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suggested MIG gas

Discussion in 'The Hokey Ass Message Board' started by recondotexas, Sep 11, 2012.

  1. recondotexas
    Joined: Oct 29, 2009
    Posts: 21

    from Austin, TX

    Hey folks,

    Could someone give some suggestions on the best gas mix for MIG? Work will be on nothing thicker than 1/8" tube as well as basic sheet metal patching. I've read a 75/25 argon/co2 is a good mix. And yeah I am obviously new to the welding world as this may be an obvious thing to most. Thanks in advance.
  2. I use 75/25 works great. I think it's 75 Co2 25 argon
  3. If I was just going to weld mild steel I would just use CO2 the argon mix is primarily for welding things like stainless and titanium. You can certainly weld steel with it but it is a little more pricey.
  4. recondotexas
    Joined: Oct 29, 2009
    Posts: 21

    from Austin, TX

    I'll just be using mild steel and aluminum. So straight CO2 should be ok? I am assuming a small rental bottle of that can't be very expensive. What do you guys pay for refills?

  5. red70racer
    Joined: Apr 20, 2012
    Posts: 2


    I sell welding gas for a living.
    The mix you want is 75AR/25CO-2
    It is the most user friendly for a variety of thickness
    Straight CO-2 works on mild steel, however the arc characteristic is very harsh, leaves spatter and is difficult to use on anything less than a 1/4" with that said, there will be someone on here that will say they are using CO-2 shielding gas successfully on sheet metal, it can be done it is just not ideal.
    You can use 75/25 to weld stainless as long as it is in a non corrosive or food grade, those require a helium tri-mix gas
    Straight argon only for aluminum or 90% of all tig welding
    I hope this helps
    Jeff Palazzolo
    Pacific, (St. Louis) Mo
  6. GMM
    Joined: Aug 9, 2012
    Posts: 53

    from Buhl, ID

    Co2 we use primarly, we change it up for welding stainless. Then we use tri-gas mix, 90% helium / 7.5% argon / 2.5% co2. If you have any other question, make friends with a good welding supply house. Anytime I`m not sure and neither are my employee`s we call the shop. They will lead you in the right direction.
  7. johnnydidd
    Joined: Aug 25, 2012
    Posts: 4


    I use 75% argon /25% co2, does a bueatiful job, straight co2 will give you more splatter which will take more grinding to clean up, co2 will penatrate more also which you dont want for sheet metal. Buy the cylinder if you rent you will pay for it in 3 years.
  8. I worked comercially with MIG and while you are no doubt a good salesman you are not much of a welder. We used CO2 with sheet metal as thin as 18 gauge, no problems. Day in and day out.

    We used argon mix for stainless and titanium but anything in any of the shops that I worked in steel was CO2 only.

    Great first post by the way.

    Neither is real pricey by the way, last I filled my little bottles there was only about 2 or 3 dollars difference.
  9. RamJet1
    Joined: Apr 9, 2012
    Posts: 343


    I'm no expert, but I use the 75-25. Works well.
  10. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    from florida

    The first time around is where you take the price hit, the bottle itself gets pricey. Some places rent them but I think it is best to just buy it to start with then you own it and no more monthly rental fees. I forget the price, and it depends on the size. We use what they call down here a number 4 bottle, the biggest one, and a refill on that size is in the $50 range. We usually swap ours out at Northern Tool, and we buy the 75/25 mix.

  11. 75 argon / 25 CO2 will work just fine for what you want to do , that's what i use with my mig.
  12. stubbsrodandcustom
    Joined: Dec 28, 2010
    Posts: 1,427

    from Spring tx

    Find your nearest welders supply... we did the northern tool crap and got our fair share of empty bottles and had to go back and forth... buy you a bottle... normally a #3 size... bout 200 bucks... To go to a welder supply they normally will swap your bottle out each time for about 25 to 30 bucks per fill...

    75/25 is best for doing normal car welding... straight co2 for alum etc...
  13. chopper526
    Joined: Sep 12, 2010
    Posts: 252

    from Phila., PA

    75/25 mix is what I used to do my whole car. I am definitely no welder but that's what Lincoln recommended for what I was doing.
    What I did do was change the gauge of the wire depending on the thickness of the metal I was welding. But, like I said, I am no welder and am learning as I go.
  14. mrconcdid
    Joined: Aug 31, 2010
    Posts: 1,157

    from Florida


  15. recondotexas
    Joined: Oct 29, 2009
    Posts: 21

    from Austin, TX

    So there's two trains of it. Does the skill level of the welder make a difference? I imagine porknbeaner is probably at the pro level and maybe using a setup that requires the skill level to control the gas mix/bead/speed, ect is good for him. Me? Hell i'll go through a pile of scrap practicing so if either gas is more forgiving (if that's possible) then that's what I need. Oh and i'll take the advice and just buy a bottle.
  16. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    from florida

    No, it is just like most things automotive, everyone has a different opinion and preferences. Doesn't necessarily mean one person is wrong and one is right, we just tend to like what we have used sucessfully in the past. Kinda like the old Ford vs Chevy thing. :)

  17. you are over-thinking it , get the 75/25
  18. recondotexas
    Joined: Oct 29, 2009
    Posts: 21

    from Austin, TX

    75/25. Thanks folks.
  19. Car
    Joined: Nov 22, 2011
    Posts: 83

    from the desert


  20. You will notice that it seems like the weld is hotter with the CO2 I don't know that your skill set is going to really matter, welding in 90% practice and 10% technical. We used to start fellas that had little to no experience out in one shop I worked in (sweat house actually) using CO2 on heavier stock like 10 gauge (approx. 1/8") sheet metal or 1/8-3/16" angle. Then as they got to where they could handle the job if they did well we began to train them on close tolerance stuff with more exotic metals and Argon mix.

    Either will work for you, you may never use CO2 at all and be just as happy as a duck in mud. I don;t see going to the exppense of the argon mix for mild steel, but it will work just fine. It just isn't a necessary evil in my opinion.
  21. wheelkid
    Joined: May 25, 2006
    Posts: 1,206

    Alliance Vendor
    from Fresno, CA

    Anyone else ever use 98/2 with CO2/oxygen? I've only used it when spray welding. It works well, very hot.
  22. OshkoshRob
    Joined: Jun 16, 2008
    Posts: 388

    from Oshkosh

    75/25, about $36 for medium size tank exchange.
  23. roddinron
    Joined: May 24, 2006
    Posts: 2,677


    I'm with porknbeaner on this. I used to use the mix, and was spending a lot of money on gas, as well as time wasted to go get it. I mentioned it at my supplier and he recommended straight CO2. He said filling a tank wasn't much cheaper, but it would last a lot longer since CO2 is a heavier gas. He was right, I make way less trips for gas now, and really can't see any change in my welds. Works for me, "your results may vary".
  24. Did you ever ask yourself why there are so many different types of welding gas ?.
    That's because there are that many different types of welding.
    Sort of why there are different pots and pans, or hammers and dollies, or carb jets.
  25. I change bottles between my TIG and MIG so I just started using Argon rather than keeping bottles of Argon and 75/25 in the shop. I used to use straight CO2 with my MIG but I didn't like the spatter that I always got using it. The 75/25 is better but I have found the argon works best for me and the price isn't that much more the 75/25 at the welding supply shop I use.
  26. I'm with beaner on this.
  27. black 62
    Joined: Jul 12, 2012
    Posts: 1,895

    black 62
    from arkansas

    follow the manufacturors recomendations--they want you to be a successful, happy repeat customer---anectdotal evidence and opinions are often embellished--that said the argon mix is more novice friendly---straight co 2 for chassis work---check the Miller web site--i supervised mig, tig, arc, and brazing operations for years and always trusted my welders and manufacturors reps--myself, i am a total amature and follow Miller recomendations on heat , wire size and type, and gas
  28. rustang
    Joined: Sep 10, 2009
    Posts: 710


    I prefer 75/25 for almost all my mig work, sheet metal up to about 3/16. anything heavier, or stuctural i use the arc welder with 7018 rods in DC mode....

    For thicker material and only using the wire feed I've used the flux core wire, not pretty, but effective...never on sheet metal though.
  29. Core wire is a good option over rod if you don't own a stick welder, or have large productions runs of structural components that require a specific rod type with an Xray quality weld. Most of us are not going into the whole structural welding thing, but it is a good alternative to rod.
  30. I use small tanks about 30" tall 6/8 dia 75/25 mix . works great for sheet metal frame ect. Last week I paid $ 98. at air liqude that must be a small tank for $36.

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