Yesterday I started making a mould and only went as far as gel coat and first reinforcement layer but then something came up and I had to leave in a hurry. By the time I came back, the mould was already cured and rock solid. I was wondering it I can keep on reinforcing the mould  with subsequent layers even after the gelcoat and first layer have cured? Would it delaminate? It's a pretty big part and I've used quite a bit of material even this early so it would be costly if I had to start all over again. 

If you sand your last fiberglass layer with a 80grid sandpaper and work further on that surface it should be ok

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com