andyv wrote:
I'm trying to plumb up an old cast iron radiator. I've got 2 new 1
1/2" threaded inserts which screw into the body of the rad. Into these
go the valves.

I've used PTFE tape on the threads but don't seem to be getting a
sealed joint on one end. Is there a technique for this? Alternatively
there's a cement called plumber's mait, which I think might be the
sealant originally used on cast iron rads.

You do need a lot of PTFE tape. 8 - 10 turns sometimes. Plumbers Mait is
wonderful stuff for cistern/pan joints, waste pipes etc.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk