Both arc welding and gas welding are well-known terms in the sector of welding. If you are a hobbyist or want to learn about welding, it is a must that you learn about these types of welding.
Gas welding is a welding method which was invented in the 19s. On the other hand, Arc welding is a developed modern method of welding which has brought the solution to many problems in welding.
This writing discusses and compares these two types of welding methods and which suits for which application. To know about this you have to read till the end.
Gas Welding:
If explained in a sentence, gas welding is all about heating the end of the metals to an extent where they melt easily.
It requires the proper equipment so that the accurate melting temperature can be created.
In gas welding, the combination of oxygen along with other gas is used to weld.
Other gases such as acetylene, hydrogen, methane, propane, and butane are used for the purpose. The characteristic of each gas differs upon combustion.
Once the flame is put on, the metal starts to melt, and thus a welding pool is formed.
Then the filler metals are used to fill up the pool.
It also requires some time to harden.
The common application of gas welding is repairing works.
Gas welding is used to weld aircraft parts.
It is also used to build the frames and chassis of the automotive industry.
Gas welding is so effective that it can melt carbon steel as well.
The other applications include brazing, bronze welding, molding metals, and cutting.
How does it work?
In the gas welding process, the metal is melted and joined by heating the metals with a flame that is caused by a reaction of fuel gas and oxygen.
The fusion of metal is achieved by passing the inner cone of the flame over the metal.
You can use this technique to cut thin metals as well.
A sound welding can be obtained by selecting the accurate size of the flame, filler material and the accurate moving of the torch.
Sometimes fluxes are used to remove the oxides from the metals.
It can be applied as paste, powder, liquid or coating.
In case of gas welding, the flames can be divided into 3 types:
1. Neutral flame:
This type of flame can be generated by the equal mixing of the acetylene and oxygen gas.
They burn at the tip of the welding torch.
The inner cone of the flame provides ⅔ heat of the flame and the rest ⅓ is provided by the outer cone.
2. Reducing Flame:
In this flame type an excess amount of gas fuel is used.
The combustion of the gas fuel is found greenish in between the outer and inner cone.
This type of flame is good for welding aluminum, high carbon steels etc.
3. Oxidizing flame:
In this flame type access oxygen is burnt which gives an oxidizing flame. This flame is used to weld brass.
Apart from that there are regulators which are used to control the flow of the gases.
There is also a non-return valve which ensures that the gas does not return to the cylinders.
These are the must have valves that are needed to be checked for proper and safe use of gas welding.
This not it, there are also other equipment that are required to do gas welding.
There is a need for check valves, welding and cutting torch, rose-but torch, and an injector torch.
These are the things which are required to do a perfect gas welding differing to the cuts and joints.
Arc Welding:
Arc welding is the modern welding technique where welding is done using an electric arc. It heats and melts the metals.
The fusion welding process generates a heat up to 6500 F. You can create this temperature both mechanically or manually.
The arc welding technique is divided into two types. It is either consumable or non-consumable.
Electricity works as the source of power in both types. AC and DC both types of electricity are compatible with the process.
To protect the welding from atmospheric contamination the welding region is protected by some shielding, vapor, or slag.
The Arc welding process is widely used in the fabrication of steel and other vehicles.
The process is capable of creating strong joints in almost every manufacturing industry.
It is used to repair works such as the construction of buildings, shipbuilding industries, aerospace industries, maintenance, etc.
How does it work?
I have said before that if you want to do arc welding, the required heat which we need is produced by an electrical arc.
It can be guided either mechanically or manually in the joint.
It can be a rod which simply carries the current or a special rod which melts as well and works as a filler material.
Basic circuit:
A basic circuit of arc welding is run by AC or DC power source. The needed control is connected with a hot cable to an electrode holder.
It makes an electrical connection with the power source.
Arc shielding:
Joining a metal needs more than just an electrode if you are doing arc welding.
Sometimes metals is react chemically in a high temperature. Sometimes doing so damages the strength of the joints.
Therefore arc shielding is done to protect the electrode and the melting pool from such damages.
This shield protects the metal from getting in contact with the air. This improves the quality of the weld.
Arc type:
An arc is an electrical current flowing from the cathode to the anode.
If the electrode is consumable, the heat of the arc melts the tips and the droplets are detached and transported of the arc column.
As the arc itself melts and becomes a part of the welding, it is called a metal-arc.
In this case, the filler material is melted from a separate wire or rod.
The consumable electrodes transfer the more generated heat into the melted pool.
As a result higher thermal efficiencies are found and also the existence of narrow heat affected the zones.
The type of current, the filler material, and the type of arc normally depends generally on the process, atmosphere, and the metal being melted.
Difference Between Gas And Arc Welding:
Here we are making a comparison between the two welding methods. These comparisons are basic but prominent.
Have a look at them, and you will get rid of your confusion after this.
1. Method:
The basic difference between these two types of welding is the heat generation method.
If you are doing arc welding, the heat is generated by an electrical arc of course by using electricity.
On the other hand, flammable gases are burnt to produce heat in the case of gas welding.
2. Temperature:
Arc welding generates high temperatures compared to gas welding.
Arc welding generates up to 6000 C, on the other hand, the heat generated from gas welding is 3600 C.
The better the temperature, the quicker the metals melt and you will get a stronger joint.
3. Durable joints:
Arc welding is capable of creating stronger joints than gas welding.
Even in the case of the ferrous joints, the arc welding wins.
The reason behind this is the high temperature
The high heat helps the metals to melt well and as a result, there are less risks of ruining the joints even if you are new at welding.
4. Filler material:
A filler material is used along with the shielding gas in case of arc welding.
If needed, a separate filler rod is used to do better gas welding.
Otherwise, there is no need of one in Gas welding.
5. Risk factors:
There are risk factors in both processes.
If you are doing arc welding a high voltage might do you harm.
In the case of gas welding accidents from high-pressure gases can do you the same.
In comparison, it seems that gas welding is the more dangerous one among the two.
You must take safety measures before you are doing welding, it does not matter what type of method you are using.
6. Production rate:
Gas welding has a lower production rate than the arc welding procedure.
7. Budget:
The initial cost of arc welding is more than gas welding. But, if you take a deeper insight, in the long run, gas is more costly than a welding rod.
Arc welding does not require any gas and this is why it can be considered as a cheaper deal to be done.
8. Efficiency:
Though both of the welding procedures have their own advantages and disadvantages, arc welding is found to be more efficient than gas welding.
There are more comparisons than this. But, these are the most prominent ones which will help you decide which one is best for you.
Advantages Of Gas Welding:
The reason behind gas welding having such fanfare is its huge scope of application.
The procedure is really easy to do.
It requires a low cost because there is no need for specialized machinery.
You do not have to be an expert if you want to do gas welding.
The basic ideas about welding are enough to make a good and solid joint.
As there is no need for specialized labor, as a result, the costing remains low.
Another good thing about gas welding is that it has a huge scope of application.
It is capable of welding non-ferrous and ferrous metals together.
As mentioned before, gas welding does not require any specialized machinery. As a result, the whole setup ensures portability.
The total melting and hardening process of gas welding is really low.
As a result, there is a low risk of any issues with hardening.
You can have control over the whole process.
The good burning of the gases ensures no root defects.
Having total control over the flow of gases also ensures a great welding performance as well.
Disadvantages Of Gas Welding:
As gas welding is not a “one-size-fits-all” type of welding method, it comes with some disadvantages too.
The disadvantages are listed below for a more clear understanding of the process.
1. Not for heavy metals:
Since the heat generated from gas welding is not sufficient for heavy welding, this is why heavy sections can not be joined economically.
So, if you want to weld the heavy sections of high strength steel it would be better not to do gas welding.
2. Time-consuming:
The rate of heating and cooling of the joints is relatively low. Though in some cases it is found advantageous.
3. Not for refractory metals:
Refractory metals such as tungsten, molybdenum as well as the reactive metals such as titanium can not be welded by the gas welding process.
4. Gets heat-affected:
Due to a long time heating of the joint, a larger area of the joint becomes heat affected.
5. ineffective flux-shielding:
Flux-shielding is not effective if you are doing gas welding. The oxidation can not be avoided no matter how much you try.
6. Hard to handle:
You might find it hard to ensure safety sometimes as the storage and handling of explosive gases are tough.
Advantages Of Arc Welding:
In this modern era, Arc welding has found its way to industries by dint of its benefits.
Major mechanical corporations are using this method to weld and they are really satisfied with it. Read the benefits mentioned below to find out.
1. Less time consuming:
The concentration of heat during arc welding is really high. This is why the metals melt easily and dries fast as well.
So, this turns out to be a really quick process.
It saves you a lot of time if you are doing arc welding.
2. Less distortion:
Because of the higher concentration of heat and high-speed welding, the arc welding produces few distortions.
During the welding, this is an important fact which decides which is the best method.
3. Consistent quality of weld :
Arc welding gives you a smooth finish and a neat appearance of the welded product.
4. No weather considerations:
Arc welding is a versatile welding process. This is why it can be implemented in almost every weather.
5. Less expensive power source:
Arc welding is a cost-friendly welding process. There is no need for extra budgets.
The machineries are cheap as well. Even the power source required is electricity. This is within budget as well.
6. Strong and durable joints:
The arc welded joints are capable of dealing with high impacts.
It does not matter if it has to bear high loads.
Due to the good impact strength, many industries are doing arc welding nowadays.
7. Corrosion resistance joints:
The weld joints are found to be corrosion resistant if you have done arc welding.
So, you do not have to bother about stopping the joints from getting affected by corrosion.
Because of such versatility and benefits, arc welding has gained a huge fanbase of its own.
The pros of it is what makes it one of the best methods available in the field of welding.
Disadvantages Of Arc Welding:
Though arc welding is full of advantages, some drawbacks make people choose other welding methods.
Though there are not many still they are given below for your help.
1. Less efficient:
Wastes are produced generally while doing arc welding. This is why sometimes it is found that it causes more costs than other methods of welding.
2. High skill level:
If you are doing arc welding, the operator has to be highly skilled about the method. Otherwise, it might turn into a huge mess.
3. Thin materials:
As the temperature originated from this welding is very high, this is why it becomes hard to weld thin materials by it.
The Winner?
Declaring a winner among the two welding methods is a tough decision to make. It depends only on your work requirements.
This decision depends completely upon you as you are the one who will be welding.
I hope the information above will help you to make an easy decision. Still, if you ask me, the modern the method is the better it will be for your work.
Thank you for your passion.
Have fun welding!