I haven't painted metal beds but with lot of crafts made with metals such as watering cans the books tell you to wipe it down with rubbing alcohol. Use a rag that isn't lint filled, or good paper towel/Old sock would be good. Then try not to be touching it so have it where you are going to spray the primer on maybe on a couple of stakes in the ground if it is hollow. That way you won't need to touch it. Oils in skin sometimes make paint not adhere(same with glass projects).The brass bed if real would be heavy & probably tarnished to brownish color. If it is really shiny it's probably not. Jan

I would also say that it might be best to lightly sand the beds first..that will help the paint adhere better.

I would use a special primer such as Bin or Kilz first.
Kathy

Thanks all for answering. I have decided not to use this headboard in my flower bed fence. It has one of the vertical bars missing. I am also not going to paint it. I will put it somewhere else in the yard and put a flowering vine on it.

Sharon