How to smoothen my finished cowl sclupture?

Hi everyone,

Please help me I've been working on my cowl for over 1 year now and I cannot get it to smoothen enough to cast it.

I was wondering what are the best methods to smoothen my finished clay sculpted cowl
I want to use something like shown in this website http://mycollection.co.nz/batman/cowl2.html

Here are some pictures of what he used to smooth his cowl

My question is what are the steps i need to follow to complete his smoothening process method?
I followed his steps but something seems unclear to me, I dont know how he jumps from the steps of putting the fiberglass to the step where he has a finished product that he can smoothen by sanding, and afterwards what does he use to fill the imperfections? and what does he do to turn it back to silver?(shown in page 3)

Or is there a better tutorial that I could follow altogether?

You can dab a little alcohol onto a rag and slowly smooth it out like that. Or even a damp rag with water should work just remember DONT SOAK THE RAG!

sent from the cockpit of SLAVE I

Keep in mind he didn't spend a ton of time smoothing/detailing his sculpt. He made a throwaway mold of the clay sculpt and made a fibreglass master to work out all the details and get it smooth. This fibreglass master is what he then made a second mold from. To be honest, I'm not really sure why he made a silicone copy with a foam core that he then made a third mold of? If he made the second mold (of the fibreglass copy) correctly, he could make his final cowl directly from that mold.