This is the principle behind atomic hydrogen welding. An electric arc converts the hydrogen to atomic form, which recombines to molecules when it hits the surfa

This is the principle behind atomic hydrogen welding. An electric arc converts the hydrogen to atomic form, which recombines to molecules when it hits the surface. The hydrogen is also strongly reducing so you don't need flux. It still has some niche uses but it's not used much now because of risk of hydrogen embrittlement. There's an interesting instructional video about this on Youtube: https://www.youtube.com/watch?v=uZwYMyHlWXk https://www.youtube.com/watch?v=uZwYMyHlWXk