- Thread starter LucasJ
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One of our members used to do that with a proper gas mixer but decided it just wasn't worth the effort plus the kit needed is quite expensive.
Why do you need a different mix than those readily available? The standard gases and mixes work for almost everyone else.
Why do you need a different mix than those readily available? The standard gases and mixes work for almost everyone else.
BrokenBiker
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i think it would be cheaper to rent them than to set yourself up to mix them properly
BrokenBiker
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i was wondering this as ive not seen many comercially available mixes with 5% o2
I want to weld normal unalloyed steel. Because I want to weld primarily thin sheet metal (1mm) I was adviced to get a shielding gas with reduced CO2. A 82/18 is still too powerful for thin sheet increasing the likelihood of burn throughs which can be attributed to the amount of CO2. So lowering the CO2 to approx 5% is good, and then you add approx. 5% O2 which flattens the weld much better than CO2 but with less heat input. I have never tried it myself but was told in a German welding forum to choose a mixture of that type: 90/5/5.
BrokenBiker
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just get something like argoshield light, comercially available from BOC gasses and is specifically designed for thin metal, i believe from 0.8 to 5mm
Lucas
I was taught that 1% O2 acts like maybe 3% CO2 so the gas you are asking for is probably the equivalent of 80Ar/20CO2
Usually the more rare mixtures like the 90/5/5 are for use with flux cored wires and then for a specific purpose
95/5 or 93/5/2 is what you want
And mixing it isnt easy........you dont only need the mixer you need analysis equipment to check the mix..........I know a very big company who decided it would be cheaper to mix their own..........they are continually having problems and when you check it the composition is different (wrong),,,,,,,and then they blame the wire but thats another story
I was taught that 1% O2 acts like maybe 3% CO2 so the gas you are asking for is probably the equivalent of 80Ar/20CO2
Usually the more rare mixtures like the 90/5/5 are for use with flux cored wires and then for a specific purpose
95/5 or 93/5/2 is what you want
And mixing it isnt easy........you dont only need the mixer you need analysis equipment to check the mix..........I know a very big company who decided it would be cheaper to mix their own..........they are continually having problems and when you check it the composition is different (wrong),,,,,,,and then they blame the wire but thats another story
backpurge
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5% O2 may be a bit high as it could lead to things like undercut due to increased weld pool surface fluidity, the norm is 2% max
Al, you're spot on with the gas recommendation but CO2 carries around twice as much heat across the arc than O2, it also reacts with the weldpool in a slightly different way.
Al, you're spot on with the gas recommendation but CO2 carries around twice as much heat across the arc than O2, it also reacts with the weldpool in a slightly different way.
As far as I know its called trial and error
