Argon / C02 Mix - confused

[Podder]

Hi all,

I am looking at getting my gas from Adams as this seems the best deal for me. They do 80/20 or 95/5 Argon/C02 mixes. My first thought was 95/5 as this is similar to Argonshield light and most of my welding is car body repairs, but reading the percentages review by Shenion, the best welds seemed to come from a higher proportion of C02.

Any advise most welcome

Cheers, Nick.

 

[backpurge]

Definately go for the 95/5 mix for car body work.

The higher the CO2 content the hotter the arc/weldpool. 80/20 is designed for material above 6mm thick which you would be welding in spray transfer

Dependant upon who's gas is in Adams cylinders and the grade of argon used you could well find there is a couple of percent O2 in there as well (same as Argoshield) which helps with wetting and spatter generation

 

[KMpuggy]

Id say same as above. I had the same thought when i ordered some from them, using it the same as you on car body, so i just asked them and they gave me a bottle of 95/5.

 

[Bsmith]

95/5 is also the better one (although not perfect) for welding stainless steel too but for the life of me I can't remember why.

 

[backpurge]

95/5 is also the better one (although not perfect) for welding stainless steel too but for the life of me I can't remember why.

It's due to the lower oxidising content of the gas although you will get a far better result with Argon + 2.5% CO2, a lot of people still use Argon + 2% O2 but to be honest it is crap compared to the Ar/CO2 mix

 

[Podder]

Excellent, thanks for the advice guys.

 

[shenion]

95/5 is tri-mix: Argon/CO2/O2. (95/3/2)
80/20 is Argon/CO2.

They are about equivalent. O2 has about 8 times the effect of adding heat as CO2.

95/5 of just Ar/CO2 would produce very tall welds unless you used spray transfer.

 

[backpurge]

95/5 is tri-mix: Argon/CO2/O2. (95/3/2)
80/20 is Argon/CO2.

They are about equivalent. O2 has about 8 times the effect of adding heat as CO2.

95/5 of just Ar/CO2 would produce very tall welds unless you used spray transfer.

Sorry fella but can't agree with you there,95/5 isn't necessarily a tri mix, you can get straight 95/5 mixes with no oxygen.

95/5 and 80/20 are no way equivalent, one has 5% CO2 and the other has 20% CO2 and as such will behave totally differently

Oxygen transfers a lot less heat across the arc than CO2 with double the oxidation, it also has a totally different effect, CO2 works down in the body of the weld pool increasing penetration/fusion etc whereas O2 tends to effect the surface of the weld pool reducing surface tension, improving wetting and reducing spatter generation

95/5 will produce tall welds if you don't have enough voltage or if your wire feed speed is too high but you get the same regardless of what gas you are using

Seeing as 95/5 is only really recommended for sheet steel you wouldn't be welding in spray transfer anyway