Here's the the main tools for the job.
A light disc sander on the cordless drill, also used a brush disc for some heavy parts.
High Temp Primer & Hight Temp Header Ceramic Coating.
You're not to coat heavily, you're only to coat to give color or else it will bubble.
Once dry to the touch you're to Idle for 10 min & cool, then 15 min & cool, then full throttle to bake it in.
Instructions say outdoor temp is to be above 20 degrees.
I brought it down to the sheet metal.
At Primer stage.
Finished product.