Gas

[500e]

I understand it can be beneficial to use a Argon Helium mix TIG welding alloy, (for welding material at the top end of your machines rating) it would appear that you get an apparent higher voltage weld with less cleaning\ polish required does this also work with MIG?

 

[shenion]

Ar/He mix will work for MIG. The welds would probably be a bit tall.

The only reason I have seen for Ar/He with TIG is for more heat in the weld not about cleaning/polishing.

Have you priced Ar/He? AFAIK it is several times the price of regular mixes as helium is expensive to produce.

 

[500e]

Thanks for reply
Was thinking of separate He. and mixing with non return valves & Y connection, the more heat in weld I understand, have seen it used for TIG but not MIG

 

[Hitch]

What are you migging up?

Theres various gas mixes for mig welding.....different mixes for different characteristics.....

 

[shenion]

I think i have seen Ar/He mixes for welding stainless.

 

[hotrodder]

Thin ally aside Ar/He mixes are nicer to use. As you say He increases the arc voltage (something to do with ionisation potentials) so transfers more energy to the weld- higher welding speeds, better depth to width profile and better side wall fusion etc. The ionisation potential/arc voltage thing makes for difficult arc starting with pure He hence mixing it with Ar. Downsides would be the cost of the stuff... helium is a finite resource, googling 'helium shortage' will get hits to various stories about the recent/current shortage etc

I think i have seen Ar/He mixes for welding stainless.

It's used in trimix/stainshield MIG along with a little CO2 for arc stability. For TIG and austenitic stainless a little hydrogen is added to argon- the hydrogen increases arc voltage and creates a reducing atmosphere making for cleaner welds and higher speeds. Like Ar/He alushield mixes they can be the more expensive way of skinning a cat outside of production work