I have a large dark with railings stained with semi-transparent (can says 100% acrylic formula) stain. The color is Bordeaux, a deep redish/purple. We would like to redo the railings white, and are thinking a solid stain. What do I need to do for prep work? Also, I am not opposed to painting if it will save me hours of stripping. Any help would be greatly appreciated.

I've bought 30 odd new shelf brackets, which are white (I think they're painted in a white gloss of some kind) . I need to paint them black and I have some black Hammerite smooth spray paint to do this. However do I need to add a primer or something similar to get the paint to stick on, or is it just a case of doing 4 light coats as mentioned on the instructions? I'm concerned that the paint is going to be uneven and drippy as I don't think it'll take. They'll just be used indoors. I obviously want to avoid having to sand them all although I don't mind if it's just a light sanding, I guess it won't take that long. Any advice appreciated! Louis