Cast-iron rads

[Riley]

Been installing four reclaimed cast-iron radiators for a customer.

To say they've been a nightmare is a bit of an understatement. Couldn't shift any of the old configurations pipework and caps so I have been forced to drill and tap them so that I can set them up with the flow and return bottom option.

I have now pretty much got them fully installed however two of the newly tapped holes are leaking I have tried every joint sealing method I can think of. Does anybody have a foolproof method to seal these bloody things??

I have tried in no particular order , PTFE, gas PTFE, hemp and boss white, Loctite, even a bit of a lsx. Still nothing.

Does anybody have any alternatives here as I'm starting to pull my hair out a bit

 

[rpm]

May not be your new fittings but maybe you`ve just found out why they were discarded.

 

[Riley]

Ha ha damn you, you could be right.

 

[rpm]

Ha ha damn you, you could be right.

Which makes extra work chargeable for Yes?

 

[Riley]

Oh she will be charged accordingly don't worry it's more my time of which I don't have much spare of the moment

 

[ShaunCorbs]

you tried locktight 577 as its good stuff but boss white and hemp wont seal it that would be worrying me your sure its not cracked ?

and how many drill bits you gone through

 

[Riley]

It's just frustrating because there is no reason at all why they shouldn't seal The thread tappings are nice and clean all cut with a new half inch tap

 

[ShaunCorbs]

It's just frustrating because there is no reason at all why they shouldn't seal The thread tappings are nice and clean all cut with a new half inch tap

dont want to seem stupid but you checked the threads with a flash light? and there are defo no cracks ? if its all good loctight 577 should do it let it set for 24 hours before pressure and you will be ok

 

[Riley]

you tried locktight 577 as its good stuff but boss white and hemp wont seal it that would be worrying me your sure its not cracked ?

and how many drill bits you gone through

Definitely not cracked and I don't think I ruined even one drillbit. The most difficult bit was getting them into some sort of a stand to hold them up right while they were drilled. Forgive me Shaun all the joints on these radiators that I haven't had to take apart appear to be made up with hemp have I misread the situation

 

[Riley]

dont want to seem stupid but you checked the threads with a flash light? and there are defo no cracks ? if its all good loctight 577 should do it let it set for 24 hours before pressure and you will be ok

I will give that a bash mate The threads are absolutely sound as a pound I checked every single one over as I didn't want to give the customer any comeback on it

 

[ShaunCorbs]

I will give that a bash mate The threads are absolutely sound as a pound I checked every single one over as I didn't want to give the customer any comeback on it

if there threads are good then 577 will seal, may be stupid but the thing your treading/ tightening in (rad tail / air plug is good, threaded wise)????

 

[Riley]

The 1/2 - 3/4 rad adapter looks fairly decent. Ran it through my 1/2" die a few times to make sure so not sure that's the problem

 

[jonnyswamp]

Is it the 1/2 " tail that's leaking, or the adapter
If it's the tail, can you use a shouldered type to get a better seal

 

[Riley]

1/2" male valve screwing into newly tapped female thread in radiator

 

[rpm]

BSP & BSPT mixed up, sure it`s not but just throwing that in the ring so to speak.

 

[Riley]

BSP & BSPT mixed up, sure it`s not but just throwing that in the ring so to speak.

Nah thought that too :smile:

 

[oz-plumber]

Are you roughing up the thread on the tail?

Found that with cast iron threads, the cast is very sharp an just tears the ptfe tape off the fitting.

Have found de-burring the outside of the cast iron female thread helps get tape inside thread.
You may also want to run a gal fitting in and out of the thread a few times to loosen nit up a little and take off any sharp edges.

 

[Riley]

Are you roughing up the thread on the tail?

Found that with cast iron threads, the cast is very sharp an just tears the ptfe tape off the fitting.

Have found de-burring the outside of the cast iron female thread helps get tape inside thread.
You may also want to run a gal fitting in and out of the thread a few times to loosen nit up a little and take off any sharp edges.

Good shout mate I'll give it a bash