So I had ago with PVA glue and a HD pep and you end up with a great finish on the armour part. It's a great finish and you get a good symetrical shape but on the other hand you end up spending plenty of time on the build!
I then went and used a foam template file of a Iron Man MK 3 helmet and used corrugated cardboard which was a really quick build and finish but you loose so much shape and lack a little in symmetry and some parts bulge out more than others. I've contemplated using foam but I want to Fiberglas and bondo the helmet afterwards.
And the girlfriend been a genius said why don't you use cereal boxes! So I laughed and said don't be silly dear! Anyway as soon as her back was turned I robber a load of cereal boxes from the kitchen and I turns out it works so I may be using this method from now on in!