Percentage of gas mix for mig welding mild and stainless

[Craigybaby37]

Evening, I made a call today to someone who call fill me up a bottle of c02/argon mix for mig welding but I need some info on what percentage mix I need.

I have looked at some disposable mix bottles on eBay and they 80% argon 20% c02 is that about right for welding both mild steel and stainless upto 6mm thickness??

Thanks

 

[backpurge]

20% CO2 is far too much for stainless, you are looking at more like 2.5% but this isn't going to be enough for mild steel over a couple of mm thick

 

[Craigybaby37]

Ok so maybe it would be best I get a bottle mixed for each then? What percentages would you recommend for each??

Thansk

 

[backpurge]

2 5%CO2 in argon for stainless and 12%CO2+2%O2 in argon for mild steel

 

[Bill Edwards]

I think the normal mix for thin steel would be 95% argon, 5% CO2 - i.e BOC Argoshield Light.
I can't say what that would be like for stainless though, but it's good on steel under around 5mm thick.

 

[KemppiFrog]

I use 8% Co2/Argon for steel and it works very well. I will admit to laying a few stainless welds with it too, but not for clients. In another post, I tried it for Ally, and got a half decent result. But pure Argon was definately the right stuff for that.

 

[Jan]

The tendency in the UK is to go for a 5% or lower CO2 mix with an occasional 2% O2 just to make things interesting. For no obvious reason the Yanks seem to prefer 20% or more CO2. Perhaps it's related to them mostly only having access to 110/120 volts as a 'mains' electricity feed.

 

[shenion]

The tendency in the UK is to go for a 5% or lower CO2 mix with an occasional 2% O2 just to make things interesting. For no obvious reason the Yanks seem to prefer 20% or more CO2. Perhaps it's related to them mostly only having access to 110/120 volts as a 'mains' electricity feed.

It has to do is we refuse to pay for tri-mix when C25 is cheap and is certified for industrial uses. No need for rental or expensive mixes, we have work to do and the bottom line drives needs.

We don't have only "120 volts". All houses are wired with 240V spit phase. Most are 150A service with 200 being the norm these days (and 400A on big houses.)

 

[Andy1428]

We don't have only "120 volts". All houses are wired with 240V spit phase. Most are 150A service with 200 being the norm these days (and 400A on big houses.)

US houses are wired with single phase 120 / 0 / 120 supplies. 120V is available for small appliances, but 240V is used for higher current usage, tumble dryers, air con compressors etc. It is actually a sensible system. You are much less likely to kill yourself with 120V than 240V, yet 240V is available for high current draws.

 

[Jan]

I wasn't aware of this. That's very handy as many industrial tools are available in 110/120 volt formats for much the same price as hobby tools of a lesser quality.