Will straight argon or 75/25 work work on small stainless weld?

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Hi,I have welded a couple of projects in past with DC stick and proper rods, but now I want to do a very small non-structural repair, and think I used all of the rods. Not sure what grade stainless.Would mig with straight argon or 75/25 allow any reasonable results or complete garbage?(have large roll of stainless mig wire).  I am talking about a 1/4" area to build up, then grind smooth.
Reply:For best results, you will need a Tri-mix.  And it will have to be prepped & cleaned like you were going to TIG weld it.You can use regular wire, but you loose the corrosion resistance of the stainless.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:Thanks for the quick reply Mark!  But, if I don't have tri-mix, and don't want to get a bottle, for 1 - 2 seconds worth of welding, do you think either the straight argon, or 75argon/25Co2, or no gas, would at least allow the weld metal to "stick" to the parent metal.  I am not looking for pro results, and it is non structural.  Just need to build up a broken piece.
Reply:Thanks to you both. I forgot about his recommending mild wire, as I was thinking about the tri-mix part above.
Reply:I never tried 75/25, but you could try it or the Argon.  The Tri-mix is 2.5% CO2, 7.5% Argon & 90% helium in it, so I'm not sure how Argon or the 75/25 would work.  Maybe try it on some scrap?MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:Use 70s6 and paint the part so it doesn't rust that's your best bet......Stainless won't wet out with out that Helium  regular steel mig gas will work with steel wire for that small of a fix, just turn it up and let it rip......  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Stainless comes out real crappy with 75% 25% gas. Use TriMix and your good.
Reply:found a few 316 rods, so I will likley give them a try.Thanksfor all of the input!
Reply:Some use stainless flux cored wires  with C25  but I never try it so don't blame me if your weld look like bird poop... I warn you! Your on your own Kobelco and Avesta produce them and I think Lincoln use to got some in their line up but I'm not sure they're still available.Last edited by OldSkull; 12-16-2012 at 08:52 AM.Miller MM211Esab Mini Arc 161LTSEsab Handy Plasma 380Duck tapeTy- rapKool-aid
Reply:I used 75/25 with pretty good sucess. The co2 will make the arc hotter than pure argon and will spatter a bit but will work. Just needs a little more cleanup. I tried it after being told by a salesman at a welding supplier that pure argon is good for stainless and the trimix was a marketing scheme by the industry. Dont know for sure about the scheme theory but I do know that 75/25 works fine with a little adjustment.RG
Reply:"I tried it after being told by a salesman at a welding supplier that pure argon is good for stainless and the trimix was a marketing scheme by the industry"Sounds like somone needs a different supplier.
Reply:I used 82/18 mix and 316 stainless wire for some stainless job . I works but it looses some cor. resistance. Welds were nice. The best gas would be 98/2 or trimix.
Reply:I've used both tri-mix and straight argon when welding stainless. The only problem I've ever had with straight argon was when my tank was contaminated by the supplier. Is there a big price jump with tri-mix?Quality craftsmanship in the shop or in the field...
Reply:One issue with "tri mix" aka A-1025 is it is 90% helium and with supply issues with helium a)can you get any A-1025 and b)how much would it be.
Reply:I paid $260 for a 200 CF tank here.  That was $100 for an empty 200 CF tank, $160 for the new one & hydro on the old one.I just bought a 100 CF Argon tank last week for $240.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:Using argon co2 75 25 mix on stainless steel is good for single pass welds only if corrosion resistance is not prime importance.  If corrosion resistance is prime importance or is multipass weld use a trimix gas or use a 98 /2 argon oxygen for a spray transfer.