- Thread starter Drav
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You're spot on Archie, although I think Drav is using disposables? & they only seem to be available in that mix 
5% is generally regarded as the best gas for thin sheet...BOC Argoshield Light or equivalent (actually 3% CO2, 2% Oxygen & 95% pure Argon).
weldequip
5% is generally regarded as the best gas for thin sheet...BOC Argoshield Light or equivalent (actually 3% CO2, 2% Oxygen & 95% pure Argon).weldequip
Good good. Always nice to know I'm not speaking out of you know where the entire time! 
That seems a bit daft though. Surely the majority of disposables are used on car bodywork and other fairly thin applications, so you would have thought they'd have the percentages matched accordingly. I suppose CO2's cheaper so they bung as much in as they can get away with!
That seems a bit daft though. Surely the majority of disposables are used on car bodywork and other fairly thin applications, so you would have thought they'd have the percentages matched accordingly. I suppose CO2's cheaper so they bung as much in as they can get away with!
malcolm
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I didn't notice any difference between argoshield and the disposable bottle mix in the sort of welding I do. Apart from the cost of disposables for my short test. North Americans seem to go for higher CO2 mixes, so I guess the ratio in the disposable mix has come from over there.
What's this talk about not grinding down tack welds being the cause of poor penetration in that flat butt weld. You missed the join there!
What's this talk about not grinding down tack welds being the cause of poor penetration in that flat butt weld. You missed the join there!
shenion
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weldequip said:
You cant compare straight Ar/CO2 mix to argoshield.
Argoshield has O2 that has about 5x as much of effect as CO2. Remember, part of the CO2 breaks down to O2 and CO anyway.
Looking at the weld pics, argoshield light matches the weld profile I did with 85/15 mix. the 5:1 effectiveness of O2 makes 95/3/2 approximately equivalent to 87/13 Ar/CO2.
malcom said:
Ar/Co2 is 75/25 here called Argoshield C25 here (they had to put the argoshield name in there
). It is the standard for short-arc welding. Tri-mix is not popular here. Lots of flack about negative effects of O2 (fast cool of deep weld pool trapping O2.) 75/25 is preferred also because it helps prevent globular and spray transfer. Better for positional welding. Did not think much of it until I saw someone doing 175A short-arc vertical welds. 75/25 kept the weld mode stable in short-arc (Millermatic 211). Any lower CO2 went into globular/spray transfer.
My tests had a perfectly symmetrical weld profile top and bottom with 75/25 mix on 1mm steel.
For spray-transfer 92/8% seems to be common. Usually it is 5-12% CO2.
Ar/Co2 is 75/25 here called Argoshield C25 here (they had to put the argoshield name in there
That would be Argoshield 'Heavy' here, used on thicker section welding. Tri-mix is also increasingly popular in Europe. I was informed that Synergic Pulsed MIG is relatively 'new' in the States, whereas it's been around for a while here in Europe & is now a bench mark for many processes. Not saying anybody is right or wrong, just interesting the differences of opinion/techniques used.
weldequip
shenion
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Pulsed MIG has been here a long time (early '70s). However, early adopters got burned with it (read weldreality.com). It lowered production rates, and weld quality suffered. I saw a lot of the old Miller and Lincoln pre-2000 pulsed MIG units on ebay. Fab shops were dumping dozens of them.
So, looks like most production went spray transfer. That meant robotics need to move the work to stay horizontal welds. Does have the highest productivity.
The 175A vertical I mentioned was and excellent example where pulsed would help. Spray transfer would be fast but not work on vertical. Thin metal and the area between short-arc and spray transfer is where Pulsed MIG shines along with advanced things like alum and brazing. The shop that was using it was low budget (they were looking at using my CP-250.) No way they could afford a high-end machine.
So, looks like most production went spray transfer. That meant robotics need to move the work to stay horizontal welds. Does have the highest productivity.
The 175A vertical I mentioned was and excellent example where pulsed would help. Spray transfer would be fast but not work on vertical. Thin metal and the area between short-arc and spray transfer is where Pulsed MIG shines along with advanced things like alum and brazing. The shop that was using it was low budget (they were looking at using my CP-250.) No way they could afford a high-end machine.
