knarf3

Hi all I have a problem with a leak on the thread of my new radiator valve. I fitted it yesterday and used PTFE tape but once I did it up It had a leak and when I removed the male thread of the valve it seems as if the thread is cutting the ptfe tape rendering it useless. This morning I put boss green around the thread and one wrap of PTFE tape but I still had the same problem. The thread seems quite sharp and runs quite deep. How much tape should I be using? and are there any other tips? Many thanks Frank