View Full Version : Which welding gas


kht428
01-08-2006, 09:24 PM
Alright, I've got a 220v mig welder and was wondering if I could use straight CO2 . Alot of the mig spools I've seen have Argon/CO2 or CO2 only listed on them. What are the pros or cons. The reason I'm wondering is I've got a 10lb and a 20lb bottle of CO2 both full so if I don't need to get another cylinder that'd be great.

If I should get Argon/CO2 mix what the hell's the difference in the mixes. Is more argon better or just stick 75/25?
Thanks

shovelhead
01-08-2006, 09:32 PM
straight co2 gives more heat/penetration.c-25 cleaner weld less heat,and works fairly well on stainless steel without springing for tri-mix. regards shovelhead

waltman
01-09-2006, 12:19 AM
I would think as long as you didn't get porosity that you'd be OK, but to be sure you can phone a welding supply store, they will be able to tell you for sure.

MyFullSize
01-09-2006, 12:48 AM
We used C02 at the shop, I was very happy with it, great penetration, but we also ran dual shield.

Most rigs come with a regulator for mix. If you want to run straight, you will need, IIRC, a new regulator. The gas is a lot cheaper too. Check your local weld shop for setup and info.

Good luck, and Im glad you got a 220 unit, should do good for you!

Andrew

kht428
01-09-2006, 12:52 AM
I would think as long as you didn't get porosity that you'd be OK, but to be sure you can phone a welding supply store, they will be able to tell you for sure.
Went to my local Airgas right around the corner. They were real busy (1 guy on the counter) and he started talkin about three gas, four gas, and different argon %s but he didn't have the time to explain nor I the time to wait. I've read that the multi gas mixes are not needed and a waste of money. And I'm only doing basic welding nothing fancy.
Guess I'll try the CO2 and turn down the heat setting and see how it works. Thanks

f-4x4
01-09-2006, 12:59 AM
is it the same c02 thats in a paint ball tank

kht428
01-09-2006, 01:37 AM
is it the same c02 thats in a paint ball tank
It's the same CO2 that's in CO2 whether it's in a 20lb cylinder or 9oz cylinder.

Bronco Rob
01-09-2006, 02:14 AM
straight co2 gives more heat/penetration.c-25 cleaner weld less heat,and works fairly well on stainless steel without springing for tri-mix. regards shovelhead


He just answered your question. Your going to need to adjust your settings for straight CO2. And your going to have to adjust it back if you ever go back to CO2/Argon mix.

You'll be fine to use up those two cylinders, but for the backyard welder a CO2/Argon mix may be better.

SquattyD
01-09-2006, 02:24 AM
straight co2 gives more heat/penetration.c-25 cleaner weld less heat,and works fairly well on stainless steel without springing for tri-mix. regards shovelhead

x3.

co2 is hotter, but dirtier, more slag. c25 is a bit cooler, but a bit cleaner.

equin
01-09-2006, 02:31 AM
When I took a MIG welding class at the local community college in Dallas, the class shop used straight CO2 for all its MIG welders due to budget limitations. The instructor explained that an Argon/CO2 75/25 mix produces a cleaner looking weld with less splatter (the little dots that get sprayed near the weld area), but that using straight CO2 is still fine for welding mild steel.

kht428
01-09-2006, 03:55 PM
NICE! Thanks guys! Like I said I'll go ahead and use what I got when I can afford to buy/rent another cylinder I'll get the 75/25. :thumbup

If anyone else wants to chime if please feel free just please keep it simple. Between the counter guy and what I've found online there's way more technical mumbo jumbo then I thought could exist for explaining welding gases.:doh0715:
Thanks again

kht428
01-10-2006, 12:28 AM
Form the fabricator.com
http://www.thefabricator.com/Articles/Photos/653/fig1.jpg

RLKBOB
04-17-2006, 12:16 AM
Wondering if you've welded with that straight CO2 yet? I've been taking a welding class at the local CC since Jan and I knew that CO2 will give better penetration but more spatter. I'm just wondering if you've used it yet from experience is there a lot of spatter or not too bad? Any pics would be helpful. I'm just wondering because like I said our instructor tells us excessive spatter but what exactly is excessive? If it's not that bad then I might use straight CO2 when I get a new welder.

Dave's Bronc 90
04-17-2006, 12:55 AM
I never realized that changing the shield gas would have an effect on penetration. I've got a 20 lb. CO2 tank that I used to use for filling paint ball cylinders, I'll have to try that instead of the Ar/CO2 mix that I'm using right now. Frankly, cheaper sounds good to me. I can't imagine that the splatter is that bad, especially since I'm really more used to the splater from stick instead of MIG. Is it true that I need a different regulator for CO2? Buying another regulator might offset any savings from switching gasses.

MyFullSize
04-17-2006, 10:21 AM
My vote is still with straight CO2, and I dont know where the chart comes off with "less attractive beads", with experience you can run a bead that is a work of art! :thumbup

Still, like I suggested, check your weld shop, IIRC you need a regulator for straight CO2, the one that came with the rig is for mix... so check it out, I still have my buzz box so Ive not had to make that call yet (IE: I dont have first hand info as of now).

HTH,
Andrew

RLKBOB
04-18-2006, 07:09 PM
My vote is still with straight CO2, and I dont know where the chart comes off with "less attractive beads", with experience you can run a bead that is a work of art! :thumbup

Still, like I suggested, check your weld shop, IIRC you need a regulator for straight CO2, the one that came with the rig is for mix... so check it out, I still have my buzz box so Ive not had to make that call yet (IE: I dont have first hand info as of now).
HTH,
Andrew


Which is it? you don't know for sure from experience or you do? The big question isn't how you can make the bead look but how much spatter, straight CO2 is supposed to cause excessive spatter.

MyFullSize
04-18-2006, 10:38 PM
Which is it? you don't know for sure from experience or you do? The big question isn't how you can make the bead look but how much spatter, straight CO2 is supposed to cause excessive spatter.

1) About the regulator, I dont know for sure if you need a new regulator for straight CO2.

2) Ive welded 220V 150A MIG solid wire with both mix and CO2. True, mix yields less spatter, but CO2... really... there isnt a whole lot there either. Its just that mix is less. Not that mix is NONE, or that straight CO2 is aweful.

At any rate, keep the chisel edge of your welding (chipping) hammer sharp, and 99% of the spatter balls will knock off with one swipe.

Thus... whats all the commotion about? ;)

Good luck!
Andrew

RLKBOB
04-18-2006, 11:34 PM
That's exactly what I was wondering.
Since I have to get all new everything after the fire maybe I'll give straight CO2 a try. Most of the stuff I'll be welding on will be 1/4" for Bronco mods.

Sam Burton
05-10-2006, 07:07 PM
just thought I would throw in my two cents.
i bought a welder, just a little 110 volt Lincoln and it uses co2 and the welds look just fine, no more splatter than my brothers which runs the mix.
of course i'm not much of a welder and it is just for around the shop, but the welds look lot a hell of alot better than with my old flux core piece of junk.