Firstly, let me state that I'm no chemist. My specialty is in thermally applied coatings such as electric-arc metalizing.
During the course of my career I've always been presented with vague warnings to use "proper" ventilation to prevent hydrogen buildup within a contained area when spraying Al alloys.
Could someone please explain the process that creates hydrogen gas when arcing between two Al electrodes?
Also, what would the "proper" ventilation be? Would dry dust collection/ventilation suffice or would wet collection methods be required? Would this same reaction occur when using other alloys commonly used in thermal deposition processes?