Argon/CO2 do percent matter?

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For MIG i use 82 Argon / 18 CO2 mix since long time.A lot of people use C25, some C15 which is believed by some as more universal. What do you guys think? Would i see a difference if i change from my mix to C25 or C15?Tom
Reply:depends on if you are short arcing or spraying or BothMiller Xmt 350Lincoln Ln-25Ahp 200xSmith Gas Mixer AR/HTig is my Kung FuThrowing down dimes and weaving aboutInstagram http://instagram.com/[email protected]
Reply:Sorry, forgot. Mostly body work and thin steel up to 1/4. Speed is no concern. Quality is. So short arc it is. Need to be able to do out of position welds as well.I know i can do spray with my mix too, maybe not ideal but its working. Normally i dont need spray.My machine is doing pulse/twin pulse as well, not sure if this has any influence to the gas needs. Didnt play with this modes till now, got the machine some months ago and had no time for this.Last edited by tomelgato; 12-02-2012 at 01:45 PM.
Reply:Refering to this chart im loosing the spray capability if i go to C25:http://files.aws.org/wj/2006/02/wj20...j200602-46.pdfBut as said before this would be no great loss for me if it has any advantage for my normal work.Pulse is another thing. This i like to try. But also i like to stick with not so many bottles (for the few times i do SS or Alu)So:1x A/CO2 (75/25, 82/18, 85/15) mix for mild/carbon steel (optionally spray option). Focus on under 1/8 steel and gauge.1x A/CO2 (97.5/2.5) or A/O2 (98/2) mix for short arc SS and  for pulsed SS and pulsed mild/carbon steel (matt posted neat results on SS with A/CO2 on similar machine & pulse: http://weldingweb.com/vbb/showthread.php?t=30845&page=14)1x A (100) for TIGLast edited by tomelgato; 12-02-2012 at 02:33 PM.Lorch Saprom S3, Lorch V24, Hypertherm 65
Reply:The three tanks you mention in your last post are very good choices; for the first tank, stay with the 82/18. It will give you better results than the 75/25 on thin sheet.Spray might be theoretically possible with 15 - 18% CO2 but is much better with 10% or less.  I usually use 3 or 5% CO2 because they work well with either stainless or mild steel.Ar/O2 mixes make a more fluid puddle but are not so good for vertical or overhead welds.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:97-3 will work for anything, stainless or carbon, spray or short circuit.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:Expat, 97-3 you mean AR/CO2 too?Whats the disadvantage compared to 82/18?Sorry if i ask stupid, i did read lots of technical papers the last days, but they all differ a little bit.Last edited by tomelgato; 12-03-2012 at 10:24 PM.Lorch Saprom S3, Lorch V24, Hypertherm 65
Reply:Funny, yesterday i did take a look at my bottle to find out they changed the mix on the last delivery. Did weld some 1/8 and thicker material without probs during the last months but no thin sheets. But on 2mm material i had some burn trough issues. Question ... is it getting hotter regarding the O2?The actual mix is: AR 82, 14 CO2, 4 O2Unfortunately i have no bottle with the old 82/18 mix on hand, so i cannot compare.Lorch Saprom S3, Lorch V24, Hypertherm 65
Reply:Yes, the oxygen makes the arc hotter and 4% is quite a lot. That mix is not much good for anything except steel in flat and horizontal position.See if you can get your old 82/18 mix back, and add a tank of the 97.5/2.5 if possible.If you want to use the pulse modes of your machine, 5 to 10% CO2 is best for mild steel. A bit cold for short-arc, though.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Thanks. Will talk to the vendor. Somehow i never thought about the gas, used always the same till i did start reading Lorch Saprom S3, Lorch V24, Hypertherm 65
Reply:So, got my old 82/18 mix again, much better now. I got the mix with oxy same time when i purchased a new machine and wondered why my welding was worse then with my 20year old transformer based no nonsense machine. Now i know Lorch Saprom S3, Lorch V24, Hypertherm 65
Reply:One issue with gas is location.In America, 75/25 Ar/CO2 is very common and more importantly, commonly available in smaller, exchange bottles (in my area 80cf bottles).  I can also easily get pure CO2 or pure Argon.  If I stick to these quantities I can get away with paying roughly $30 to fill an 80.Any other percentage and its either rent a big bottle or pay for a custom fill (which seems to be about 2 weeks and $65).I understand in Europe 80/20 is more common.I have 90/10 for pulse and can tell you that with short arc it gets very 'ropey' if you use the recommended settings.  70s6 wire.  I find it relatively sensitive to turning up the heat.  So I go from 18V to 18.5 and I find I'm racing the puddle to keep from burning through (wire speed increased as well).   C25 seems to be less sensitive.Higher argon % might make arc starting harder.  Both my MIGs have pretty good arc starting characteristics so I don't know for sure.Anyway, the more CO2, the hotter.  The more O2 the hotter.   The more CO2 the more spatter (not sure about O2 and spatter). For car bodies, smaller wire and C25 seems to work well enough.  I'm pretty sure you don't want to do out of position spray arc - that tends to be thicker stuff in the flat.  I find spray arc to be more like spray painting metal.  I personally want to see the wire hit the puddle.Oh, BTW, pure Argon is the recommended gas for aluminum.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Did some pulse today, no prob with 82/18 gas. The one in the middle is normal mode, left and right is pulse. I didnt care for endcrater, just stopped   The pulse welds are more smooth.Material was 4mm mild steel, top number = volts and number below = meters/minute (10.8 = 425ipm), 0.30 wire. Dont remember the amps, think it was around 125 to 140.Youre right, in europa the 82/18 gas is quite common. But its also possible to get 75/25 without problems. Refill here for 20 l bottle is about $50 ... for 10l bottle its more or less the same price... No quantities and special pricing. Attached ImagesLast edited by tomelgato; 04-04-2013 at 10:16 PM.Lorch Saprom S3, Lorch V24, Hypertherm 65