Any one mix their own welding gas?

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I have always had Argon around for stainless steel, titanium and aluminum welding and have always done my mild steel welding with flux core wire (using my 135amp Lincoln). Last year I got the chance to use a miller with C25 gas loaded with .025'' wire. It was pretty nice not having metal splattering every where. Also I have read that stainless steel is best welded with a 3% CO2 to argon mix and that using pure argon is not ideal. I have talked to a few people that run straight CO2 for mild steel wire, none could offer a better discription than "it works" and "its cheap". Wanting to try all this with my single welder and with out buying 4 gas bottles (pure Argon, C25, C3 for stainless, and straight CO2. I simply added a CO2 bottle and regulator then plumbed them together for use with my Argon. As we all know the C25 mix in a mig is good for clean metal, great for over head welding. Very little splatter. And the welds just look really nice. So far I have I mixed my own C25, (roughly 25% CO2, some where between 20% to 30% CO2) producing the same result as when I used store bought C25. I tested pure CO2 and found "it works", a marked improvement from flux core wire. Works well over light rust, little bit of zinc galvanization, or small amounts of paint/primer that didn't get removed. Still a little messy and poppy sounding. The main reason I tested pure CO2 is to see what happens in case I run out of argon. It would be great for sticking 2 peices of dirty steel together that you can't see and don't really care about. After testing straight my C25 home brew I realized my argon bottle was running low. I figured I would try higher C mixes since CO2 by volume costs a tiny fraction of the same volume of argon. So I tried a 50/50 mix of CO2 and argon and it seemed to produce welds as good as C25, tho the welding process its self was messier.  Slightly surprized by the result I figured I would try and add more CO2 to find the CO2/Argon limit for what I want out of my welder. Turns out 5 parts C02 to 2 parts Argon seems to be about the limit of what I am looking for using .035'' solid wire. The welding process is poppy and does spatter almost as much as pure CO2 but the welds look very good. If I put down a bead using C25 next to a bead ran using C70 you would be surprized how little difference there is. Biggest difference is not the bead its self but the spatter around it.But you would know the difference if you were to over head weld with hi CO2 mixes, next time I have to over head weld I will be going at it with a 75% or higher Argon mix.I finished off the .035'' solid wire I started with.I respooled the welder with .025'' wire and tried it out welding some 1/4 inch steel to some 3/16'' steel and it worked great with my little 135 amp welder. Tried using pure Argon again, that only lasted for a few inches of bead, it sucks, the weld bunches up and penetrates almost as if the polarity is backwards (but with out the spatter) so I switched back to my 70% to 80% CO2 mix, there is so little difference between the 2 mixes I don't know why people spend so much money on C25. I tested my setup mixing my own 3% CO2/Ar for stainless welding.I run about 12l/min of argon and take my CO2 regulator that starts at 4l/min and open it up just enough to make the metering ball bounce on its rubber base.I get much better weld penatration than when I was using pure argon.I ran out of solid mild steel wire Saturday evening (labor day weekend) so I put in a spool of flux core, switched polarity and figured I would try something little different. Since I had plenty of CO2 (so I thought) I tried running 4 to 5l/min of CO2 over the flux core. I figured best way would be to do a CO2 off-on-off test and figured it would be no different one way or the other and I would just end up turning the gas off and leaving it off. First test was to remind my self what a messy burn and fire hazard straight flux core wire was like.Then switched on the CO2, right away I noticed the flux core with a little bit of CO2 does not spatter as much and lays down nicer welds. I turned off the gas and came back later and started welding again, right away I realized I like it better with gas on.I finely ran out of CO2 on September first (the next day), I have been using that single 15lb bottle of CO2 since april, welded tons of stuff with it. My single 15lb bottle of CO2 lasted through 2 or 3 short bottles of argon (40 cubic foot cylinders), burned up 4 or 5 pounds of solid core wire running a C50 to C70 mix most of the time, plus I burned up a pound of flux core running a little bit of CO2 coverage. Also did a little pure CO2 solid wire welding, maybe 15 or 20 minutes total. I tried welding with pure argon again and was reminded how much it sucks (with mig at least). On a side note it rained that night, all the welds developed a little rust coating except for the 2 inches I laid down with a pure argon shield before giving up on it. If you were so inclined you could rig a welder using 50/50 to a C70 mix and run a tall bottle of pure argon next to a 15 or 20 lb bottle of CO2 and run them for ever compaired to running and always running out of C25. Or for a small scale welder a short bottle of argon next to a 20oz paint ball CO2 bottle could be a good pair. (maybe I should have done that) I would like to add a new dimention to my on site gas mix welding with the addition of Helium, but my gas supplier never has any 40cu.ft bottles. Helium could take the place of adding a little CO2 for its "wetting" ability when welding stainless steel and it would be really nice to have some of that wetting ability when welding titanium. Has any one else tried doing this? This is a condensed version of what I posted here:http://www.thirdgen.org/techboard/fa...c-mig-gas.htmlLast edited by mad welder 4; 09-04-2013 at 04:43 PM.
Reply:I have often thought of doing this, using a y fitting, separate flowmeters to give me a choice of pure argon, argon/CO2 or pure CO2 as required.  The info I have found says that mixing is inconsistent and would not meet code requirements were they required.  My info also says that doing this without a specialty mixing chamber is not going to work properly and these mixing chambers, which I believe are made by Smith (Miller) are very expensive.  All this in order to save renting a C25 bottle in addition to an Argon and CO2 bottle.So far I haven't tried it, if anyone has this figured out  please post your methods.  Mad Welder 4 has got a good start on this.  I wish there was a piece of equipment we could buy or build which would make this possible and give accurate mixtures as required."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:Doesn't that Marcella (sp) guy that makes aluminum intake manifold mix his own gas? I think I've heard that some where before. If so, what does he use?I too have had this idea, but have never had a means to actually do it. I think the twin flow regulators us the way to do it.The other alternative is this:http://m.grainger.com/mobile/details...lap551?R=2CZP3Sent from my SGH-T989 using Tapatalk 2
Reply:What you need is a gas mixer..Better be sitting when you read the price....Seems about right..http://www.ebay.com/itm/350451132179?hlp=false&var=I have one for tig but I am not sure if it would work with a mig BUT I really don't see why not..Never tried it....zap!Last edited by zapster; 09-05-2013 at 05:04 AM.I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I use Smith gas mixers on a daily basis................they work well.  0-100% CO2.....0-100% AR.6 Miller Big Blue 600 Air Paks2 Miller 400D6 Lincoln LN-25's4 Miller Xtreme 12VS2 Miller Dimension 812 4 Climax BW-3000Z bore welders Hypertherm 65 and 85Bug-O Track BugPair of Welpers
Reply:Originally Posted by ExpatWelderI use Smith gas mixers on a daily basis................they work well.  0-100% CO2.....0-100% AR.
Reply:Jody and weldingtipsandtricks mixes with a y-adaptor.In this video he shows it right at the beginning (the video isn't actually about it).http://www.weldingtipsandtricks.com/...ium-argon.htmlDave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by dcoffmanjrAt $3k that thing better work fantastically, magically, phenomenally, or something better than "well"I would love to see a flow diagram of the mixer to get a better understanding of how exactly the work, before I could see spending that kind of money. Sent from my SGH-T989 using Tapatalk 2
Reply:Originally Posted by ExpatWelderI use Smith gas mixers on a daily basis................they work well.  0-100% CO2.....0-100% AR.
Reply:i mix my own gas on a daily basis be it at work or at home .... Use Smith Mixers the benefit is that i can make any ratio for the application that i am working on ... with out the need for tons of bottles of premixed ratios ... plus its just a turn of the dial and bamm i have the ratio i need we do have a old simet http://weldingtradesman.com/download...10&mode=viewin in circulation with the Smiths mixers at work ... work along the same principalMiller Xmt 350Lincoln Ln-25Ahp 200xSmith Gas Mixer AR/HTig is my Kung FuThrowing down dimes and weaving aboutInstagram http://instagram.com/[email protected]
Reply:Originally Posted by 96708Why do you use this? Just to save money on gas? Is there other benefits?
Reply:I don't see why a length of small diameter line wouldn't mix the 2 gasses.Flowing 15L/min through a small line like what most of us use would cause the gas to flow through the line in what engineers would call fully turbulent state. If still in doubt about the gas not fully mixing then run it through a 90 degree elbow.Flow meter with something finer than standard flow meter graduations marked in 5L per 3/8'' or so would help a lot when trying for the 2.5%CO2 Argon mix migers use for stainless. Seriously who needs 60 cubic feet per hr of argon?
Reply:This has been covered many times before. The main thing the correct mixers have is a balance regulator to keep the pressures of the input gases at exactly the same pressure. That's the hard component to get. The rest is not difficult but does require knowing a few details.   This thread covers a lot and has a link to my mixing setup in it as well. http://weldingweb.com/vbb/showthread.php...MIG&highlight=Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Originally Posted by zapsterWhat you need is a gas mixer..I have one for tig but I am not sure if it would work with a mig BUT I really don't see why not..Never tried it.
Reply:I have a smith mixer and I use it to mix pure argon against C25.  I cannot cheaply get small bottles of C10 for pulse welding.I picked up a Smith mixer (O2 / CO2) for $500 off Ebay.  Added two regulators - which feed the Smith at 50psi.  Inside the Smith is a special pressure balancing regulator that insures that both gases feed at exactly the same pressure (I measure it to about .02 psi difference...)  Then it goes to a mixer, then it goes to a flow control.   I run the flow control wide open and feed it into the 2nd stage of a flow meter and control the flow there.To verify the mix, I use a automotive 5 gas analyzer.  It registers the Argon as oxygen and registers the CO2 as CO2.  It can only read up to 20% CO2 (which is more than I need).   A sharpie mark on the front of the smith mixer indicates 2% 8%, 10% and 20% CO2.  I double check every now and then.Here's that bad news.   I spent about $600 (estimated value of parts) to save myself $30 'special order' fees per bottle.  I run through maybe 4 bottles a year....  I've got a ways to go....    And to top it off, the Multimatic welds so smooth, I prefer that over pulling out the 350P for all but the biggest welds.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Con fuseI believe you are doing it right with your setup, thanks for the details.I believe you are right about the cost also. "The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:I picked up a Helium tank today at the scrap yard, for maybe $4, hydrostatic test is good but the valve stem handle was broken, had a little surface rust and was a little beat up.Dropped it off at the welding gas shop just before closing and they said they would take a look at it in the next day or 2 and see if its viable and will install a new helium valve stem as long as everything looks good.Then I can make my own try mix, I don't think I need any where near 90% helium to get the benefit of helium.
Reply:I use a lot of Helium, and the only problem your going to have is making sure the gas is clean along with your cylinder......dirty helium makes for crappy looking welds...and you usually get what you pay for with Helium deals.....  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:I went and checked on my helium bottle today, they had the valve off and had tape over the hole, so they are at least smart enough to do that.And they had put the valve on order.Should I go down there with some acetone and rinse out the inside of the bottle?I am pretty sure the gas dealer is going to send the cylinder off to Amarillo. I was just going to get industrial/welding helium.
Reply:I wouldn't. There should be no reason to introduce anything inside that cylinder. If the inside has issues, it's probably due to rust and they could bead blast or tumble the cylinder if needed. The only ones my hydro shop cleaned was O2 cylinders since contaminants and 100% O2 don't play well together. They certainly would never use acetone for that though.I'm a bit surprised they didn't have a CGA 580 valve in stock. My guess is that they want to use one with a dip tube for some reason vs a standard valve. Honestly never saw any difference in mixing between the two with basic gases..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I took my bottle to a fire supply company. Almost all the valve head swapping they do is CO2 or Oxygen related.They do all the hydrostatic tests for a very large area, to include the welding gas company and medical oxygen supplier.If I went to the welding gas company they would just try to sell or rent me a bottle, which for helium is only 300cu.ft cylinders at the moment.I should add they think my bottle started out as an oxygen bottle, so it should be real clean in there.
Reply:Ok that makes a bit more sense. Most of my hydros I get done at a regular hydro shop that does all sorts of cylinders. Occasionally when I need one done quick I take it over to Jersey and use a place that mostly does fire extinguishers..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Pics of the rig:http://weldingweb.com/vbb/showthread.php...11#post3056911
Reply:I got my Helium bottle back.Little 40cu.ft bottle hold $75 worth of Helium.I installed the bottle to my welding cart, put a regulator on it but have not plumbed it into my gas line yet.Lately I have been using 10L/min of CO2 and 6-7L/min of argon on regular steel. My latest side project has been to weld up a hedgehog made from pointy bits of scrap metal, when ever I do that I turn off the Argon and just use straight CO2 at 10L/min.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder