Using CO2 gas with a mig welder instead of Argon

[Sam_Q]

I have recently seen a mig welder advertised that it comes with a regulator to use carbon dioxide gas instead of an argon mix for normal steel welds. The regulator has a built in 240V heating element to stop it freezing up.


Anyone know or have used anything like this.


- Sam

[assassin10000]

Never heard of one with a heater built in. You'd have to be using a lot of co2 fast to need a heater in it. My friend is a professional welder (welds awnings/ceilings/roofs) and uses straight co2. None of his or the shops equipment runs a heater on their co2 bottles.

Think about this, fire extinguishers blow through co2 stupid fast in comparison to the flow rate needed for welding. And they don't have a problem.

Andrew

[Sam_Q]

so do you know the advantages/disadvantages of it?

This one page said the heater was only for cold days but its nice to know I probably wont have to rely upon it

BTW fire extinguishers are different, theres a metal part on the line just before the nozzle you hold, I have been warned that if you hold that part your hand will be frozen onto them.

[assassin10000]

Yeah, I know extingishers are a little different, but it was just as an example.

Running straight CO2 is fine afaik. It just means you will have a slightly hotter weld IIRC. I'm no expert tho, instead I'd talk to a local welding supply shop. Or checkout the welding forums.

Andrew

[af300e]

I understand it to be mainly for light material. As far as I know, argoshield gas is a mix of argon and CO2 at something like 4:1. I'm with Assasin on the heaters, 20L/min should not freeze. Any liquified gas under pressure absorbs heat when released/vaporised, so argon would freeze too if the flow was right.

Also heard it spatters like a bitch, arc is less steady than with argon based gases and you may need a different mig wire, but I don't have any first hand experience with it. It's been around for a while, like 30 years?

[wilbo666]

http://www.mig-welding.co.uk/welding-gas.htm

Another internet opinion

Cheers
Wilbo

[takai]

From my use its better for light material, as you can get a hotter arc with a lower amperage.

However it does splatter like all hell,

EDIT: meant to say that be sure your welder can go low enough. My WIA could only go down to 18v, which even with 0.6mm wire and CO2 was too powerful to weld sub 0.4mm.

[assassin10000]

Light material? Hell, my friend welds steel thats 1/2" thick for giant metal awnings... They run straight CO2 at his work.

TIG on the other hand is a whole different beast.

Andrew

[af300e]

I was talking about mig, I know it can be used on heavy material but I understand that it is more common in light fabrication. I have no first hand experience, only heresay.

[ONCE-NA]

As I understand when using C02 it deposits carbon in the molten steel resulting in a harder weld, compared with a completly inert gas (Argon). Thats why you cant use CO2 or ArgoShield (C02/Argon mix) when welding stainless or particulary alluminium.

[Ben Wilson]

http://www.mig-welding.co.uk/welding-gas.htm

Another internet opinion

Cheers
Wilbo

I've never seen that site before, thanks +rep

[takai]

Light material? Hell, my friend welds steel thats 1/2" thick for giant metal awnings... They run straight CO2 at his work.

TIG on the other hand is a whole different beast.

Andrew

Not saying you CANT do it, but more that in my view its more suitable for lighter gauge. Mainly because you can get a smaller weld out of it.

From what im led to believe its more stable in windier conditions, although that could be complete hearsay.

[Sam_Q]

looking at the pics on that website it looks like the welds end up real shitty, or atleast on larger welds.

Chris what are you welding thats 0.4mm? you need a Henrob/dhc 2000

sticking to the mig I recommend an inverter mig, totaly variable ajustment

[takai]

Just welding the stock Cressida exhaust tip back onto the new system. Its 0.4mm steel (although it coudl be stainless, which might be why its arse to weld. I ended up securing it with 4 pop rivets.