Comments by "Keit Hammleter" (@keithammleter3824) on "" video.

@stargazer5784 It was definitely an AC-style hum they added in. MIG welding with DC is a pulsating process and therefore makes a buzzing or humming sound, but it is a quite different sound, more erratic, lower in frequency. MIG welding is a pulsating process because the machine continually pushes out a thin wire (about 1 square mm cross section per 100 amps) - when the wire end contacts the job the current melts a tiny bit off the end, which cuts the current until more wire emerges and contacts the job again. But it is difficult to imagine how this would arise in a submarine battery room. There's nothing to steadily push out more wire. Stick welding with DC just makes a hissing sound as it is a continuous process.
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