[sick472]

I have blasted a few sets of mani's and have always put masking tape over the machined surfaces. Blasting will make a differnce in how long the coating lasts, but it never really lasts as long as you want. I'm on the cheap and always used Rustoleum engine paint. It does better by following the instructions and using an oven to cure them, but it's still just paint on a hot engine component.