Every photographer's portfolio has to have the industrial "welder shot"... here's mine.
The main light is obviously supplied by the arc-welding equipment. I bounced a low-powered strobe from an umbrella from the right side of the camera position, this served to open the deep shadow just a little bit.
To help separate the subject's shoulder from the background, a strobe head (with a blue gel) was directed onto a white screen positioned behind, and to the right, of the welder.