I'm just finishing up here at work, so gimme a few hours to get home and I'll walk you through it
Hows that?
In the meantime, essentially, to achieve welding sparks, you simply emit particles via a directional or omni emitter at the time your animation requires it
We will go over using:
-The Hardware Renderer
-Hardware particle types
-and more
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com