Below the MR. Surface.

Okay, I have crumbled to peer pressure.  I have often heard tale of Mr. Surfacer and how cool it is.  As I was on Squadron refilling some paints and tools and such, I came across Mr. Surfacer.  I figured I'd try it, I ordered the 500,100,1200.  Simply put, you can never have too many tools!  Now that I have ordered it, can someone tell me what it does and how to use it?