Painting a roll top bath

[NurseNancyandDoctorDavid]

Can any one help?

I want to paint our roll top bath exterior with Farrow and Ball Stiffkey blue, I'm just unsure which primer to use, I've spoken to F&B but their advice didn't add up as they suggested primer for wood and metal, even though the bath is acrylic. What they did say, is to use a water based primer.

Have any of you successfully done this, and if so what would you recommend?

Well, this won't probably won't really help you but I painted the exterior of a cast iron bath with the same emulsion that I used on the wall.

It is seemed to last OK. (and no primer!)