I picked up a set of triple pipes for my 'old' Mountain Max sled. I want to blast and paint them, but they are pretty thin walled. What would you guys suggest for a media to use? I am NOT skilled with a sand blaster, so I don't want to punch thru the pipe wall. What do you guys think would be just enough as far as the media? Would walnut shells work? Or should I go with glass bead or a plastic abrasive? All comments are welcome.