Curious for views here.....

I was low on gas pre the bank hols, couldn't get argosheild light, so picked up a cylinder of pure argon.

When I changed them over there was quite a difference in the "Feel" of the weld, it was almosts as thought the welder was turned up a notch or too ?

I know you can MIG weld with CO2 Argo Light and pure argon, but can anyone actually exppain the real tech difference between argos light vs pure argon....can't belive that both myself and mate helping both imagined it

Nige

As far as I understand it.....the weld pool is hotter with pure Argon because CO2 actually cools the weld pool.

Thats as about as technical an understanding as I have. Maybe the Welding Stig will be able to shed some (UV) light on the subject

Dollythelw will be probably be able to give a more definitive answer, but the difference lies in the form of spray transfer in the molten weld pool. CO2 wil give more spatter, lesser controllable weld, but deeper penetration and a more convex bead shape. With CO2 it is actually not MIG but MAG, because the CO2 is not inactive.

Argon will give a finer looking weld, and because of the different spray transfer pattern it is often possible to use lesser amount of welding wire for the same job seen in comparison with CO2 welding.

Also, welding with argon will (not on stainless) give lesser amount of unhealty welding fumes

With argon the weld is MIG, because argon is inactive.

Addition of small amounts of hydrogen and - in some circumstances - oxygen will also be able to improve the weld quality for certain jobs on certain materials. For more exotic materials it is equally important to choose the right shielding gas, as choosing the right rod for ARC welding.

Can dig up more information from some of the old textbooks, if required.