system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If flux keeps hot metal from reacting with the air when welding, what protects it from reacting with the water when welding underwater?
gpt
It actually makes a "bubble" of gas around the weld site, pushing all the water out. And actually, it's the exact same principle in air too, but instead of pushing away the water it pushes away the oxygen-rich air. You just can't see the "bubble", but it's there.