better for you?
Often welders at the beginning stage who are wondering how to break a weld inquire what is the best method of undoing a weld.
Well, it depends upon the base of the metal. If the weld sheet is strong it will require much stronger equipment for removing a weld.
Also, it depends on the welder how much they can afford and what’s their goal. If you can purchase good equipment Plasma cutting is the latest and best method as it is safe and provides precision.
People also read about: Brass to Brass welding
Conclusion:
No task is impossible, some tasks are just more costly and time-consuming than the others. It’s the same for the removal of welds and with the latest technology, the query of how to break weld is solved.
All the methods mentioned above are genuine and they will help you break the weld but which method is perfect for you depends on several factors such, affordability, nature of metal, and skills required to handle particular equipment.
So you can use an oxy-acetylene torch, plasma torch, arc or stick cutting, or grinders to break the weld. All the options are available to choose the best suited for the job and you will be successful in removing the weld.
Source:
https://aip.scitation.org/doi/full/10.1063/1.5132776
What are the causes of bad welding?
Bad welding can be a result of many things. Either air may have crept into the weld to cause porosity, or heat can cause cracking. Sometimes bad welding techniques can contribute to the problem.
Is it possible to weld over a weld?
Yes, it is possible. Welding over welds is very common, though there are some concerns.
Differences in welding procedures of overlapping welds – such as heat inputs or cooling rates of the two metals can cause problems. Compositional variation can also lead to issues.
How do you know a weld is bad?
There are some signs of a bad weld. Though different types of welding have different signs, these could have some overlap, such as undercutting, thin welding lines, porosity, lack of uniformity, cracking, spatter, etc.
How to break down old welds?
In the welding and fabricating industry, methods of breaking welds without a grinder include:
- Try to use an oxy-acetylene torch also known as a gas torch.
- Punching the weld using an arc or stick welder.
- Gouging with a Plasma Torch.
- Mechanical methods include hammers, chisels, and other manual metalworking tools.
- Physically breaking the weld.
What is the best way to cut welds?
It depends on the need and nature of the metal but mostly you can remove welding through plasma cutting, torch cutting, arc or stick welding, grinding or circular saws, drills, or oxy-acetylene torches.
How do we differentiate between a good weld and the bad one?
A bad weld includes a Lack of uniformity, cracks down the middle of the bead, too thin, and/or a lack of discoloration of the parent metal (which should be about 1/8 of an inch).
What are the 4 types of welding?
Mainly there are four types of welding.
- MIG – Gas Metal Arc Welding (GMAW)
- Flux-cored – Flux-cored Arc Welding (FCAW)
- Stick – Shielded Metal Arc Welding (SMAW)
- TIG – Gas Tungsten Arc Welding (GTAW)
Among minor other mechanical methods include hammer saw and grinders.
Also read our article: 11 best welding schools in the USA
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