just need some technical info on why you use argon mix versus straight co2 when doing body panel work. I thought the argon provided a cooler weld with less penetration which allows you to weld a very thin panel without burn through. straight co2 is hotter which gives a higher penetration but more potential for burn thru. is this correct?? a friend and I had a discussion on this and disagreed although he couldn't tell me the advantages of argon mix over straight co2. any info and experience would be appreciated. thANKS
I`ve never heard of using straight co2, for mig welding. And I believe argon makes a purer and hotter weld. I use pure argon for aluminum and stainless. and a 75/25 argon/co2 mix for mild steel. Try a real world test and let us know how it turns out.
The only straight Co2 application I've heard of is in windy places but I never understood how or why. I am curious how this works out for you. Keep us posted.
straight Co2 is lousy to weld almost anything with. Works better with thick than thin. Only time I ever used it was when the fab shop owner was too cheap to buy the mix, and too cheap to pay the piece work rate. Same guy refused adequate ventilation when welding galvanized too. He encouraged us to take many breaks. We fixed the cheap *******. First shift went out for a ten minute break and came back four days later to get our checks.
pure c02 penetrates more. the c02 displaces the oxygen which prevents contamination. The argon mix allows a lower voltage when mig welding. low voltage welding with c02 does not fully burn the weld or allow penetration. Ive not heard to use c02 for windy applications...thats normally when you would use flux wire or when you cant get a very clean surface.
C02 is not as temperamental to dirt and impurities in the metal as 75/25. The mix gas makes a cleaner weld as the 02 likes to spatter and send spit balls all over the place. having used 02 for the most part i think it burns hotter than the mixed. i use the 02 for most of my panel replacement and the mix on all the brackets and frame work.
Some guys use straight CO2 in the wind on-site in the field, because it is cheaper and you have to really crank up the gas delivery to maintain the shield in windy conditions. If you're going to use a **** load more gas, and you can get good penetration with the CO2, you're going to use it, because it's a lot cheaper than the mix. Welding inside, I'll not use anything but 80/20 or 75/25 mix (depending on what the airgas guy has in stock ) because I think it welds better on just about everything. Outdoors, we used to use flux core, but we found that if you pretty much triple the gas flow, you can use gas shield outside in just about any conditions (save for maybe gail force winds, or steady rain, of course). That makes a better weld than the flux core, and it's faster too ('cause you're not getting as much metal per inch of wire with the hollow core stuff). It uses a lot more gas though, so we use CO2 because it's a lot cheaper than the mix. I've never had to weld 20 ga in the field though. We pretty much never have to do anything but structural work outside (like 11ga or thicker).
Read this and you will understand. CO2 keeps welds, from being brittle. Gas metal arc welding <!-- /firstHeading --><!-- bodyContent --><!-- tagline -->From Wikipedia, the free encyclopedia <!-- /tagline --><!-- sub***le --> <!-- /sub***le --><!-- jumpto -->Jump to: navigation, search <!-- /jumpto --><!-- bodytext --> Gas metal arc welding Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode and a shielding gas are fed through a welding gun. A constant voltage, direct current power source is most commonly used with GMAW, but constant current systems, as well as alternating current, can be used. There are four primary methods of metal transfer in GMAW, called globular, short-circuiting, spray, and pulsed-spray, each of which has distinct properties and corresponding advantages and limitations. Originally developed for welding aluminum and other non-ferrous materials in the 1940s, GMAW was soon applied to steels because it allowed for lower welding time compared to other welding processes. The cost of inert gas limited its use in steels until several years later, when the use of semi-inert gases such as carbon dioxide became common. Further developments during the 1950s and 1960s gave the process more versatility and as a result, it became a highly used industrial process. Today, GMAW is the most common industrial welding process, preferred for its versatility, speed and the relative ease of adapting the process to robotic automation. The automobile industry in particular uses GMAW welding almost exclusively. Unlike welding processes that do not employ a shielding gas, such as shielded metal arc welding, it is rarely used outdoors or in other areas of air volatility. A related process, flux cored arc welding, often does not utilize a shielding gas, instead employing a hollow electrode wire that is filled with flux on the inside.
I used straight CO2 for all the welding in my muffler shop. I'm tight and I never had a problem with CO2. I started out using an argon CO2 blend but I could see no difference with the cheaper CO2. If you are building a space ship with critical tolerances then you might want to step up but for me the extra cost is wasted hotrod parts money.
I've used CO2 in my Miller 35S for 30 years with .035 wire running mostly on temp tap 3. I just looked at the chart inside the welder. interesting to me, i guess. E70S wire ----------.030 wire........030wire..........035 wire.............035wire ------------MIX ---------CO2---------- MIX------------ CO2 heat tap 1 ----------best--------- fair----------- fair------------ fair 2 ----------best--------- fair---------- good ------------fair 3---------- good --------good--------- good ------------good 4 ----------good --------good ---------good------------ best 5-----------fair ----------good--------- good -----------good 6---------- fair ----------good ---------good -----------good
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