Cutterhead cooling gas-medical grade Helium

[dcknuth]

Hello to all,

Has anyone else in the US experienced difficulties in obtaining Medical Grade Helium for cooling a cutterhead on a VMS-70? My gas supplier informs me that there is a new government restriction, and that it now requires a medical license to buy.. if you can even find it in stock. Any alternatives??

Thanks to all!

[Aussie0zborn]

Not sure why you would want medical grade helium.
The Neumann manual recommends always buying the cheapest grade possible.
The helium simply fills a gap and helps to transfer the heat to other parts of the cutterhead.

[dcknuth]

Thank you for the reply AussieOzborn. I guess I've been under the belief that the cheaper helium contained moisture and other impurities that could conceivably contribute to corrosion inside the cutterhead.

I'm pleased to hear otherwise as I have plenty of other things to spend money on now with this project

Thanks again.

[prof msg]

I too have heard that balloon grade helium can contain moisture and ferrous debris that may be detrimental to the head. Is there a consensus about this? Is medical grade overkill?

-kp

[evildrome]

Buy Helium for TIG (HELI_ARC) welding. It is five 9s dry (for the obvious reason that water f**ks with making a good weld).

It will not corrode any metal parts as it is used in hideously expensive metal welding equipment and the gas supplier does not want a queue of enraged welders at his door.

Probably best to avoid the balloon stuff as it could have anything in it.

Just google "welding gas supply helium <your local area> " where <your local area> is umm... your local area.

Cheers,

Wilson.