Gas mix for mig welding??

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Good morning folks. Let me introduce myself before moving on with my question. My name is James, I'm from Ontario Canada, I'm 33 and haven't done a whole lot of welding in my life other then in school, I can't really remember much about the gas to use and settings. I own the Lincoln electric 140 mig pac, it gives me the option to use gas or go gasless, I'd prefer using gas because if my memory serves me right its easier and better. Now my question is what gas mix do I get? I have a project I'm working on now that ill need to do some welding, I'm building a bbq from a 55 gallon drum, the first thing ill be needing to weld is the grill, ill be getting expanded metal for that and some sort of angled steel for the edges as support, I talked to the steel shop looking for stainless for the grill and the guy said I'd be better off getting carbon steel? (No clue what that is haha) He said most ppl use that, its cheaper and just as good. Anyways I'm confused on the gas mix I'd need to weld that, tons of contradicting info on the net, when in school I only remember the one bottle of argon/co2 and welding whatever but what I've read says different mixes for different projects. Ill be buying myself a bottle to have on hand rather then rent so I don't want to buy it just for the little bit of welding I need to do on my bbq. I'm hoping there's an appropriate mix I can get that will allow me to do this project with ease and still be able to use the rest of the gas on other small jobs around the house, from auto work to fixing lawn mowers or even a kids bike. There has to be a common mix for this otherwise it would be cheaper to pay someone or just buy new parts haha. Any help on this would be great. Thank you for taking the time to read this and answer. CheersLincoln Electric MIG Pak 140 Wire Feed WelderSupport CASAA http://www.casaa.org/Donate_LKWE.html
Reply:James, you want 75%Argon-25% CO2, commonly called C25.  That mix is what you use for 99% of Mig welding.Last edited by cope; 06-20-2013 at 11:32 AM.
Reply:Originally Posted by copeJames, you want 75%Argon-25% CO2, commonly called C25.  That mix is what you use for 99% of Mig welding.
Reply:straight CO2 for most penetration. or stainless80/20 mix for less penetration and less splatter (depending on the size of the machine should be fine for up too 1/8" thick single pass, or 1/4" if you are welding on both sides)75/25  most common, little more splatter than 80/20, but a little more penetration.straight argon for Ali.for your purposes I'd go 80/20 for now (you may have to have that mix ordered in if your LWS doesn't stock it regularly). I'd stay away from automotive repairs until your a much more comfortable/knowledgable with welding. unless it's very minor body pannel repair. Also, Owning a bottle, doesn't mean you get the same bottle back, at least not in the states. It just means that you don't have to pay the rental fee. You take the spent bottle in, and they give you a different bottle which was already filled of the same size. in what ever mix you wanted.carbon steel is just regular steel and is what is commonly used for expanded metal grill surfaces. keep it seasoned just like you would a cast Iron skillet and you'll get many years of use out of it. Carbon steel = non stainless steel. there is High carbon and low carbon (mild steel) High carbon is very hard, used in knives and tools and such. mild steel, which is what the guy at your LWS was talking about is much easier to work with. and is also what is most common.Last edited by ThorsHammer; 06-20-2013 at 12:26 PM.There are no problems. There are only solutions. It's your duty to determine the right one.Hobart Handler 210Airco 225 Amp MSM Stinger
Reply:Originally Posted by ThorsHammerstraight CO2 for most penetration. or stainless80/20 mix for less penetration and less splatter (depending on the size of the machine should be fine for up too 1/8" thick single pass, or 1/4" if you are welding on both sides)75/25  most common, little more splatter than 80/20, but a little more penetration.straight argon for Ali.for your purposes I'd go 80/20 for now (you may have to have that mix ordered in if your LWS doesn't stock it regularly). I'd stay away from automotive repairs until your a much more comfortable/knowledgable with welding. unless it's very minor body pannel repair. Also, Owning a bottle, doesn't mean you get the same bottle back, at least not in the states. It just means that you don't have to pay the rental fee. You take the spent bottle in, and they give you a different bottle which was already filled of the same size. in what ever mix you wanted.carbon steel is just regular steel and is what is commonly used for expanded metal grill surfaces. keep it seasoned just like you would a cast Iron skillet and you'll get many years of use out of it. Carbon steel = non stainless steel. there is High carbon and low carbon (mild steel) High carbon is very hard, used in knives and tools and such. mild steel, which is what the guy at your LWS was talking about is much easier to work with. and is also what is most common.
Reply:So, if I understand correctly - I can use straight CO2 for steel (for good penetration) and also stainless welding?Thanks,RocketmanRay
Reply:Originally Posted by rocketmanraySo, if I understand correctly - I can use straight CO2 for steel (for good penetration) and also stainless welding?Thanks,RocketmanRay
Reply:Originally Posted by rocketmanraySo, if I understand correctly - I can use straight CO2 for steel (for good penetration) and also stainless welding?Thanks,RocketmanRay
Reply:Originally Posted by MinnesotaDaveI've used CO2 on steel and it works fine for me, my brother doesn't like it at all.  I can't say on stainless, I've not seen it done personally.James416 - I'd use 75/25 if it's the most common at your store.  If 80/20 is most common then use that.There is no need to order anything special to just do "around the house" projects on mild steel.Dave J.
Reply:JAmes416- Can you PM me. I have a topic/off-topic question for you. Thanks. Mine is Jlames.
Reply:I could be wrong on the CO2 for stainless, but that's what I remember. I believe Helium can be used as well.There are no problems. There are only solutions. It's your duty to determine the right one.Hobart Handler 210Airco 225 Amp MSM Stinger
Reply:Originally Posted by jlamesJAmes416- Can you PM me. I have a topic/off-topic question for you. Thanks. Mine is Jlames.
Reply:Originally Posted by ThorsHammerI could be wrong on the CO2 for stainless, but that's what I remember. I believe Helium can be used as well.
Reply:Originally Posted by Silicon-basedStraight CO2 no good for stainless MIG! There are some flux-core wires for stainless that use CO2 for shielding but for hard-wire MIG the results will not be good.You want argon with 2 to 5% CO2 or tri-mix (He/Ar/CO2) for best results with stainless steel.John
Reply:Originally Posted by James416With my starting post and the expanded metal (carbon) I'll be tacking an angle edge for strength, angled iron? Angled iron-expanded steel (carbon)? 75/25? I'm getting a few FT extra to practice, but am I good? I'm buying tomo after work. Cheers
Reply:Originally Posted by MinnesotaDaveYes, you are good with 75/25.  It's probably listed under your welder door and I know it's listed in your owners manual.No need to overthink basic mild steel mig welding.  Dave J.