Originally Posted by SubAtomicGenius
In my experience, the high heat paint simply does not work on automotive exhausts. Rust sets in quickly. You're better off not wasting your time IMHO.
I did the exhaust on my 2009 Patriot FDI, my 2012 JK and my 2013 JKU. My 2011 Patriot FDII was painted from the factory. A guy at work bought the 2009, 50K miles and the paint on that muffler still looks good. No rust. I didnt use primer on any of them. I did them when they were new. The Wranglers were done as soon as I got home from the dealer. I rub them down with 00 steel wool and clean them up with alcohol. After spraying I go for a ride, twice, to cure them. If the muffler already has rust it would be a whole different technique. If you dont remove the rust, it WILL come back. Do it from new, clean it good and cure it, it will last for years. (Unless you scrape it off...)