How much Shield Gas?

[Boswell]

I have decided that I can't live without learning to weld. I just purchased a Hobart 210MVP MIG welder and I need to purchase a bottle of Shield Gas. I am thinking that my first project will me stand/frame to hold my longer metal stock. I am thinking to use square tube. probably 1/16th wall. I now need to purchase a bottle of Shield Gas (Argon/CO2). My question here is What size of bottle should I get? #2, #3 and #4 bottles are easily available. How many hours of welding can I expect to get from a #2( 40cu. ft) or from a #3?

Thanks for any suggestions

 

[tazzat]

Gas flow depends on the size of the nozzle. For the smaller 1/2" size nozzles you want generally 15-20 cf/hr.
For the larger 3/4" size nozzles you run about 25-40 cf/hr.

#2 @ 20 CFH give you around 2 hours of welding.

 

[Alexander McGilton]

Just going off my experience of ordering for the Concordia civil labs. If we were talking TIG, I would say the biggest tank you are comfortable moving. Maybe have a spare full tank in storage. The rental fee and deposit goes up linearly with the size of tank while volume goes up exponentially, the math is not exact but you get the idea that bigger is better. And especially for TIG welding of Al, you are just screaming out argon.

For mig, the Tank never seams to run empty, manly because the productivity is so much higher for the gas consumed, we don't have enough steel to through at the welder to consume so much to notice. So you can get a way with a more portable tank.

Though your greatest hurdle may be the delivery and return process. So what is the biggest cylinder you can pick up and put in your vehicle?

 

[Janderso]

I bought my tanks,
I don't like to run out so I bought the 330Cft for the Mig =75%co2 25% argon and for Tig I have the 244Cft 100% argon.
I need help to load and unload them = way too heavy.

 

[benmychree]

I have always used straight CO2 for mig; being as its a liquid charge in the cylinder, it lasts very much longer than gas mixtures and gets better penetration, the downside being that there is more spatter and the weld finish is a bit rougher. I have been retired for about 9 years now, and have not done a lot of welding, but I am still on the same cylinder of CO2.

 

[Janderso]

I had forgotten about that (gas seperation). The welding tips and tricks guy always "stirs" his tanks when he changes them.
So far, no issues.

 

[ericc]

One hour of welding goes by pretty quickly. You need to be decisive and move fast. I got along for quite a while with a 20 cu ft tank, but you have to be on your toes. And, you have to put up with running out on a weekend. With a larger tank, like 40 cu ft, things are much more relaxed. Even with two tanks, I am extremely sparing with TIG welding, using it mainly for tack welding before using the stick welder. With garage sale rods, nothing beats a stick welder, but if you're "on the clock" the MIG keeps you moving. Also, cost for gas is less per foot of weld. I'm not on the clock, and a lot of people who think they are really aren't.

 

[pontiac428]

If I were a beginning welder, I'd want a 150 cu. ft. bottle as a minimum. I'm not, so I have two each of the larger bottles in the range and can mix my own argon/CO2/helium (Smiths proportional mixers). I hate running out of gas, since it always happens on Saturday or Sunday (The Law of Murphy) and I can't get to the welding supply during the normal work week very easily.

 

[Ken from ontario]

I recommend buying your own bottle, a (Q-80CF) size Argon/co2 is only 30 inch high , a perfect size bottle to strap or chain to a small welding cart, not too heavy or too tall, holds enough gas to last a few training sessions and a few small projects. this is the smallest I would consider in a hobby setting.
Straight co2 (as benmychree said) gives great penetration but IMHO the Argon/co2 might be a better choice for someone who is just starting to learn.

 

[Cadillac]

I second the largest tank you can handle. And have a backup never fails you’ll run out in the middle of a project.