hi
I am using a fiberglass mold. and I apply Gelcoat with paint on it. but after several time surface of the mold is matt and is not glossy and someplace when I watch the surface of the mold I can see some Gelcoat and paint cured on the surface mold. please help me how can I remove it?
in this area when I apply again new gel coat and paint it become matt and final products in some area is matt.

please let me know how can I clean the surface of the mold?
before I used some kind of acid and also acetone but nothing happened.

tanks so much

If mould cleaner or similar does not clean it off, then you may need to lightly sand the surface to restore smoothness then polish it back to a high gloss before starting afresh with release agents. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant