How do I private Anvils? [penguin]

I've seen other people with private anvils and I don't know how to private mine, I've placed a sign on it, left it alone; nothing.
I've done
[private]
Cheshire_Roxas
still nothing,
I've tried placing a trap door on the side of it and then place a sign on it; It wouldn't let me place the trap door.

I don't know what else to do to private it, help please :3 ?​

 

You have to place a fence gate on top of the anvil then type [Private] Cheshire_roxas

 

Thank youu~!​

 

No Probs

 

Locking and archiving.