Welding with Argon/CO2 vs CO2

[brainbug007]

I recently bought a bottle of argon/co2 mix of the bay as there wasn't any pure co2 going at the time. It's the 1st time I've used it and it seems to affect the power settings compared to co2? On my normal setting (3/6 power, 4.5 speed) it almost seemed really hot and about to blow holes and looked sounded the same as when i was using co2 on 6/6 power with 5 speed for really thick plate?

[Talonmotorsport]

C02 in mig welding acts to shield the arc and the weld pool from out side contaminants, it's not a great inert gas but it's cheap. 100% Argon is used in tig welding to give a very stable arc but is around 2/3 more expensive. Basicly the more stable you can get the weld pool (molten material to which the filler is added) the better penetration and stronger the weld is. 10-15% Argon mixed in to C02 will stablise the arc between the filler wire and the weld pool during welding, it means the weld will be cleaner as the filler rod will effectivly become more fluid like a stream of water from a tap rather than a dripping one. I hope this makes sense to some one :rolleyes:

[ozzy1]

I got argoshield light that i use and gives real good welds,about70quid for an E size bottle and lasts bloody ages.Although i cant compare it to Co2 as this is all ive used :D

[andysredmini]

Not sure how it affects the power settings or the weld but I was told by our welder at work and by the welding store we use that Co2 welds hotter than a Co2 argon mix.

[baz-r]

only low co2 content mixed gas is any good for light miging (light ie sub 6mm) as you go up in thickness its better to up the co2 content a little
the co2 effects the arc stablity
somtimes even other gasses can be added in the mix like helium and others
its a real complex affair but all we need to know here is low co2/argon mixed gas for light mild steels and pure argon for stainless and alloy

only thing i would use co2 for is realy thick plate on realy thick wire and a realy big welder otherwise its not nice to use
see below:cool:
http://www.proweld.co.uk/assets/images/mig%20gasses.jpg

[flyerncle]

Straight Co2 does give hotter welds but is controlable with a little jiggling of the settings,at £12 a bottle from local beer supplier I cant complain too much.

[rapidtornado]

whilst on the subject of CO2 bottles I have managed to 'borrow' a bottle of CO2 from a friendly pub landlord, just wondered if the regulators that fit these bottles are all the same as £30+ for a regulator is an expensive mistake if you buy the wrong one... thanks ;)

Rapid

[ozzy1]

As far as im aware they are a standard size the only variation is left hand or right hand thread.I think Acetylene is the left hand thread from memory.
(If the bottle fits in your boot why not take it along with you just in case then you can always cart it into the shop,unless your buying online of course)

[Talonmotorsport]

Pub type C02 bottle regulator has a plain nut that screws ON TO the threadhttp://www.ebay.co.uk/itm/Co2-Gas-Regulator-Two-Gauge-4-Bar-Side-Entry-/160677697823?pt=LH_DefaultDomain_3&hash=item256923191f

Industrial big bottle type regulator has a CONE SHAPED fitting the screws IN TO the bottlehttp://www.ebay.co.uk/itm/ARGON-GAS-WELDING-REGULATOR-TWIN-2-GAUGE-SINGLE-STAGE-/190533461764?pt=LH_DefaultDomain_3&hash=item2c5cade704

You can also get a brass adaptor to make the industrial regulator fit the pub bottle if you can find them.... It's also worth using some ptfe tape on the adaptor thread to make it gas tight instead of trying to over tighten the thread.

[Wynand]

I think Acetylene is the left hand thread from memory.


Quite correct mate.
In fact, all fittings and nuts on acetylene equipment is left hand thread and furthermore marked with a groove cut on nut/fitting for identification to prevent accidental connection to the oxygen side...

[rapidtornado]

Thanks for the info and link, much appreciated!

[PorkChop]

Pub type C02 bottle regulator has a plain nut that screws ON TO the threadhttp://www.ebay.co.uk/itm/Co2-Gas-Regulator-Two-Gauge-4-Bar-Side-Entry-/160677697823?pt=LH_DefaultDomain_3&hash=item256923191f

Industrial big bottle type regulator has a CONE SHAPED fitting the screws IN TO the bottlehttp://www.ebay.co.uk/itm/Oxygen-Gas-Welding-Regulator-Twin-2-Gauge-Single-Stage-2066-GC000-/400242290941?pt=LH_DefaultDomain_3&hash=item5d304cb0fd

You can also get a brass adaptor to make the industrial regulator fit the pub bottle if you can find them.... It's also worth using some ptfe tape on the adaptor thread to make it gas tight instead of trying to over tighten the thread.

I'd just like to point out that tape should only be used on tapered threads. If you need to put tape on a straight thread, then the fitting isn't seated correctly. Straight fittings don't seal on the threads. A tapered thread without tape is more likely to leak.

[Trophy Blue]

CO2 is added to pure argon to increase penetration, CO2 on its own will burn into the parent material, but will produce a brittle weld.

[flyerncle]

Some top end regulators as the Siegen one I have will fit both types of bottle.

[robo]

Cant see why anyone would want to use anything other than the correct gas. I once used the argon bottle off the tig on the mig when the mig bottle ran out and the weld looked crap.My mate insists on using pub gas on his mig to save money and those welds always look like they have been frazzed.

Bob

[baz-r]

Quite correct mate.
In fact, all fittings and nuts on acetylene equipment is left hand thread and furthermore marked with a groove cut on nut/fitting for identification to prevent accidental connection to the oxygen side...

all fuels are l/h (have a notch at corner of nuts) oxy and innerts are r/h threads
regulators should always be marked for type of gas and never mixed as its very dangerous (like acetlyene over pressurised out of its acetone will explode its a very unstable gas and can burn on its own with no oxygen!)
saying that co2 and argon can be swaped but purge out co2 for when using pure argon
pub bottles have a diffrent fitting to industrial cyl


also oxy equipment should be kept totaly oil and ptfe free as can burn internaly thats verry unsafe!

[robo]

Some top end regulators as the Siegen one I have will fit both types of bottle.

We have used the oxy gauge on the mig bottle before now with no problems.

bob