Viperdoc schrieb:

You can use welding oxygen- see aviation consumer as well as the articles in

Be careful with welding oxygen. While it is true that all oxygen is made
in the same machine, it's treated differently afterwards. Welding oxygen
is just filled in whatever exchange bottle is brought back from some
unknown former customer without any control whatsoever. So you never
know what is *really* in the bottle.

If you bring and have refilled your own bottle and are absolutely sure
that is is really your own bottle which has been refilled, then welding
O2 should be fine.

What many glider operators do is to buy a big bottle of medicinal O2 and
refill their small bottle from it.