several steps
(1) with experience you learn to glue your armour pieces together better
(2) to fill holes and gaps - I used acyrlic caulk. NOT silicone. Its the stuff decorators use
foam based helmet
acrylic caulk applied and smoothed with fingers and a touch of water (its not an exact science)
like all filling - thin layers often, rather than a big dollop of the stuff.
It will take some light sanding too
Then I prep for painting. I use simple watered down PVA glue. Slight watering down so it sticks, but primarily I think its enhances paint adhesion (although I suspect some of this is in my head). I tend to put 3-5 layers of this stuff, allowing complete drying between
added bonus is that it seals the foam as well, so it doesnt have a porous texture
primer
paint
paint I use with car rattle cans.
I tend coat in plastidip at the end - either gloss or smoke depending on the effect I want.
this tends to add a flexible covering over your paint reducing cracking of the paint job
same technique on the full build
