I've recently started on my third AMT refit model (and my first since 1992 when I was 13, so I want to do it properly this time, although I'm very much an amateur). I gave it a Tamiya gray primer spray, flat white base and then a pearl white gloss. However the hand painting isn't looking good and I'm wondering why. I'm using Humbrol enamel and it seems to be very watery and inconsistent. I gave it a good shake and a stir. Is it the fact I'm painting onto gloss? Should I be using Acrylic? Does it just need more coats?