So I fitted and tested the new radiator. Apparently only brass compression elbows are suitable with these nice black coated brass pipes I have. Previously copper and pushfit elbows were used (left and right sides respectively) which weren't suitable. The brass elbows are fitted nice and tight but can I wrap PFTE tape around the compression elbow connections just to be safe? When I tested the radiator it all seemed dry and no leaks but I may have noticed a drop or two on blue paper towel I placed under the pipes to detect water. @terrymac this is the same radiator you advised me to use compression elbow fittings for.
I personally wouldn’t use ptfe on compression, I would loosen the nuts back off and smear lsx jointing compound around the olives before retightening. https://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614
Compression fittings don't need PTFE tape ,as ppmacca advised above,a smear of LSX around the olive before assembly ( or re assembly). If the joint has a tiny weep ,tightening up a tad will very often sort it.
Thanks guys. I think the tiny weep may have been sorted by tightening the bolt. But will it hurt though if I wrap PFTE on top of the bolt as like insurance? As PFTE tape is the only thing I have lying around.
Btw noticed that LSX states external leak sealer so if I really can't use PFTE tape then can that be applied externally without taking the compression elbow apart? Would hate to have to drain the radiator and system again if I have to get to the olive.
No ptfe wrapped externally will not help at all. LSX can be used as an external leak sealer but I don’t think it’d be suitable in this case, and I wouldn’t trust it in this way as a long term solution anyway.
How can he wrap PTFE tape around a compression nut , the fittings thread possibly , but given he doesn't want to drain down ,and is looking for an external solution ....I am confused !
Okay just retested with heating on. Used a blue paper towel to detect any water droplets and all seems good, leak and weep free on the compression elbow joints. BUT noticed a slight leek from radiator itself where the return is connected. See pic please. I guess this defo requires PFTE tape right? And how many turns? I reckon I may have loosened it when I was tightening the other nut next to it. If I have to drain and take radiator off to fix this then might as well buy some LSX and paste it on the compression olives while I'm at it just for that extra reassurance.
The amount of turns of PTFE on radiator tails varies quite a bit from one rad to another, a dozen or more is usual,and smear LSX on the thread. You probably won't need to drain down to take that tail out. Close both valves and do not open the air bleed valve. The water in rad will be held by vacuum.
I’d be looking 18-20 turns of tape, wrapped tightly clockwise, and I’d then put a smear of lsx on the tape too before making into the radiator.
I think He meant would it offer extra protection if he wrapped it around the nut and covered the fitting, after the fitting was all made up.