AR/CO2 mix from MIG soldering

[sl4ck]

I wonder what can i do with the AR/CO2 mix used @ MIG soldering, can i use it as refrigerant, or else to brazing purge?

Do you know what gas i'm talking about?

Thx ;)

[aasmaukr]

It could be used as a refrigerant, but you would need a very low temp to condense it.. Condensing temp for R740 (Ar) is around -155 at 10 bar. But it's nice for purging.

Edit: I mean -155*C.

Btw, here's a pressure/temp chart for Argon: Link (http://images.godmod.net/kokue/datenblaetter/km/pT/R740.GIF).

[sl4ck]

ok, but do you know what mix i'm talking about?
And do you know the ratio of each gas is used AR/CO2 is used on those tanks?

Maybe it has a small % of AR(argon) ?

[aasmaukr]

I don't know exactly, but at least here in Norway, i think it's usually around 80/20 (Ar/CO2).

[sl4ck]

hummm, having ethylene has a 2nd stage gas, Argon maybe is a good 3rd stage gas?

[aasmaukr]

I don't think it will condense in a third stage, it's like 15 bar at -148*C. I think it would work better in a five-stage. Sth like this maybe: R402a/R1150+R170 blend/R14/R50/r740 :) Hehe, and that's difficult..

[n00b 0f l337]

Your above blend won't work in an autocascade, the argon will seep into the liquid r14.

[sl4ck]

so, in the end it is only usefull to purge while brazing.

[wdrzal]

The price of nitrogen is so much cheaper, I don't know why you waste expensive gases on purging. you can buy 40cuft bottles and regulatorss on ebay for under $100.00. you will reclaim that quickly in gas expendatures.

ya 80/20 0r 75/2......argon/co2 is used for mild steel

pure argon for aluminium

guys be carful for mild steel there is a gas mix called "starz" its something lts some like 78/20/2 with the 2 being 2% oxygen. this is added to the mig gas and usefull for welding thick steel 1/2+++,the o2 creats more heat to be sure you get a good penatraion. Do not use this mix in refrigeration.

[sl4ck]

The price of nitrogen is so much cheaper, I don't know why you waste expensive gases on purging. you can buy 40cuft bottles and regulatorss on ebay for under $100.00. you will reclaim that quickly in gas expendatures.

ya 80/20 0r 75/2......argon/co2 is used for mild steel

pure argon for aluminium

guys be carful for mild steel there is a gas mix called "starz" its something lts some like 78/20/2 with the 2 being 2% oxygen. this is added to the mig gas and usefull for welding thick steel 1/2+++,the o2 creats more heat to be sure you get a good penatraion. Do not use this mix in refrigeration.

Thx about the O2 info wdrzal ;)

The reason i asked this it's because here im Portugal, Gas companies only refill they're own bottles rented or buyed bottles, and thy're not something like 100$ if we choose to buy, if we choose to rent, we have to make at least 1 year contract, wich is more expensive than buy a new one, and my father has those bottles (AR/CO2) rented for MIG Solder, and i was planning to use it somehow.

[Blaster]

you can use it for purging

you can buy disposable bottles of N2 also and dont pay rent for it

[sl4ck]

How much N2 disposable tanks have and who has them?
Price?

Thanks