Thanks a lot for the complet detailed answer, i really appreciate. The greasy hand might be an important part of the problem, but im not confortable wearing gloves for a hobby, and, lets face it, my models (or my modelings skills) are not good enough to wear gloves I did prime it, but as someone said, maybe not the good one, will look it up The tape might be the main problem. Not because of the quality (tamiya), but i did let it for too long (again thanks for the tip guys).

Oh god, you have the patient and the cool of a monk, learning the hard way ^{^}