If the door is currently GF gel coat without a paint finish then start by rubbing it down so the paint has a key. Paint with an etch primer which eats into the surface. Paint with whatever paint finish you choose as long as it is compatible with the primer.
thanks for that advice. The doors are currently painted I just want to give them a refresh. I was thinking of just rubbing them down a little but am unsure of what type of paint to use?
Dulux trade external gloss. More expensive than most but in this case you do get what you pay for. The original paint must be secure and not flaking. If it is then you will have to rub it all back or it will all come off again.
It's also a good idea to make sure the surface you're about to paint is clean, for this type of painting i'd use stuff called 'sugar soap' you can get it from places like B & Q
