KemppiFrog
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It seems HobbyWeld put a bit of O2 in their MIG mix. The question was about MIG/ MAG gasses. So what effect would that have?
CO2 is an active component, MIG uses totally inert mixtures such as Ar and He (apart from “doped” mixtures which have ppm levels of O2)Most MAG (Metal Active Gas, the oxygen being an active agent in the mix) gas mixes have a bit of oxygen in them. MIG (Metal Inert Gas, usually Argon, Helium and CO2) gas for stainless hasn't got any.
With respect Al I was always led to believe 2 parts CO2 equaled 1 part O2 but it’s all smoke and mirrors to me to be honest!!Most of the Ar / CO2 mixes contain 2%O2........as far as Im aware its cheaper for the manufacturers as they dont have to remove it........some do special Oxygen free...but in reality its the Oxygen thats the ACTIVE part of the MAG name....Ive always worked on 1 Oxygen = 3CO2......so the 2% is like adding 6 parts CO2 so it makes it Argon 24% CO2........In America 75/25 is the common mix...without Oxygen
to be honest i wouldnt argue as it depends on thermodynamics (entropy) which are energy and temperature dependent.......theres a good chance there are settings where we are both correct...same for CO2 as it relies of dissociation into CO and O2......which again is dependent on settings / temperatures etcWith respect Al I was always led to believe 2 parts CO2 equaled 1 part O2 but it’s all smoke and mirrors to me to be honest!!
Al, your comments about cost are mainly correct though, some companies use industrial grade argon which has around 2% O2 in it, whereas others make a true 3 part mix which uses high purity Ar plus O2 and CO2, all depends on how they are running their air separation unitsto be honest i wouldnt argue as it depends on thermodynamics (entropy) which are energy and temperature dependent.......theres a good chance there are settings where we are both correct...same for CO2 as it relies of dissociation into CO and O2......which again is dependent on settings / temperatures etc
8% is a really niche mix in the UK, ESAB developed their Purus wire to run with it, then realised only Air Liquide carry it as a standard mix and even then they want £50 odd quid a bottle!Thanks all, I have not used MIG in the UK and here I use a 8% CO2 mix, no mention of oxygen.
KF