It depends! MIG welding gas comes in many different sizes and types. How long it lasts will depend on the gas and the size of the canister you purchase. If you purchase argon gas, for example, depending on the size you get, you may be able to get as little as 1 hour of use from it or as much as 12 hours of use!
It will also depend on variable factors such as the flow rate at which you set your regulator. Flow rate is measured in CFH (cubic feet per hour) and typically falls between 10CFH and 40CFH, depending on the job you are working on and the conditions you are working in. What we mean by this is that windy or draughty conditions may call for a higher flow rate (40 CFH), whereas if you were just planning on using the welder inside, you may need less flow rate (10 CFH, for example).
You can use an equation to work out how long your MIG welding gas will last. You simply take the cylinder volume in CFH and divide it by the flow rate which will also be in CFH. The sum of this equation will be the expected gas welding time in hours. For example:
A gas cylinder with 40 CFH used at a flow rate of 10 CFH could be expected to work for 4 hours. This is because 40 divided by 10 equals 4.
- Welding gas time = (volume of gas cylinder CFH) / (flow rate used CFH)
- Welding gas time = 40 / 10
- Welding gas time = 4
You can use the equation above to get a definitive answer on how long your MIG welding gas will last. This will be a more reliable way of working it out.
How long will a 20 CF argon tank last?
A 20 CF argon gas tank could last anywhere from 2 hours to 30 minutes. This exact figure will depend on the flow rate at which you operate it. You can expect a welding gas time of 2 hours if you run your 20 CF argon gas tank at a 10 CF flow rate. However, if you need a larger flow rate due to windy conditions and draughts, then you may only get 30 minutes out of your 20 CF argon gas tank (based on a flow rate of 40 CF).
Remember, a 20 CF argon gas tank refers to the volume of gas inside. In this case, the gas tank in question will have just 20 cubic feet (CF) of argon inside it. This is a relatively small amount and will be suitable for small jobs.
If you wanted something that will last longer and be suitable for bigger jobs, we recommend that you seek out an argon gas tank that has a larger volume such as 60 or 80 CF. you will then be able to make your gas last longer (depending on the flow rate you use).
It is important to use the recommended flow rate according to the type of gas tank you are using. Some may specify that it must not exceed a certain limit. This may also help to make the tank last longer.
What kind of tank do I need for MIG welding?
The tank you need for MIG welding will depend entirely on what you plan to use it for and for how long. In terms of the type of gas needed, you will likely find the most common choices are argon or a mixture known as MIG mix. MIG mix may include several different gases such as argon, carbon dioxide, and helium which is often added to increase the penetration of the weld.
Depending on whether you need a tank for welding at home or a hobby level, or for larger jobs such as those required by professionals, you may be able to get away with a relatively small tank size. It is common for home welding jobs to require 40 CF volume tanks, whereas a professional would likely choose 80 CF or even 120 CF depending on how long the job will take.
In general, the bigger the volume of the tank, the longer it will last. Of course, this will ultimately depend on the flow rate at which you set the tank. The higher the flow rate, the less time it will last.
Also keep in mind that, if the job in question is outside where you are exposed to the elements, then you may want to err on the side of caution and get a bigger tank since the flow rate will need to be higher. You can research to see how long your job might take and make your judgement based on that. If the job takes an hour, then a smaller tank at around 20 CF or 40 CF may be suitable.