CO2 VS Argon/CO2 mix while ferrous steel

[performance]

CO2 is a metal active gas. It is not inert. It causes more spatter by its nature, and it is like going backwards in the smoothness of the arc, although inductance can tame it somewhat. More smoke, and usually a dark, dull weld appearance from the oxidation that takes place. I've used, it and won't use it unless 100% necessary. It does penetrate but the spatter alone increases clean up time and makes spatter removal much more difficult as the BB's seem to freeze much more solidly to the metal. I figured the difference in clean up time, and given the way that I charge my customers (not to mention the hassle) it pays to run a mix.

[Johnson]

The WPS required vertical down...also on thinner metals you need to use vertical down since you are moving into a cooler area of the joint instead hotter. This keeps you from blowing through. Vertical down is widley used with GTAW, Brazing, SMAW, and FCAW for 1/8 sheet ans smaller. Yes for thicker metals you alwasy move up, but I took the test on 14awg. Forgot to say, if you use a flux core wire made for use WITH 100% CO2 shielding you will get some very nice results on 1/8" or thicker. The welds look like a spray transfer apperance. Lots of filler, and very low in discontinuities. I'll post some pics after class.

[Johnson]

Oh and yes gassless FCAW leaves a grayer weld, beacause of the lack of shielding and cool rate. But used with co2 and a flux wire made for co2 you get a VERY shiney wonderful weld.

[Johnson]

What the hell is spray transfer?

Spray x-fer only happens when you run a mix of 80% argon and up. You need at least 24 volts for your machine or more. Also you must use a solid core or metal core wire. Spary x-fer runs hotter and is not intender for all positions because of the bigger weld pool. It has a high deposit rate and is great for thicker metals. You cannot run 100% argon because of instable arc, it must be mixed with 2-20% CO2. Because of the high heat input into the metal Short circuit is mainly used for thinner metals. It creates less distortion in panels and things. Pulsed spray on the other hand can be used in most positions, with the right machine settings. The noise is differnt from short circuit. Instead of a zzzzzzzzttt. Buzzing fry sound, it just makes a hiss like a mad cat.

Short circuit is what most people use when they use there "mig" (GMAW) in their garage.

Globular tranfer is almost never used and when it IS most of the time it is being used out of error. People will have a 75-25% mix of argon co2 and "think" they are using spray transfer. The amout of current and voltage required to use spary transfer with that low of argon mix would be HUGE. Spray transfer is mainly used in more commercial settings. Lots of deposit and good looking welds

A great alternative to spray transfer is a flux core wire that uses CO2 to also shield it. The welds have a high depost rate, look great, and the gas is cheaper. You can also weld in all positions. Only draw back is the more cost in wire, and the flux has to be cleaned off (it almost falls off), not like SMAW. Hope that helped

[JimMinKent]

Good Morning Johnson,

Would you mind giving us some brand names / product names that you've had good results with, (for dual-shield use with pure CO2), that will save a lot of experimentation, Thanks.

Jim

[Johnson]

Sure I'll look tomorrow at class. I know its a Hobart .045. 70, 000 tensil. I'll get the flux type/ deoxidizer info then. I'll double check too about using it in overhead.......till then.

[Johnson]

Ok it's Hobart Excel arc 71 .045 on a 44 lbs spool. I'll grab some welds monday and take some photos. I'm looking forward to messing with spray transfer in a few weeks. Take care

[JimMinKent]

Thanks for the info When you take the pictures, can you show one before you clean it too? Thanks.

Jim

[Johnson]

I'll try and make a video of it...the flux FALLS off when you dip it in water or just touch it with anything. It's nothing like SMAW, you can tap on it with a pencil it and 95% of it just falls off. I'll see what I can do Monday for a video....

[Johnson]

Thanks for the info When you take the pictures, can you show one before you clean it too? Thanks.

Jim

Here's a few videos I just dug up on the "tube" till then. Fluxcore is very widely used in industial settings, like ship building, oil rigs and so on. Most people don't realize that it is one of the most used forms of wire welding. Flux core gets a bad rap from people that don't understand how it is used.

Here's one from Lincoln....

http://www.youtube.com/watch?v=C06aWgJByG0

And esnob

http://www.youtube.com/watch?v=_9bWgMRf9KA

Watch how clean it is and how the flux just falls off....lots of heat though and mostly used on thicker metal....

[Johnson]

Ok no chance to get a video but here's a pic of a 2F 2 pass weave.

[Mr120]

Great info everyone. So what are all of the hobbyists out there doing? Having a tank of 100% argon for aluminum AND a tank of CO2 to save money for ferrous? I'm going to have to do some math to see how much it might save me. I'm cheap so post weld cleanup doesn't bother me. I will either leave the splatter or will put some elbow grease in.

[youngnstudly]

Ok no chance to get a video but here's a pic of a 2F 2 pass weave.

It's been quite a while since I've seen a fillet block! It always seems like you weld block after block up in welding classes and it's never ending, but that's certainly the best time to try new things and learn as much as you can without anyone "breathing down your neck!" Nice welds by the way.

Have you done any dual shield welding in your class yet? I always loved playing with all the different welders and processes in school since you don't have access to all that equipment at home. I'd love to go back to college and brush up on my skills and knowledge one day (probably never happen though).

[Johnson]

Yeah, sorry that weave was flux core I love school! I'm glad I found an instuctor, school and trade that I enjoy doing...it really helps. I agree I have learned so much since I "thought" I knew a lot. The more you learn the more you understand you have way more to learn. I just started pulsed spray today and it's a whole other animal.....wierd, but awesome at the same time. I'm also glad I found out about these welders...I started learning GTAW by myself with my 185 Micro. If Everlast priced these units higher I honestly don't think I would have falling in love with TIG and went back to school.