How do you apply Smooth Cast to the outside a cardboard helmet?

[Jgbeerman]

I was wondering how people put a layer of smooth cast on the outside of the cardboard helmets? Can it just be painted on or is their a better technique? I understand slush casting for the inside, just not sure for the outside.

Thanks

 

[Jgbeerman]

I found a good vid on youtube XRobots - How To plastic coat foam & expanded polystyrene prop and costume pieces - YouTube

i wll follow those directions!

thanks for looking