Howard wrote:
I googled a bit for this subject, but can't find specifics regarding
radiators,

Is it recommended or not, to use spray on Hammerite (gloss white) on a
bathroom rad?

Never tried Hammerite itself.

There are special radiator paints out there. I've tried two, a brush-on
type that was truly foul to use and it gassed horribly, and a spray made
by "Plasti-kote". Whilst this is not particularly nice to use, it a) is
less offensive, and b) covers pretty well. Dries in an hour.