Mison Gas

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Mison Gas - any experience?The instructor of my arc-welding class raves about MIG with Mison shileding gas.  At his work place, a Linde salesman gave a demonstration of this specialty gas and according to him everyone was amazed... faster weld speeds, low splatter and superb bead appearance.  He told me to check it out on google.According to info on the web, the gas is marketed by AGA and now by Linde.Mison gas appears to be a typical Argon/CO2 mix but with the addition of a nitirc oxide.e.g. Mison 18: Composition: 82% argon, 18% CO2 and < 0,03% NOHere's a few quotes from the web..."The small amount of nitric oxide gas in Mison has a stabilizing effect that aids the welding process by constricting the arc. While we don't totally understand the exact mechanisms at work, we believe the nitric oxide acts as a scavenger in the base argon and on the surface oxides of the metal.""We have found evidence of arc starting and stability improvements, which translate to smoother welds and less spatter--even in manual welding operations," “provided a superior arc start and more stable arc that enhanced the weld appearance at faster welding speeds than would have been possible using the argon.”“We are now able to put down nicer welds and at the same time increase weld speed.”There was a thread of this ("Mison 20 gas") here back in Jan 13 2007.http://weldingweb.com/vbb/showthread.php?t=8563At that time the consensus was it was 'snake oil' and offered no real improvement.However, my instructor is no dummy and he went yaking on about this Mison gas last week - saying it made a so-so welder look good and a good welder look like an expert!Thus, if my instructor says it's super stuff and his employer willing pays the extra 30% to use it over C25, then... it's got to be more than hype for 'snake oil'.Heard anything?Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Not really any real info to go on. I'd suspect like most "specialty" gasses it needs more volts than most small machines are capable of producing.  If he's upping the volts and going into spray from short arc, the faster weld speed, lower spatter and better appearance would all make sense. You could also probably get the same results with say 92/8 argon/co2 if you set the machine up right.I'd want to know the same things we usually ask to see when people post up questions... Material and thickness, position ( flat, horz, vert, overhead), model machine used and settings as far as wire speed and volts, wire size and type... both what was used before with the old gas as well as those used with the new gas. Picts both with the old gas and new gas would help to evaluate the differences.Salesmen are there usually to do one thing, sell stuff, preferably stuff that they make the most margin with. If they can convince you the "new" tomato is better than the "old" ones you are eating now, and can make more money on the new ones, they'll "rig" the test or demonstration in such a way to get the results they want. It's rare you actually find a salesman who's interested in getting a customer a better product that has a lower profit margin for his company. If that's the case he usually knows that he'll get more sales so that he makes up the profits in volume..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 really have a hard time believing that <0.03% has any dramatic effect on the arc, or that its not something that could be reproduced by a 98/2 or 95/5 mix.  Those are touted for the same reasons, fast travel speed, low spatter and constricted arc..03% is almost in the realm of being considered a tramp element.Sounds like a good way for them to charge more for selling essentially an 80/20 mix.Have we all gone mad?
Reply:Nitric oxide is a very reactive molecule... Some constructional alloys really behaved poorly after being plasma cut back in the day nitrogen was used a lot. I'd want to see if that small amount doesn't reduce the iron content a bit and alter the intended filler metal properties???It matters only if it can serve to pay for itself by increasing speed or quality. Going anal with mig appearance is a good way to work yourself out of a job sometimes, if it slows things down.Matt
Reply:I have welded with some of the Mison Gas mixtures.  Linde makes Mison mixtures based on  75/25 85/15, 98/2, and 90/10(I think) Ar/CO2.  The small addition of nitric oxide does affect the puddle behavior.  To me, it seems a little more fluid, or maybe improves the ability of the puddle to wett into the base metal(stainless steel).  I've not done any welding  with Mison gas on mild steel.I would not claim dramatic improvements in arc starts and arc stability as a universal benefit.  Perhaps in some circumstances there is some improvement, but I've not seen it when I used Mison 2C (98Ar/2CO2) while welding stainless steel.I also doubt claims that it turns unskilled welders into welders with amazing skill.  Welding is all about reading the puddle, and equipment won't make up for a lack of experience.I'll second Matt's comments that addition nitrogen and oxygen to the weld pool can have undesireable consequences for the mechanical properties of some welds.  Oxygen and Nitrogen can have strong influence on impact toughness through promotion of the formation of oxide and nitride inclusions.  It's a case of "a little is good", but too much is bad.  It depends on the base metal chemistry, atmospheric and surface contaminations, and heat input.  Maybe it does nothing in one instance, but maybe it tips the weld chemistry 'over the edge', and you see hot cracking or embrittlement.All in all, a 30% price premium for every day welding is a waste, IMO.  And just switching shielding gases can force requalification of a company's welding procedures; not something to be done lightly or 'played with' in the field.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector