rusty brake disc, how to stop it.

[steve_bmw]

i see new ish vehicles on the road with factory discs and the hub part of the disc is still silver and rust free.

they look galvanised?

i am replacing the discs on the z4 and wonderd if i bought oem discs would they have the same protection on them as the ones supplied when the car is new?

when replacing disc's on my last car the hubs went rusty in about a week and looked tatty.

is there any special paint or coating i can use to get that factory protection?

i dont want to brush paint hammerite on that looks rubbish.

thanks

[steve_bmw]

thanks everyone for your help, zinc spray seems to be the best solution.

[steve_bmw]

done the disc's today with some zinc primer, nice finnish too.
used brake cleaner to remove the oil, then applied 4 coats to the hub and the outer part of the disc.
bit of a job to mask off the braking part of the disk, but the paint will scrape off using a stanley blade to leave a nice edge.