Minor rust under paint

[Gardner Yeaw]

I have a few places where there is rust showing through the paint, like
just below the Wanderlodge emblem on the rear and a couple of other
places. The worst is on top of the refrigerator vent cap.

I realize once started it is never completely stopped, but I am
curious what have others used to treat the affected areas before
repainting. Ospho is one product suggested, but is it good under
exterior paint? Are there other products that have given good results?

My current plan is to clean up the affected areas, treat them, and
prime them for protection until I am ready for paint. I live in the
North East, so I want to be ready for the winter (outdoor storage with
a cover).

Thanks,
Gardner
78FC33