As important electrodes are for stick welding, so are shielding gases for MIG welding. You need to be aware of which shielding gas to use and how much to buy and where to buy from if you have decided to take up MIG welding. It is always better to know the basics related to choosing the shielding gases so that you can take care of the situation if something goes wrong.
There are a lot of gases that you can use for MIG welding and they can be further mixed together to create different qualities and properties. In general, you can expect to spend $150 to $350 dollars on a new full tank of shielding gas. For example, 40 CF Argon 75/25 CO2 costs roughly $150-170.
DIFFERENT GASES USED IN MIG WELDING
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There are quite a few gases that can be used with MIG welding, especially if you take into account the different situations you can use these gases in. let’s take a look at the most common ones which are being used around the world.
CARBON DIOXIDE
I think this gas might be the most commonly used all around the world, there are a few reasons for this. The first and I think the most important one would be its cost, it is considerably cheaper when compared to gases such as argon. The other reason is the fact that it can be used without any inert gas. This adds to its overall quality of being cost-effective.
You should probably use CO2 if you are looking for a cheap gas that can get the job done. It’s not ideal if you want to make super clean welds. On top of this using CO2 can also lead to a lot of spatter while not being able to form a stable arc, CO2 should also be preferred if you are working with thicker metals.
Overall, it does get the job done, and because of the price, CO2 is what I’m using.
ARGON
Argon and CO2 blend is a highly recommended shielding gas among welders. Using argon can result in pretty stable and fluid arcs. It is also used in its pure form when dealing with non-ferrous metals such as aluminum. The most common gases with which argon is mixed are hydrogen, helium, and oxygen.
Argon is regularly mixed with CO2 to increase the arc strength and to reduce the spatter when compared to using 100% CO2. Different argon blends are also used for welding metals such as stainless steel and carbon metals.
OXYGEN
Oxygen is mostly used while mixing with other gases, most commonly argon in small quantities to enhance some of the characteristics. It can be used to enhance properties such as penetration, weld pool fluidity, and arc stability. Oxygen and argon blends are mostly used on stainless steel and low alloy metals but not at all on aluminum, copper, and manganese because of their increased chances of oxidation.
You can read more about argon-oxygen blends here.
One place where high oxygen blends shouldn’t be used is when you will be welding in odd positions as oxygen increases the fluidity of weld pools.
HELIUM
Helium can be used in a lot of jobs that involve non-ferrous metals and stainless steel. This is also particularly preferred in jobs requiring deep penetration. The most common gas it is mixed with is argon and sometimes additional CO2 is added to make the gas work better on stainless steel.
Helium is also preferred because of its increased productivity, this is due to its hotter arc formations which can result in faster travel speeds. But one factor which plays against using helium is its higher cost and higher flow rate. These both factors can double down and can be pretty hard to source for a lot of casual users.
Some other gases which are sometimes used are hydrogen, propane, and nitrogen. All three of these gases are used in specific circumstances, for example, hydrogen can be used while working in high-temperature jobs. While propane is usually used in scrap metal yards where the looks of the cut or the weld don’t matter.
DOES WELDING GAS GO BAD
This question troubles a lot of people who are not going to be welding every single day or for those people who are just hobbyists who will only sometimes weld. you don’t want to spend a lot of money on welding gas if it will go bad quickly.
One thing to know is that welding gas has a pretty good shelf life and it doesn’t necessarily go bad, one thing which might happen is that the gases can separate if you are working with mixed gas.
Since I only use CO2 for my projects, I have not run into this problem. What I have experienced is that going into the workshop just to discover that my shielding gas bottle is empty. It leaked empty because the gas solenoid of the welder was not holding. Could have been easy to avoid that by closing the main tank valve. So as a tip, I would recommend closing the main valve every time you’re done welding.
CAN YOU MIG WELD WITHOUT GAS
The name itself stands for metal inert gas, I guess you can tell by the name of the technique about the answer to this question. Actual MIG welding cannot be done without gas. There are some methods out there that are referred to as gasless MIG welding but in reality, they are a hybrid between stick and MIG welding, also known as FCAW.
These methods use a flux core wire which is self-shielding so you don’t need a shielding gas to protect the weld from atmospheric contaminants. The gas is still being produced, it’s just that you are not supplying it. Using this type of method won’t require you to carry a cylinder around with you all the time.
HOW MUCH DOES MIG GAS BOTTLE COST
There are two major factors that affect the cost of welding gas, the size of the cylinder you are going to need and the type of gas you are buying. Usually, gas cylinders come in three sizes, 40, 80, 125 CF. There are bigger sizes out there but they can be sourced by special orders or they are leased to the clients by the stores.
Now depending on the type of gas and the mixture you are using the price of the gas can go up as high as $350 per bottle. Argon 75% 25% CO2 You can expect to pay around $150-170 for a 40 CF cylinder. The most expensive gas you can get is probably argon, this is one of those reasons why it isn’t used as much.
As for the refills, they are not as expensive as buying a new bottle. For the smaller bottles, you’ll probably end up spending $20-50 per refill.
Here is a link to 125 CF 100% Argon cylinder that’s available on Amazon. You can check the current pricing.
Here is another one, Argon/CO2 80 CF on Amazon.
They are both affiliate links.
HOW TO TELL IF MY SHIELDING GAS CYLINDER IS EMPTY
Most of the gas regulators which you will be using will have a pressure gauge on them. Make sure these gauges are working correctly when you are using them on cylinders and keep an eye on them when you are starting your weld. Avoid any leaks.
Markdown the pressure of the tank when it is full. When you use the shielding gas, the pressure drops in the bottle. If it has dropped by half, you roughly have used half of it. You’ll know the bottle is empty once the gauge goes down to zero, or once your machine stops feeding the gas while welding.
HOW LONG DOES WELDING GAS LAST
The answer to this question depends on a lot of factors, some of them include the fact that how much are you going to weld and what is the flow rate you are working with. Keeping all of these things in mind, the average time a cylinder of shielding gas lasts for a casual welder is about 5-6 days.
I have reached this number taking into account if the average flow rate is about 10-20 CFH and you are going to be using a cylinder with a capacity of about 250CF, according to these assumptions your bottle will last about 20 hours welding.
You can read about correct flow rates on my post here.
WHERE CAN I BUY WELDING GAS
The two that come to mind would be TractorSupply and Airgas. If you do not have these two in Your area I would suggest asking your local hardware store if they have the welding equipment. One tip I can give is to ask around a warehouse or a workshop that does regular welding work, they usually have a good idea about where to source your welding gas from. Also, make sure to look around online.
CAN I REFILL MY OLD BOTTLE AND HOW MUCH DOES IT COST
Technically you can, but practically it depends if your welding gas provider will do it for you or not. I have heard about a lot of places that will refuse to refill your cylinder but they will only replace it for you. This can cost a bit more when compared to refilling but is still a lot less when compared to buying another new cylinder.
As I said earlier, the refills do not cost as much as buying a new gas bottle. You can expect to pay around 30-50 bucks for the smaller bottles depending on your supplier.
FREQUENTLY ASKED QUESTIONS
Which gas to buy and where to use specific gases can be pretty confusing if you are new to the world of welding, that’s why it is important to get your basics cleared. I will try to answer some of the most common queries that people have about shielding gases.
If you inhale small quantities of argon it won’t harm you, but if you are working with argon and there is a leakage in a closed room with no ventilation it is entirely possible that you will suffocate because of lack of oxygen.
During the beginning of your welding journey, you will end up making the mistake of buying either too much or too little welding gas. You can try making an educated guess depending on your requirement but this is one thing which you properly get through experience.
As the name suggests reactive gases go through changes and bring changes when there is a change in temperature or when they come in contact with other substances while inert gases stay the same throughout the entire welding process. reactive gases are used when there is a need to enhance the way metal is being fused.
CONCLUSION
To sum it all up, welding gases can be mixed together to enhance a lot of properties and sometimes even to save costs. There are usually three different sizes of cylinders you can buy depending on your need, the larger cylinders can go for as much as $350. Depending on your usage one single cylinder can last for up to 20 hours of usage. There are some special techniques to store some specific gases otherwise they can separate.