I brought 2 packs at £6 each and this has made the whole helmet with some to spare incase i have a mishap and any color will do, whatever suits you.
I the rolled out the clay to a decent depth and started to layer it onto the head. Don't be too sparing with it, remember, this is the basic support structure to everything you're going to add after so it has to be strong.
You can blend it in by dipping your fingers in a bowl of water and smoothing the edges to merge.
You have no need at this stage to be neat, really whack it on and build up the important parts and always make sure its symmetrical. Work the clay smooth with wet fingers until its a rough shape of Ironmans helmet.
Once this is done draw on the edges that have to be sharpened up and add more clay to get the right angles your going to need in order to sand them to the right sharp egde shape after. Dont be too fussy as this clay sand really well.
Wait for the clay to dry completely then just go over the whole lot adding little bits of clay to fill in those little holes you think wont sand out and he should look something like the pictures below.
REMEMBER: don't be scared about cutting/sanding too much, its clay, you can build it back up and start again if you cock it up.
Now to start cutting out, the sides of the mouth and mouth itself. I initially used a craft knife. Nice a light at first the deeper and deeper until you feel you can start digging the clay in that area out.
On this step i added the round circles for the ear cowlings. Simply roll out your clay to the desired depth and use a glass to cut it out and use water to stick them on. While there wet shape them as the smaller curved top on the ear detail is very hard to do when the clay is dry.
The lines and curves on the sides of the helmet can be done with a ruler and a compass or you can have a go free hand, its not that difficult providing you've drawn them on first.
The next instructable on this helmet is the spraying and paint detail, he's going to be the standard light grey and dark grey and will have orange lenses with red LED lights. I may do a battle damaged style paint job however this would mean me digging out my lovely smooth helmet so im not sure i'm brave enough for that. . . . we shall see.
I hope this has been a little bit more in depth than my initial helmet and i also hope it helps anyone out thinking of making THE coolest ornament in a boys lounge. . . . . enjoy.