The difficulty of photographing Welding is that the brightness of the arc causes underexposure of everything else and sometimes its good to throw some light back into other parts of the shot. The best way is to use multiple canon speedlites to help expose this subject and the brightness of the welding. This takes a lot of light to accomplish a beautiful image.
First decide on your basic, non flash exposure. The most important is to decide on what aperture you want to shoot at. The sparks from the arc will show lovely streamers if the speed is slow enough, say 1/15 and always using a tripod.
shaunmckenna.com provides Industrial Photography services for companies and their creative agencies and covers promotional, advertising, industrial machinery, plant, buildings, factories, people and offices and catalogue work for web and print use.
I will provide you with images that are both informative and eye-catching, for product brochures, display stands and web use and are happy to produce work to fit a preexisting manual or training guide.