Gas for welding stanless Steel

[chooch]

Hi All

I have just bought a Clarke 151EN Turbo MIG to weld stainless steel (304L) for exhaust & manifold purposes. I phoned BOC & it was going to cost around £200 for Stainshield Light as it only comes in big cylinders.

On the Stainless steel welding tutorial 97.5% Argon +2.5% CO2 gas is recommended but is hard to obtain.
Ref: http://www.mig-welding.co.uk/stainless.htm

Stainshield Light is 13.5%Ar,85%He,1.5%CO2

I am thinking of using hobby gasses initially, but on the label of the following they state both gasses can be used for stainless steel
http://www.machinemart.co.uk/shop/product/details/argon-gas-cylinder
http://www.machinemart.co.uk/shop/product/details/co2-argon-mix-gas-cylinder

If one is better than the other I'd appreciate knowing & likewise if there are better options for obtaining gas cylinders.

cheers,
Ewan

P.S. Why does Air Products sell the same gas composition under Inomaxx2 & Weldap2?

Ref: http://www.mig-welding.co.uk/gas-composition.htm

 

[backpurge]

For Hobby type work I would not recomend the Stainshield Light mix as you will probably not appreciate the benefits.

You cannot use straight argon for MAG welding stainless steel, you need the addition of some active components, either oxygen or carbon dioxide. Ideally you dont want to have more than 2.5% addition, but as you say not many people do these mixes in small cylinders. Although I would never advise it in my proffessional capacity a lot of the guys on here use a 5%CO2 in argon mix and say it is acceptable, I would try and get a straight Ar/Co2 mix and not something like Argosheild Light which also contains 2% O2

Re you question over APL's naming of gases, as far as I am aware it is down to them trying to standardise on product names throughout the world and they haven't re labelled all the cylinders yet, but I could be, and probably am wrong

 

[chooch]

thanks for the reply blackpurge.

Does anyone know where I can go to get a gas mix made up?

So to clarify Clarke has their advertising wrong for the argon gas, I should use argon C02 mix as a temporary fix.

Thanks,
Ewan

 

[langy]

BOC pure shield argon

 

[outofthefire]

I welded some stainless the other week and just used argoshield it welded great.

 

[backpurge]

BOC pure shield argon

Not for MIG, you need some CO2 or O2 in there as well

 

[backpurge]

I welded some stainless the other week and just used argoshield it welded great.

Depends on what end result you want/need

 

[outofthefire]

Depends on what end result you want/need

I welded the wings on to the body on the piece in this thread http://www.mig-welding.co.uk/forum/showthread.php?t=33661 not sure how it could have been any better it ground and polished out so the weld blended lovely. Before I ground it out the weld was good I just wanted it all to blend in.

 

[langy]

Not for MIG, you need some CO2 or O2 in there as well

Your right mate, thought he had a tig, just noticed its mig