Ah ok. They were showing people putting on what looked like moon suits and going into a chamber. I imagine that's for smaller scale welds. But I imagine pumping

Ah ok. They were showing people putting on what looked like moon suits and going into a chamber. I imagine that's for smaller scale welds. But I imagine pumping argon under pressure to displace oxygen in some areas would work as well. Then ventilate properly as it would settle and well ... suffocate people.