Radiator tails - how do I stop them weeping!?

[diyAlex]

I think I've got the right words here - the little spiggot type thing that connects a radiator to its valve. Is that the "tail"?

Anyway, couple of new rads - bog standard. A set of TRVs + lockshields for each rad. PTFE tape on the threads. Adjustable spanner (12") to tighten up these tails.

Once in, then the valves are added on using the supplied compression fittings. And of course the other end of the valve is attached to the pipe.

Pressurise the system (boiler reads 1 bar) and these tails are weeping about 4 drops a minute. Drain rad, loosing compression fitting to valve, somehow get the adjustable back in there and tease another 1/4 turn out of this tail. Re-pressurise and still a slow weep.

What's the trick!?

 

[jackthom]

A double layer of ptfe tape will probably make all the difference, all wound clockwise with the thread of course.

 

[footprints]

As above, ptfe goes to almost nothing when the fitting is screwed in, put loads on and then a bit more!

 

[Charnwood]

Loctite 55 string is good, but more expensive than PTFE tape.

 

[diyAlex]

I'll put more PTFE on then - I had given them 3 or so clockwise amounts - but I'll put a whole load more on and see how it works out.

thanks for the suggestions.

 

[Bilabong007]

+1 for locktite 55

I used it on my tails 8 turns then topped it up with ptfe to stop it coming off while I positioned the rad. Goes a bit stringy when tightened I noticed

Graeme

 

[gigz]

If they're old rads i wind the PTFE round 18 wraps, new rads i wrap 12. Then again i think i have PTFE OCD.

 

[Whitespirit66]

I'll put more PTFE on then - I had given them 3 or so clockwise amounts

If you mean you only put 3 turns on there, that's your problem. You want triple that amount and maybe a turn or two more.

It's cheap enough. Don't be shy with the PTFE!

 

[easyflow]

Hemp and boss white

 

[bazdaman]

Im also have an OCD with ptfe 18 wraps usually,
Does anybody else have to tear the first bit of ptfe off the roll each time you use it? Or am i just a wierdo?

 

[Whitespirit66]

Does anybody else have to tear the first bit of ptfe off the roll each time you use it? Or am i just a wierdo?

Yes, because last time I used the roll, I pulled the reel to snap the tape off. This stretched the first bit of tape, and I want it flat for the next thread.

Suppose that makes me a confirmed weirdo with OCD too.

 

[bazdaman]

I dont feel as wierd now but you must always start with a clean flat bit

 

[Charnwood]

Tear, snap? Haven't you heard of scissors?

 

[Galoka]

Scissors? that's a bit technical Charnwood.

I like Loctite 55 cord for thread sealing, esp. useful as you can back it off a little to get things lined up right.

 

[mfarrow]

I had a problem rad this summer, tried PTFE on it thrice, and I wasn't shy of it the first time.

In the end I gave up and called in the big guns (the Loctite 55). That cured it first time round, no messing. I suppose I should use it each time, mostly it resides decorating my bag!