MIG Welding: Which Gas, and How Big a Cylinder? (1 Viewer)

[geocrasher]

Hey everyone,

It's been quite some time since I've posted here, but there's not a community I trust more for questions like this

I've been stick welding for a few years off and on and I just picked up Yeswelder 205 DS and intend to use it for MIG welding. I'm shopping for a cylinder of gas and got a bit of sticker shock on a 55 cu ft cylinder, filled, being over $300 locally. And a friend thought such a small cylinder might not last very long... I don't expect to do a lot of welding. I don't have continuous projects, just stuff here and there. Is 55cu ft a good size for a hobbyist who welds less than a few hours a year at my current rate?

To keep costs down I thought about buying an Argon/CO2 cylinder on Amazon and swapping at the local welding shop. They even suggested it as an option.

I also have a 20# CO2 bottle I can exchange for a filled bottle for only $40. I know CO2 MIG is possible, but is it realistic to get the same utility out of straight CO2? For a beginner MIG welder, is it a bad idea?

And has anybody got experience with the <$30 regulators?

Thanks for all the help. I sincerely appreciate it.

 

[e9999]

I'm not an expert welder but I think CO2 is a great way to go. Much cheaper to get the gas refilled locally for me (I go to a beverage supplier place) and gives better penetration than mix from what I saw. Maybe not as clean a weld (not sure) but I don't think it matters for my level of welding anyway. As far as I can tell, the bottles themselves can be the same but the bottle valve and regulator nipple are different. Those are easy to change yourself and I think the regulator itself does not care whether it's CO2 or mix. But a pro will set me straight if needed.

As to the buy and fill vs exchange, you'd want to check what your local supplier is fine with cuz I think some won't do refills, just exchange.

 

[Waorani]

Got a couple of friends in the welding supply business. Gas cylinder rental fees are a big part of their income and many are reluctant to sell. I bought an 80CF AR/CO2 tank 20yrs ago just because I didn't want to rent. Don't remember cost but wasn't too bad. Went a couple months ago to try to buy another to save shuffling one tank around and cost was close to $400 w/ tax.

I've got a couple of full CO2 cylinders left over from kegerator days and will probably try those next time I run out. And places around here only swap tanks, refilling is done elsewhere.

 

[Broski]

I always use Argon/C02 Mix in my Mig and think it's the better way to go especially for a beginner welder.
I also think you will be fine with a smaller tank

 

[PIP]

Owner tanks are generally exchanged, although I have heard of places filling tanks, but have never seen it anywhere I've lived in the USA.

When you buy an owner tank you own it. and can exchange it for the same size cylinder of any gas you want. You can buy a helium tank and exchange it for a nitrogen tank. They don't care.

If you buy a tank of a certain size and you want a bigger tank you can pay a few bucks and upgrade to whatever size you want. I find it's surprisingly little to upgrade.

Gas suppliers really take advantage of guys with the small tanks. The gas doesn't really cost anything. You're just paying for the transport and wages and building, etc. so if it were fair a 20cu ft tank should only be about 25 cents less than a 330 tank. That's not how it works though and they charge WAY more for the little tanks because hobby guys don't have any clout to argue.

120cu ft is the smallest tank I would recommend. 250 cu ft K tanks are best for me. You get hosed on gas prices for anything below a 120 bottle and anything smaller runs out real quick.

Another thing- You really need 2 bottles. You never run out of gas at a convenient time.

At my local independent gas supplier I can bring in a 20cu ft CO2 tank and exchange it and $40 for a K tank. If I buy the tank outright from them it's like $300!

So buy a used owner tank off craigslist or marketplace for a few bucks and exchange it for what you need.

Be very careful not to buy a rental bottle! If anything is written on the neck flange it is likely not an owner bottle. The neck flange I'm talking about is the uppermost part of the bottle you can see with the cap screwed on. If there are any raised letters on that flange there's a 99% chance it's a rental bottle. If you buy a rental bottle you cannot legally own it, it's property of whoever's name is on the bottle.

Also check your bottles every time you exchange them! I had to go to war with Airgas because they exchanged my owner K tanks for rentals because they didn't have any owner K tanks and the guy just assumed mine were rentals.

75/25 is the normal gas for beginner general purpose MIG welding.

 

[e9999]

another thing to keep in mind is that if you buy a bottle, it will have an expiration date after which it can't be refilled any longer without recertification. I have a like new bottle that I had refilled only once and it has now expired, that is a bummer. And there will be a fee to have it tested again, of course. It should be less than buying a new one but is a pain to arrange if you actually want it back rather than just an exchange, so a potential issue. So, buying a bottle with little expected use may not be a great move, cost wise. I would also be careful that if you do exchanges and get an old bottle, that you return it before it expires or I suspect they may ask for a fee (not sure how that works TBH). OTOH, I would factor in the difference in cost between CO2 and mix, I suspect it is substantial in most places. Last time I had a CO2 bottle refilled it was like $15 or $20. Not at a welding supply place, though. It is nice that with CO2 you have more choice of locations to get your gas. My experience does not suggest that all local welding shops are very DIYer-friendly.

 

[geocrasher]

Thanks everyone for the input. The more I look at it, for as little as I weld, I think I want to start with CO2. I don't think that it's a bad way to go, because AR/CO2 will only be easier, should I upgrade. And the same regulator etc can be used. And there's the added benefit of being able to use the CO2 tank for other things. 20lbs might be a bit big for a portable tire inflator though

 

[PIP]

Bottle expiration does not matter when you exchange bottles. Nobody cares.

 

[e9999]

^ Not experienced that issue either way myself but have a friend who was charged a fee cuz he exchanged an older bottle. Must depend on the place. Or he was taken advantage of.

FWIW, I just looked and saw that you can get a 15lb recertified (not new) CO2 bottle for $70 (+ s/h I'm sure) from brewer supply stores online. That could be an option, I suppose. Not very big, but if you weld little, could last a bit, and way easier to move around.

 

[Waorani]

After the comment about Amazon cylinders I took a look. Some of the comments reference no DOT stamp and that being a possible issue in some states.

 

[aztoyman]

You will be fine with CO2. Something to be aware of is that the machine settings will be different when using CO2 or Argon mix, even with the same size wire and thickness of the steel you're welding. One of my machines had a basic setting chart inside the cabinet door for both gasses.

With CO2 the welds tend to be flatter and you get more spatter than with Argon mix. Basically speaking, the heat is affected. I prefer CO2 with a small machine like a 110 volt unit. I use Argon mix with my larger machines.

I have used the cheap flow regulators and I do not recommend them. I've had 3 and they all failed in a little over a year. And they all had slow leaks which wasted gas. The first flow regulator I ever had was a Victor that I bought in 1987 and it's still working. I replaced the cheap Chinese one with an American made one from Harris that is easily found on sale for under $100. I got mine for $80 to my door around last Christmas. I have a brass adapter that allows me to swap them to a CO2 tank.

Harris 601 CO2 Flowmeter Regulator 601-CD-320

Harris® 601 CO2 (Carbon Dioxide) Flow Meter Regulator 601-CD-320The Harris® 601 CO2 Flowmeter Regulator is ideal for medium and light duty MIG welding applications where more precise control of the carbon dioxide shielding gas flow is desired. The 601-CD is economical, compact and comes with a 7...

store.cyberweld.com

Looks like it's made in Poland now. 7 year warranty

 

[geocrasher]

Thanks again all. I have a HF card so I'll just pick up this guy:

CO2/Argon Flow Gauge Regulator

Amazing deals on this Co2/Argon Flow Gauge Regulator at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Then $40 later I'll have my CO2 bottle and can get going. I know it won't be as good as AR/CO2 but it'll be a lot better than stick, all the same. It just feels right. I can afford the AR/CO2 setup, but I'd rather not spend money I don't absolutely have to. It can be next year's expenditure if nothing else

 

[PIP]

Thanks again all. I have a HF card so I'll just pick up this guy:

CO2/Argon Flow Gauge Regulator

Amazing deals on this Co2/Argon Flow Gauge Regulator at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Then $40 later I'll have my CO2 bottle and can get going. I know it won't be as good as AR/CO2 but it'll be a lot better than stick, all the same. It just feels right. I can afford the AR/CO2 setup, but I'd rather not spend money I don't absolutely have to. It can be next year's expenditure if nothing else

Nothing wrong with stick. Stick welding is a far more capable process than hard wire MIG.

The biggest problem with MIG is how easy it is to make a terrible weld that looks pretty.

The current trend of "tack stacking" MIG welds is an extreme example.

 

[geocrasher]

Nope, nothing wrong with stick. I still love my stick welder, and the new welder can do stick too. But MIG is a lot better on thing stuff, which is something I want to expand to. Body work etc.

And can you elaborate on what you mean about the "tack stacking" of MIG welds being a bad trend? I see it used to tack things together and fill in the gap or whatever and then go back over it with a solid bead. Is that not correct?

 

[PIP]

Nope, nothing wrong with stick. I still love my stick welder, and the new welder can do stick too. But MIG is a lot better on thing stuff, which is something I want to expand to. Body work etc.

Definitely true. Stick does surprisingly well down to 16g exhaust, but bodywork is no good.

That does beg the question though- Why are you buying CO2 for welding thin body panels? 75/25 would definitely be superior for that.

 

[aztoyman]

Argon mix is definitely better on sheet metal.

Pay close attention to the flow regulator. My Chinese ones all trickled gas constantly.

 

[e9999]

I would not hesitate to buy and use a hammer from HF, but I would be very hesitant to use something from them that involves 3000 psi of pressure....

 

[geocrasher]

So, I'm buying CO2 to learn MIG on the cheap. I could use my stick welder for my current project, but that's not the direction I chose to go. As for the regulator, it gets far better reviews than the sub-$30 junk on amazon.

When I get ready to do body work, I'll upgrade to AR/CO2 for sure.

 

[Broski]

JMHO
For me the idea with MiG is to get a cleaner looking weld with Less slag.
Welding with straight CO2 negates that.
MIG also need a controlled environment ( no wind) where a stick welder doesn’t care.

 

[geocrasher]

Dammit, you guys and your peer pressure...