View Full Version : What gas are you using on your MIG welding?

04-11-2014, 06:32 PM
One for UK folks mostly I think.

My little hobby-mig welder (CLARKE 105EN) came with a tall CO2 bottle which (according to the dial) still has a fair bit of gas left in it (showing >100BAR on the pressure gauge).
The instructor on my welding course was very dismissive about what he termed "PUB-GAS" and said it was no comparison to Argoshield or Cougar mixed gases when it came to weld quality and cosmetic appearance (spatter etc.).

Now, spatter I can remove with a flap wheel or grinder, but "weld-quality"?

As and when this bottle does run out and I need to replace it, what are all you UK folks using (typical cylinder size, gas-mix, contract/no contract etc.)?

There seems to be a few dealers on e-bay offering the same as Argoshield (mix percentages) in 9Litre & 20 Litre tanks-sizes, are they any good do you know?
Thanks in advance for your time and your informed opinions.



04-12-2014, 02:24 AM
Dan - have only used argon and some mixed variants of the same, but never CO2. Why not just do some test welds - must be the best way to see if it's OK, and for hobby welders you don't need anything too fancy. At the very least it can't be as bad as flux-core MIG, that stuff always looks awful to me.......

04-12-2014, 04:06 AM
He is right to be dismissive :cheesy:
CO2 will run hot and will affect quality of weld, however it is not impossible to use it ... and if you budget is tight - just use it.
Bottle pressure is no indication of content left - it will remain high until the bottle is empty.
I would avoid ebay - there are better options.
Do your homework here (http://www.mig-welding.co.uk/forum/) and you will find local/UK based advice that's very good (including sources for gas)

ps I am running non-rental (deposit) bottle of Argon + 5% CO2

04-12-2014, 04:32 AM
Danny, I realize that I'm not in the UK, but this page from Miller shows which blends of gasses to use in which situations: http://www.millerwelds.com/resources/tech_tips/MIG_tips/
Note that the info is in section 4. It is small compared to the rest of the charts and info on the page.

For our purposes everything I've seen related to MIG in the US for the gauges of mild steel that we tend to use puts us in the 75% Argon / 25% CO2 mix. We use 100% Argon for TIG or a blend with Helium in some high heat scenarios for Aluminum. Especially if welding Aluminum on DC.

I looked up the Argosheild and it looks like the closest it comes to the 75/25 Argon/CO2 mix is their "heavy" mix which is 78 Argon / 20 CO2 and 2 Oxygen.

I found a breakdown of the "Coogar" blends and "Cougar 20" (Note the name change for the line versus the blend) has the same 78/20/2 Argon/CO2/O2 blend.

Either one of those should be better than plain CO2 which Miller lists as a good penetration gas for steel, but probably too hot for thin steel. Over here generally 3mm is considered the beginning of the "thin" range. However there apparantly is a market for small CO2 bottles on portable field MIG welders. Not sure how long it is going to last though because apparently the welding community here isn't showing much interest.

Over here we also tend to use 80 CF tanks which over in the UK looks to be your Argoshield X tank at 2.42 Cubic Meters

Hope this at least helps you understand the differences between the gasses.

Enjoy your weekend,


04-12-2014, 04:40 AM
Hi Danny

I am still using the baby bottles of gas , get through about 1.5 bottles per trike which makes it expensive
tried both on mild steel and happily weld with both CO2 and the argon mix , what makes me decide which I buy is what is on the shelf when I run out :taz:

regards emma

04-12-2014, 05:30 AM
Thanks everyone (Frank, Bambuko, Bill & Emma),
I think I may switch to a Gas-Mix then. There appears to be a reasonably local stockist where they offer a rent-free 9Litre bottle for £85, with refills at only £30 (you get your£55 back when you finally ditch the service and return the bottle).
This sounds like a very reasonable deal to me.

I have heard of a BOC/AL deal where they charge you considerably more for the tank and the refills are about £37 and the refill is effectively a swap-out and each tank comes with inbuilt regulator and flow-meter, so I will look there too.
As bike #2 will NOT be the 2.5mm steel heavyweight but an anorexic 1.5mm I will need all the help I can get. :)

Many thanks,


04-12-2014, 01:29 PM
Hi Dan, back from the frozen north and catching up here, the cougar 20 is what I use, I believe there is a company that sells decent size bottles at 80 squids deposit and refundable with no rental contract, will look them up later

04-12-2014, 02:48 PM
Be careful Dan - not all hobby MIG welders are equipped to handle the "proper" bottle .
You might have to modify it by adding gas valve (see here (http://www.weldequip.com/gas-solenoid-valve.htm))

04-12-2014, 05:40 PM
Hi Bambuko,

I believe it should be capable as it is the "Gas Ready" version of the CLARKE 105EN, and I can't see that they would sell it if it was incapable of handling a regulated gas supply safely.
AFAIK it is the job of the regulator and associated flow-valve to ensure that the amount of gas leaving the bottle and arriving at the shroud is the correct CFM rate and not the full pressure of the bottle.
I do understand the terrific amount of energy within a full gas bottle at 100 - 230 Atmo's. :-)
But thanks for the warning and the link, you never know, it might be required, I will double check everything.



04-12-2014, 06:20 PM
The nice thing about a swapout rather than an ownership deal is your not responsible for the required 5 to 10 year hydrostatic test of the bottle. This test is done to verify the strength of the bottle does not expand when filled. I don't remember the allowed expansion. However if it fails they drill big holes in the side of the tank and toss it to recycle. And you are out the money. My bottle is considered purchased but it gets swapped. Thus I am not responsible for the hydrostatic test. Sort of the best of both worlds. Just food for though. Not sure if UK has the same requirement. Here in USA it is a function of our Federal transportation Department. Can't have bottle blowing up on our roads I guess. I'm sure you will like the CO2/Argon mix. Have fun with the biggfer bottle.

04-13-2014, 02:42 AM

I have a deal like that for my Argon , no rental just swap when empty worked for me so far.

Do you have a nozzle flow metre ? just a ball in the tube but far more accurate than the supplied gauges saves a ton of gas.


04-13-2014, 05:39 AM
Hi DTD & Paul,
Thanks for your responses, much appreciated.
It was the introduction of the un-rented exchange bottle service by people like Adams Gas that broke the BOC/Air-Liquide monopoly in the UK I think DTD. :-)
Very interested to hear that the simple floating ball/pea gauge is more accurate than the dial gauges Paul, I would not have expected that (it being so simple).
More to ponder.



04-13-2014, 06:01 AM
Morning Danny
I have just woke up - been up for hours but just woken up and getting human ( NO COMMENTS thank you )
here is another two pennyworth .

If you have a small adapter for the baby bottles of gas , then why not do it the easy way get a bottle of argon mix and try it , not quite as good as the try before you buy but cheaper than the invitation of just come down here again and have a go with a bottle of co2 v argon mix with my little snap-on welder .

have a good weekend

regards emma

04-13-2014, 08:20 AM
Hi Emma,

I can indeed have a try-out of a disposable to assess the difference.
It is very kind of you to offer a "trial-run" at your place, but if truth be told the cost of the round-trip fuel is almost the equivalent of an exchange tank. ......Eeeekkkkk!
It is also interesting to see that the CLARKE manual for the welder recommends CO2 for Mild Steel and "mixed-Gas" for thin sheet metal (Mild Steel or Stainless). I think 16-Gauge tube qualifies as "Thin Sheet" TBH. :-)

Emma, If I do take the plunge & buy a bottle etc. for Mixed-Gas, would you want to come up here for a visit and "lift" my CO2 bottle? ;-)



04-13-2014, 08:48 AM
Thanks Danny

that's an offer I cannot refuse

regards emma

04-14-2014, 04:20 PM
I've used co2 for all my welding and can confirm it's "good enough". I've welded cars, trailers, gates and bikes with it. Every user of argon says it's better but it's finding a local supplier that's the issue. As well as welders supplies shops try brewers supplies, paintball sites and even hydroponics shops for co2. I get a pub sized bottle exchanged for £16 at a local hydroponics shop. Co2 is liquid in the tank and will typically exert 850psi from full to empty. This will vary considerably with temperature. The only way to check what's left is to weigh the cylinder which requires the weight of the empty one and there's a great variation in them. Give it a lift and a slosh around for a guestimate. Best bet is to have two bottles and swap each one as it becomes empty. It's a given that one bottle will run out with a couple of inches of weld left to do on any project.

See if you can get a local argon supply before testing it via a disposable. If you can't get it locally in a bulk tank then you'll be stuck with disposables.

The Clarke will take any co2 supply so long as the bottle has the correct regulator on it. The regulator for the disposables won't fit the pub or full sized bottles.

05-05-2014, 12:21 PM
DannyC,...........When I used gas at work (high school maintenance) I used CO2 bottles which we obsconded (because my boss was cheap) with from the pop machines (calfateria/football snack bars)...........Worked good even on thin stuff (welded 1000s of desks with it)............................................... .................................................. .................................................. .........At home I have a argon Co2 mix, but am thinking of a strait argon when I trade it in as I got a Tig & will share the bottle between the two...............wonderer........................ .................................................. .................................................. .................................................s tormbird,....never seen a nosel flow meter...............Cool....................wonder er