I am having my brake calliper mounts water jet cut. What is the best paint protection, primer / top coat to keep them rust free after?
Regards, John.

A personal favourite of mine is to base coat with red oxide then plastikote top coat. I've found both paints dry harder and stronger with a little warmth on them - I've used an electric heater to do this.

The alternative is to have them shot blasted and powder coated. Obviously there's a cost associated, but it may give you the finish and protection you're looking for.

Zinc rich primer then normal top coat.

avoid shot blasting I had a really bad experience of it it was very difficult to get rid of the sand, would not like see anyone else with the same bother!