I used a product called Slip Plate Graphite lubricant. Sandblast the manifolds, spray a few coats of Slip Plate on, let for 24 hours and buff the paint with a cotton terry cloth. Works very well. Stays on, does not burnoff or flake off. Far superior than the Cast Blast paints I used in the past. I did my exhaust manifolds 3 years ago and they still look great.