Sexing Silkies

I really want to get hold of a couple of Silkies,
My husand bought me an incy and I bought some fertile eggs, But am now worried about being landed with cockerals. I cant see them being easy to rehome. So then thought about day old chicks, but how old are Silkies before you can tell the sex?

when one lays eggs and the other crows you can be sure they are really hard to sex early on and a lot of people have been caught out when their little girl starts crowing  

POL is the best way to be sure I'm afraid. One of my araucanas has just turned out to be a boy - she/he suddenly started to crow and tread the girls and she is about 9 months old  Wish she had grown the tail feathers so I would have had an earlier idea but she still looks like a girl but doesn't now behave like one