Exhaust manifold coatings

I used a product called Calyx on my cast iron manifolds when I restored the car last summer. After only 300 miles or so, all the coating is gone. NO trace of it anywhere. What do you guys use, or suggest I use, on my manifolds to give them that new cast iron look? Remember that they are installed in the car now, so I would only be able to do the tops.

Thanks in advance,

Author: admin