Help with leak radiator

[Ricky worton]

Recently changed valve on radiator. Where the valve enters the bottom of the radiator its wrapped with ptfe but still has a small leak does this need time to set ? Is it normal for it to leak a little for a dsy or 2 afterwards the leak is slowing and is minor . Thanks in advance

 

[exedon2]

More ptfe required it either holds or it don't. Better still use loctite 55 far superior as a thread seal.

 

[ShaunCorbs]

20 wraps of ptfe required