Rookie Error... Can't seal Cast Iron Radiator Bush

[wmdixon]

Fitted a new Cast Iron Radiator today. The problem is that the Bush is weeping. :sweatdrop:.

Any ideas on the best way to seal the leak?

There is a drip every couple of minutes or so. The customer wanted the heating back on for the evening so I've had to leave it overnight.

I had the system filled up and drained down three times. Initially I just had the bush hand tight, then nipped it up a bit more, finally I got the stillson's on it. Think I might have over-tightened it now!

I'm going back in the morning and planning to get some sealant in their. Possibly, a PTFE paste or boss white. Has anyone got any ideas or suggestions?

Thanks, Billy

 

[SimonG]

So you didn't use any ptfe or paste on it then?

 

[Whyme]

Ptfe with a ptfe seal on bush threads works a treat, i always put a splodge of ptfe paste along side tape on threaded fittings. never any probs ( unless you have to undo it).

 

[wmdixon]

Used plenty of PTFE on the Rad Valves... no problem there.

The instructions for the bush said it was a dry joint and no boss white or PTFE should be used.

 

[wmdixon]

Cheers for the quick replys... i'm hoping PTFE tape will sort it.

These are the instructions I was following... any idea why they say not to use it?



If the bushes are supplied loose they must be fitted to the radiators before installation of the radiators.
Note: two out of the four bushes have left handed threads and must only be fitted into the appropriate ports.
Use only the sealing rings supplied for sealing the bushes, air vents and plugs.
No thread sealant paste or tape must be used on the thread of the bush or seal which mates into the radiator.
When fitting radiator valves to the left-hand threaded bushes; hold the bushes firmly with a spanner. This will
ensure that the bushes are not allowed to rotate and become loosened, thereby preventing the risk of leaking.
It is recommended that the threaded tail pieces of radiators valves or other pipe fittings that are screwed into the
bushes are sealed with PTFE thread sealing tape. Sealing compound can also be used but great care must be
taken to ensure that there is no contact of the sealing compound onto any of the sealing rings.
Each radiator is supplied with a bush & washers for each of the 4 connections.

 

[Whyme]

I think where the two section meet there is a seal, been a long time since i fit those sectioned columns.

 

[wmdixon]

Flash Vote:

Fix leaking cast Iron radiator bush with:

A. PTFE Paste
B. Hemp and Boss White

 

[Whyme]

wmdixon ya just jogged my memory wind it out a bit and hemp and paste it. good call

 

[lame plumber]

:iagree:

 

[derek hunter]

allways put ptfe on it aprox 15-20 wraps a little bit of boss white and all will be good

 

[wmdixon]

This is the fitting I'm having trouble with...

 

[derek hunter]

ptfe and boss white will sort this

 

[wmdixon]

Cheers... seems like boss white and hemp or ptfe is winning this vote.

The thin rad valve side is fine just the fat connection into the radiator.

 

[Whyme]

That aint the bit that joins the columns, the column joining nipple is the dry joint bit there on about if its only one column then ignore it. like derek hunter says ptfe. or any kind of jointing compound.

 

[Koogatubac]

Put the ptfe on as it winds in the radiator (make sure you put the ptfe on correctly as its going with the threads)

Smear jet blue inside the rad and around the bush (ontop of PTFE)

If done right 99 3/4% it wont leak

 

[derek hunter]

look dont confused just put ptfe and jointing compound boss white /jet blue or whatever
good luck

 

[stevetheplumber]

some of these are parralel threads and should have a flat fibre washer that seals between the rad and the flange but ptfe tape should work as the tape that squeezes out of the thread will form a seal under the flange this one looks like cast iron so unlikley youll snap that but if it ally be carefull as to much under the flange can snap the flange of
just think about where the seal is being made between rad face and back of flange rather than filling the threads

 

[vern]

a differnt answer Loctite 55 string use that and i would'nt even look back to see if there was a leak, because there wont be......Steve will be bang on regards the paralell thread

 

[wmdixon]

Thanks for all the support... amazing to get so many quick answers!

I went back and took the bush off this morning. I noticed the flat washer at the back of the thread was torn... thinking it could have caught on a rough piece of iron. (Top marks go to Stevetheplumber for insight into the workings of this fitting!).

Wrapped the thread with PTFE, mostly toward the back of the thread to account for the torn washer, then smeared with Boss White. All good... job done made it to football by 11am. Thanks to everyone who said PTFE and Jointing compound would work.

Anyway lessons learned....

1. Never over-tighten a fitting out of anger.
2. Always carry a good selection of jointing compound.
3. Charge up when working on expensive gear. i.e. £300 rad.
4. Check washers on fittings before installation.
5. Carry ample supply of spare washers.
6. Come to UK Plumbers Forum when in a spot of bother.

Cheers for the help... here's the finished rad (the little *******)...