I did not do any special prep other than having a clean surface.
Sprayed some paint into a plastic container, then applied it with a foam brush. I did not apply any to the lid, only the bowl.
I suppose I could have looked for paint with a higher temperature rating. I used this stuff.
The transformation … Looked like new.
Some of the bowl now looks like this.
My main reason for using the paint was to cover up some JB Weld that was used to fill some small holes. I then got carried-away.
It doesn't bother me … It's a great cooker. Probably use it the most of all my kettles.