paint "patching" problems

I get "maps" after a smooth wetcoat on specific areas... i have sanded down these areas to primer then slowly build up with about 5 mist coats every 15 mins before doing clear coats after a day of drying. they always come back.

I have "restored" this kit from a Brake Fluid bath and ceramic epoxy fillers.

any suggestions?

You can get a special primer that acts as a barrier coat and seals the plastic so should prevent what you describe. You then apply your normal primer over this and paint as usual. Only place I've seen it is Hiroboy. It might be worth a try. I think maybe the brake fluid bath may have caused you the problems as I've had that before when I've stripped with it. I only use Iso alcohol now and never have the same problem since..

http://www.hiroboy.com/catalog/product_info.php?products_id=3534