.... so can I use CO2 or Argon?
I am MIG welding together two pieces of 3 mm mild steel, on highest setting 
and was recommend that Ar/CO2 would be better than CO2 (both of which I
have).
Would either of those gases be as good/ok?
Also how far to I unscrew the gas regulator - it goes to about 6 (?), I run it at around 3-4. (clarke welder).
I am welding inside a garage.
I use the little CO2 bottles for everything (everything steel that is). Apart from being just as effective as Ar/CO2, each bottle lasts about 5 times
as long.
Argon is for pansies. 
[Edited on 12/5/09 by AdamR]
CO2 is fine for steel. I'd consider it rather flamboyant to use the expensive stuff for steel!!
I would say that the best thing would be to experience all combos and see which works best for you.
Do you know anyone with a bottle of Ar/CO2 you can borrow for a test session?
Personally I need all the aid I can get so I use a rented BOC argoshield jobby.
I always use mix in the workshop and at home, find it gives a much cleaner weld with less spltter etc.
Matt
hey - do screwfix or B&Q sell these little bottles?
co2 runs a bit hotter ive found, so it gets better penetration on thicker welds at max power, trade off is the welds look a bit sh£t
Al
B&Q do - i dont know about screwfix
machine mart too.
^ I know, that is where I buy it from .... but MM is much further away.
If you are concerned about penertration, have you V prepped the joint?
Those little bottles are a waste of time, get a pub co2 cylinder. The little ones only seem to work with the tap FULLY opened, anything less is like a
mouse coughing on the weld puddle.
No point using pure argon, a co2/argon mix would work well, as would just straight CO2.
Post up pics, I'm sure there are plenty of people on here who could offer a few tips after seeing the results.
Oh, and as to the avatar - what an exceptionally lucky saddle 
[Edited on 12/5/09 by Dangle_kt]
quote:
Originally posted by Dangle_kt
If you are concerned about penertration, have you V prepped the joint?
co2 will be spot on for welding, but just think about what you are doing to the environment! 
absolutely nothing!
quote:
Originally posted by blakep82
co2 will be spot on for welding, but just think about what you are doing to the environment!
absolutely nothing!
I actually find it easier to set up my MIG on CO2 than on CO2/Argon mix. With the latter the wire seems to melt well before it hits the weld pool so
you have to wind the wire speed up, and you don't get such good penetration.
I can't understand why people have such problem with the little bottles though. They are clearly are not an economical way to run the welder for
heavy use, but my MIG works very nicely with the regulator just cracked open enough that I can only just feel the gas flow if I hold the torch close
to my face.
I certainly don't need to max it out.
I tend to use 100% CO2 as my welders a bit marginal and I prefer the greater wallop provided by that over an argon / CO2 mix. Ain't the pretiest
weld but that's mostly my fault not the choice of gas