For me, a very simple solution was to connect a leather bib.
This stops fumes to come through the helmet and avoids, in my case of aluminum welding, sun burn of the throat.
Another black cloth to keep the radiation off my ears.
Both can be bottoned off.
Don't be afraid of ....
This is of course no substitute for a proper mask.
IIRC the 3M disposable welding masks are no. 8835
They aint cheap though, good few quid each!