Posted for Kyrilian Dyer <kyrilian_av@yahoo.com>:

 Thanks Bill, and all the others who commented.  Since I don't have easy
  access to compressed nitrogen and don't think I'll need to buy a tank/
  regulator setup for other needs (oleo, etc) anytime soon, I think I'll just
  use compressed air.
 
 Bill&Sue <5zq@cox.net> wrote:<snip>
 My suggestion would be to stick with regular air. Use the money you'll save
 to buy avgas.